----------------------------
Date: Tue, 13 Apr 1999 13:20:15 -0400
From: Brian Neily briann@ici.net
Subject: [D90] Three-link Suspension
I found an article in the March issue of Design News on Three-link
Suspensions. The article is onli ere.
http://www.manufacturing.net/magazine/dn/archives/1999/dn0301.99/05d1805.htm
The online version is missing the picture of a jeep with one wheel drooping 2
1/2 feet.
Enjoy
Brian
------------------------------
Date: Sat, 17 Apr 1999 17:38:19 -0600
From: Nathan Hindman nation@flash.net
Subject: [D90] Twist-Off 99 Pics
Hey, just wanted to let everyone know that I
posted my pics from the Twist-Off and Moab. If
anybody wants to check them out, they're in the
"adventures" section of my site.
http://www.flash.net/~nation/lrover.htm
Thanks,
Nathan
94 AA Yellow D90 #1811
97 Discovery XD
----------
From: Richard Hills[SMTP:rhills@nmsu.edu]
Sent: Tuesday, July 11, 2000 12:48 PM
Subject: Re: [D90] Rich/New Mods...
Doug Aitken,
My wife keeps me on too tight of a budget to go all out. My changes have been
incremental.
Yes, I am happy with my present suspension set-up, but still think there is some
room for future refinement and plan to make some minor changes. However, I have
other things that I plan to do first. I think those hard core D90 owners who have
wheeled with me (including those with 3-links) would agree that I seem to
rockcrawl about as easy as anyone - even though I only ramp around 1000 and have a
hard top. Since my vehicle is a hard top, and since I have a modified radius arm
set-up that has about 67% of the roll stiffness of the stock radius arm, what
works for me may not work for you. I also find that the set-up I prefer for my
35" SSR's is different than what I prefer for 255x85x16's. I run stiffer springs
with the SSR's since I now have a wider track and am higher. So I am hesitant
about making recommendations to the group at large since it depends so much on
your terrain, your driving style, your vehicle set-up, and your budget. What I
would say is if you have stock front arms, you should be softer on the front than
on the back. But don't go any softer than stock front and rear. I found that the
stock front and rear springs work well up to about a inch of lift (through lift
blocks). As you lift the vehicle more, you need to go stiffer front and back to
help control roll.
If you run a modified front end designed to decrease roll stiffness (i.e., the
modified radius arm or 3-link approach), then you must run stiffer springs up
front to control roll and to balance out the suspension.
Believe it or not, you can run near stock length shocks and still ramp near 1000
if the shocks are located just right (stock they are not), and if you have freed
up the front radius arms through modification, and if you have a wider track. You
have to experiment with spacers under the shocks and pick the right bump stops for
your tires and lift.
Presently, I am running my stock rear springs in front (230 lbs/in), have OME
mediums in the rear (seem about 250 lbs/in although they are listed as variable
rate of 250-280lbs/in), have 1.5" coil spacers up front and 1" spacer blocks in
back, have 1.5" spacers under my front shocks (for more droop) and the SG drop kit
under my rear shocks (for more droop), and am running standard 8.5" travel
Bilsteins front and back (I really like their damping rates and quality). I am
also running very tall bump stops to keep my 35" off the fenders (especially
required the rear) and my front shocks from bottoming. My modified right radius
arm has an additional pivot that allows twice the angular rotation of the axle for
the same bushing flex. This results in my left radius arm absorbing about 67% of
torque and the right 33% of torque under braking and acceleration. I can pin the
right arm to make it act as a stock arm for extended highway use.
My shocks are still not ideally located for the large bump stops required to keep
the 35" off the fenders. I could get more droop out of them by lowering them and
do plan to make additional modifications in this area.
Bottom line: If you have lockers front and rear - don't get too carried away with
RTI's above 1000. To get a balanced 1000, you will have to loosen up the front
some through some sort of radius arm modification or 3-link - don't try to get it
all from the rear. If you don't want to modify the front, then shoot for a RTI of
around 900. This will still give you plenty of articulation with good balance. I
have run at both 900 and 1000 and have not noticed a significant difference in
performance (I don't consider lifting a wheel a difference in performance if it
does not hinder me or make me tipsy).
Rich Hills
----------
From: Richard Hills[SMTP:rhills@nmsu.edu]
Sent: Tuesday, July 11, 2000 2:23 PM
Subject: Re: [D90] Rich/New Mods...
If there was no budget constraint, if I had a soft top, and if I wanted to go with
a bolt in solution - my first choice would be the SG 3-link, taller springs all
around with the appropriate spring rates , and roughly 10" shocks with the
appropriate sized bump stop. With my large tires, tall bump stops, and 8.5" shocks,
I actually need the tops of my shocks mounted lower (see the Suspension 101 article
published on the list earlier) to better utilize the compressed length. Or I could
buy longer shocks and not use 1.5" of their compressed travel if I can find shocks
that I like. I have tried the Ranchos and don't like their damping as much as my
Bilsteins. My lower modified mounts are already as tall as I want.
Remember, don't get too carried away with anyone's recommendations (especially
mine). As long as your vehicle is balanced; f&r lockers, sticky 35" tires, driver
skill and experience, and spotter skill have a much bigger impact on rockcrawling
performance then moderate differences in spring rates, lifts, and 200 pts on the
ramp.
Rich
----------
From: Richard Hills[SMTP:rhills@nmsu.edu]
Sent: Thursday, July 20, 2000 12:39 PM
Subject: Re: [D90] Center of Gravity
Q,
If you raise your vehicle by 2" by longer or stiffer springs, then your
cg raises a little less than 2" (your axles have not been raised, so the
overall cg raises a bit less than 2").
The important quantity for static lateral stability is the ratio of the
cg height over half the track width. So if your cg goes up by 2", your
track must increase by 4" to maintain the same lateral static stability.
However, the proper way to measure track for lateral stability purposes
depends on the tire pressure. If your tires are rock hard (i.e.,
inflated to 50 psi) and you are on hard ground, then you can measure out
to the outside of the tread. If the tires are at low rock crawling
pressures, and they are radials, then a measurement out to the center of
tread would be more appropriate.
Rich
Rich later added:
At rock crawling pressures with radials, you need the decrease in backspacing
plus half the increase in rim width to equal your lift. So if you lift 4", you
need 4" per side. Going to 10" rims from 7" rims moves your half track out 1.5"
(half the increase in the rim width at low pressures). Thus you would need 2.5"
less back spacing or a back spacing of 2.875" to regain that stability. This
would really expose your disk brakes to trail damage.
----------
From: Gomes, David
Sent: Thursday, July 13, 2000 12:03 PM
Subject: RE: [D90] Rich/New Mods...
Adam,
Of course, we all have our own tastes in what we describe as the "ultimate" handling rig, but I can see the possibility for some misunderstanding when you say:
"...The thing I dont understand is why people go crazy over having super high RTI suspension systems when they have lockers front and rear......With lockers, you always have 25% power at each wheel, all the time....."
What actually happens with the fully locked rig is that engine torque is delivered through the drivetrain to each wheel in DIRECT proportion to the percentage of total available traction that is available at that wheel. In the full open drivetrain, torque is delivered in INVERSE proportion to the percentage of available traction that is present at each wheel.
A few cases to illustrate:
1- all four wheels on level ground with equal traction - both systems deliver 25% of the torque to each wheel (this is oversimplified, but basically true if we leave out effects of weight distribution, torque biasing due to engine rock and drive line wind up, etc.)
2- one wheel in the above system lifts (ignoring weight transfer) - One wheel now has 0% of the total available traction, and each of the other 3 have 33.3% of the total available. The open system delivers in inverse proportion, and so delivers 100% of the torque to the wheel with 0% of the traction. The locked system delivers in direct proportion, and so delivers 33% of the available torque to each of the grounded wheels, and 0% to the lifted one.
3- Only one wheel having virtually all of the traction (impossible, but we could get close, say on ice, with one wheel on dry pavement) - The unlocked system dumped all the torque out the first wheel that lost traction, so that system is still the same as in #2, immobile. The locked system is still delivering in direct proportion, and so is now sending 100% of the available torque to the one wheel that has 100% of the total available traction.
As we can see, if the system was originally fully open, this served as a torque limiter in the original design, such that the components didn't need to be designed with any more strength than would be required to transmit 25% of the engine's torque (again oversimplified, but you get the point...). Put lockers in that system, and those components (axle shafts mainly) can now see nearly 100% of the available engine torque. This is why folks like Ashcrofts and Bill Davis (Great Basin Rovers) are in business. But, as good as their components are, they can still be broken.
Keeping more wheels on the ground divides the loads between more contact patches, and lightens the load on each individual component in the drive line, making each less likely to fail. Add in the fact that each point touching the ground makes the vehicle more stable in any given situation, and you get a good picture of why folks try to keep the wheels on the ground, and not just buy the stock truck, throw in 2 ARBs and conquer everything.
There are a million combinations of components out there that can allow you to "have you rcake and eat it too". We have lots of friends on the list and off developing and testing things all the time. It's not a simple choice between good road handling OR awesome trail performance. Thanks to guys like Doug M, Rich H, Greg J, Quinn D, Alan D, Q, Bill D, Chris V, etc, we're getting closer all the time to really having it all. It's the great mix of opinions and desire to try new things that keeps this development happening.
Rover On!
-Dave G
------------------------------
Date: Mon, 19 Apr 1999 03:35:22 EDT
From: RVRBRUCE@aol.com
Subject: Re: [D90] Re: wheels/suspension upgrade
I run ARB heavy duty springs in front and medium duty in back with 1/2'' Rockware spacers. I have 33" BFG mud terranes on steel rims. I have not changed the turnstops. I have removed the swaybars and am using OME shocks. I get some rubbing on the radius arms at full lock. I am very happy with my setup.
----------
From: Doug Aitken[SMTP:jdaitken@earthlink.net]
Sent: Thursday, April 13, 2000 10:21 AM
Subject: Re: [D90] Self-Installing Suspension Upgrade?
At 08:52 AM 4/13/00 -0700, Nadir wrote:
> I'm thinking about picking up a suspension package (probably Safari
> Gard Stage II, maybe Desert Rover). I was wondering what the list's
> wisdom is regarding the difficulty of self-installing that sort of
> gear. I've managed OK with things like sway bar disconnects, skid
> plates, tire carriers - the "bolt-together" stuff. I'm OK with drills
> and grinders, hammers and ratchets. How would you think I'd do with a
> suspension system?
Nadir; My opinion is that you MUST do it! It's the only way you will be
confident that you know what is involved! The more wrenching you do on your
vehicle, the better you will know it and be confident in it's abilities.
Never mind the welding thing! Many kits require a very small amount of
welding, but it is easy to get a specialist to do this, while you do the
wrenching. However, it is WAY better if you have help! one person will have
a much tougher job with suspension upgrades! Check around on the list for
other D90 owners in your area: (Usually!) they will be willing to help with
an install (for beer 'n' pizza!!!) and you will gain some wheelin' buddies
at the same time! Here in Houston, we hang out in Alan Dobb's workshop and
work on all our vehicles most weekends and have all learned a bunch! Check
out Alan's website (www.yellowdefender.com) as well as Q's site for some tips.
BTW you need to have a decent jack, jack stands, etc....
NEVER try to do any suspension mods with the truck lifted on a jack: you
must have jack stands to get under the truck!
Good luck and have fun!
Doug
'95 Red Defender 90 5-speed
-----------------------------
Date: Sun, 18 Apr 1999 23:33:11 -0500
From: daitken@sugar-land.anadrill.slb.com (Douglas Aitken)
Subject: [D90] Wheels/suspension upgrade & MORE!
>Hi Bob,
>I will send you everything I get. Unfortunately, I haven't exactly had the
>barrage of information I expected. I'm starting to think maybe the list is
>used mostly to pass on snide remarks and vendor websites, the latter of which
>I get hours of enjoyment.
Art: don't be so tough! One of the problems with topics like DR vs.
Rockware is that we have a "been there/done that" problem. We had a very
hot discussion of this some time back (until we were "Bonnered" to death:
oops - inside joke for the old guys). In a nutshell: they both do the same
thing: allow the rear springs to drop free and therefore allow much greater
rear wheel articulation. Are they effective: it looks like yes! Many happy
users (include two of my closest wheeling buddies). Which to chose:
whatever you wish.... Are there drawbacks???? I am not a suspension
engineer: Rich Hills is the man to give a technical explanation. But I have
reservations: not about either DR or RW: just about the concept of very
large suspension travel, which I will address later in this (as usual, long
winded) reply....
>When technical information does come across, it's
>usually way over my non-mechanical head. I hope I never have to pull a
>driveshaft or drop my transmission, but at least I know If I ever do, there
>are people here who can assist me with that.
With more than advice, too. One of the best things about owning a Defender
is that we are almost all nuts and love to tinker. If you have any buddies
close by who own D90's, they will pro'lly also be happy to crawl under your
truck with you and explain all the wiggly bits..... ;~)
Some of the best fun our gang has is getting together in Alan Dobbs' shop
and working on our Rovers. I hope you have the same luck. Believe me, as
long as you are not talking MAJOR stuff, the D90 is fun to work on (at
least Drivetrain/suspension). And if you are close to Houston: come on down!
>As far as getting some of these
>Rover gurus to just drop a note, as to how they like their respective
>suspension upgrades on a day to day basis, I haven''t had much luck.
See above!
>Now that I've said my peace, I'll give you my tentative game plan:
>First I plan to start with Old Man Emu springs - heavy in front, medium in
>rear - heavy in front because of my ARB bull bar/winch combo.
>I will then add the OME shocks - I am going with them for now because I don't
>plan to put the Rockware or Desert Rover stuff on until maybe as late as next
>summer.
Good plan! I suggest you
(1) call ARB directly; (206) 264-1669 and ask to talk to Chris Wood. It was
a buddy of his - Jesse Rodocker- whose truck did so well at the Twist-off.
I think he had some Safari Gard parts and OME springs/shocks. Seemed to be
a pretty nice, balanced effort. Maybe Chris can tell you exactly what parts
were used. He certainly will advise you on the Springs/shocks. BTW, OME
have recently changed all their springs, so make sure you get the new
stuff. If you go to your local parts store, they may have old stock......
(2) call Bill Burke, who sells OME/ARB stuff. Prices are good, service is
excellent, advice the best in the business! Check out his website (the
ARB/OME bit) at:
http://www.bb4wa.com/recomm.html
>Next I plan to fit 33" tires - this is where I really need someone who is
>running them to tell me if I need more lift, different backspacing, and what
>I need to do with my bumpstops. It will also help me to decide if I should
>switch to 15" rims.
As I said: you can go 33" without any changes other than the steering
bumpstops. The advantage of going to 15" wheels is that it opens up a vast
array of tires at better prices! But you are going to pay for a set of rims
and may have difficulty getting rid of your alloys...... You can of course,
get dedicated hard core tires on your 15" wheels and keep your stock alloys
with the AT's ......
>After, or maybe right before the tires, I plan to add the Fabitron sway bar
>quick disconnects and rear radius arms. I have heard really good things about
>them from a couple people I know that have both.
As I said before: removing the rear sway bar will not noticeably change the
handling of your vehicle. Don't spend the money on the rear disconnects
(unless they only come as a set front/rear: I got mine 2nd hand). Just take
the whole rear swaybar off. If you are unsure about this, try pulling the
bolts which connect the swaybars to the drop links, swivel the sway bar
back and secure it to the back bumper with a bungee cord or piece of wire.
Drive around and see if you notice any difference. I didn't and finally got
round to tossing the whole thing.... In the front the disconnects are
useful as the sway bar does improve the trucks stability in lane
change/fast swerve situations. But the truck (with stock suspension) is
perfectly safe without them as well: it just leans a bit more in curves....
>At that point I will make the decision whether to add ARB lockers or go with
>one of the aforementioned suspension packages. I think the extremely long
>wheel travel is really cool, but I am worried about the long term effects on
>the vehicle.
OK: Here's where I am going out on a limb: For those of you who stayed with
me until now, here is some personal impressions (Yuck, I hear??) which will
possibly cause some further discussion!
On two recent occasions recently (Chris Hinkle's "white 'un" at 21 Road,
Alan Dobbs's Yellow Sub today!), I have seen a rear radius/trailing arm
fold up. Common occurrence with stock arms, which cannot take much. Lots of
options out there to upgrade. The Fabritron has a swivel joint close to its
forward end, which is still secured by the rubber bushing. This makes axle
drop easier, but around the (preferential) swivel, effectively shortening
the radius arm. As Chris Hinkle pointed out some time back, this is not a
particularly good thing, as you are changing the geometry of the rear
suspension slightly.
OK: here goes with my personal impression, coming from the two incidents I
observed, and watching the rigs on 21 Road. In certain situations of large
drop of one rear wheel, it seems like you can actually get to a point where
applying torque to this dropped wheel will cause it to walk forward using
the radius arm as a crutch: all of a sudden, the body is hoisted up even
higher, the radius arm doubles and the axle twists off the rear drive
shaft U-joints.
So what is the point: Maybe there is a limit we should allow our axle to
drop and the new long-travel suspensions are allowing too much drop, with
the type of result described above. I am sure the suspension gurus can
clarify the dynamics of this (and give a solution: like limit straps?), but
I for one do not intend to do anything radical to the suspension without
paying very close attention to strengthening the radius arms (and will
probably not go for a "free" back end like RW or DR without putting a limit
on the drop).
Now, please! lets hear some comments!
Doug
Doug and Kim Aitken
'95 Red Defender 90 5-speed
'95 Aspen Silver Range Rover 4.0
----------
From: Q[SMTP:q@d-90.com]
Sent: Wednesday, June 14, 2000 1:25 PM
Subject: [D90] My suspension was: Austin Power's D-90
Well, after much thought and calculation, this is what I'm doing.
I have the bearmach MD springs now (about 1.5" lift) and I've purchased a set of HD bearmach rears. I'm going to move my current rears to the front to get more lift and stiffer rates. The current spring rates are 195 front / 240 rear. I'm going to but the 240's up front and new 290lb springs in the rear. If all my calculations are right, I should have around 3.5" of lift and need to use some of the OME poly spares to level it all out. The reason I but such a stiff rate is because the people I've talked to with 3-link's say that it needs stiffer springs up front.
For shocks, I'm using Warn Black Diamond XT's. Some people claim that they are weak, but my current set have gone way beyond the call of duty being the limiting factor for both up and down travel. I had bottomed them out hard enough a couple times to bend the SG drop kit.
I've decided to go with the "less is more" and run 10" travel shocks at all corners. The rear shocks will be 788066's which are the PERFECT length for the stock mounts. They should hit the bumpstops just before full compression, and the specs say they have 10.32" of travel. For the front I'll have the 788043 shocks which are 10.52" of travel. You could also use the AT shocks which aren't quite as beefy, but offer a little longer stroke at 10.82".
The key is that these shocks use the stock mountings, and that of course is cheap.
The shocks are around $200, and the springs are $55 each from DAP.
-Q
-1995 Red Defender 90 #2069
----------
From: Louis Goldring[SMTP:louman@home.com]
Sent: Friday, February 18, 2000 4:02 AM
Subject: [D90] Re: Suspension?
Jamie,
With the Desert Rover suspension you can run 35" tyres, I have been
doing so for about 2 years, and the DR will only lift the vehicle about
an inch, so you'll keep most of your low center of gravity. Also, the
DR retains the factory shock angle so you will still have a good ride on
the highway. Good Luck.
Lou Goldring Jr.
--------------------------------
From: Bill Ritchie billnsandi@kingwoodcable.com
Sent: Monday, January 17, 2000 3:15 PM
Subject: [D90] Spring and Shock Choices for SG 3 link
I am currently waiting on delivery of the SG 3 link front suspension for my D90 and had a few questions about spring and shock choices. I currently run the Desert Rover setup with OME light duty springs up front and Rancho 9014 shocks (standard DR fare). I am concerned that this spring and shock combo will not give me much more front end flex (read droop) after installing the 3 link.
Has anyone installed the 3 link on a vehicle without also having the SG stage 2 or 3 suspensions? If so what do you have and how did things work out? I will probably install rear med. duty OME's on the front (about 2" longer spring) and put a spring spacer in the back (1" since the front sits 1" lower than the rear currently). Any thoughts about this?
Also, when installing the 3-link a weld is required on the crossmember under the transmission/transfercase. Can the rockguard/link combo be installed and the vehicle driven to a welding shop with the OEM radius arms still in place for the necessary weld? Or can you install the components, mark their positions then remove the crossmember and link for transport and welding offsite?
Bill Ritchie
'97 D90 ST AA Yellow (SG 3 link on the way!)
------------------
From: "John C. Hinkle" defender110@email.msn.com
Sent: Monday, January 17, 2000 5:28 PM
Subject: [D90] Spring and Shock Choices for SG 3 link
Bill-
I've had the SG 3-link in place for about 10 days now. You will need higher spring rates in the front to reduce sway around corners and diving with braking. Can't say whether shorter springs will work with the setup - I'm using the longer SG ones on my yellow 90.
I had my bracket tack welded in place at the Off Road Shop then went home and put the kit on. Then drove carefully back to the Shop to have the bracket welded up. Please note the bracket does NOT go in the center of the cross member :)
Chris Hinkle
----------
From: Bill Ritchie[SMTP:billnsandi@kingwoodcable.com]
Sent: Monday, February 07, 2000 6:51 PM
Subject: [D90] 3-Link Install Thoughts and Observations
I installed the SafariGard 3-link (sort of) this weekend and had some interesting thoughts and observations. First of all - It is not a one man job (thank you to Alan Dobbs, Doug Aitken, Antonio Manega, and Allan Madar (of Redhummer.com fame)).
We took off the stock radius arms and hoisted the front (from the top tube of the ORS bumper) of the D90 with Alan's large A-frame to see what kind of travel the front axle has with no impedement (except for the shocks). Well with Rancho 9014's (25"x15" - 10" travel) the front springs (OME 761's (front med. duty)) were completely loose in the spring mounts with about 1 to 1.5 inches of vertical play. hmmmmm
We also took off the rear tierod completely to fit a new one. The old tierod was a Fabitron Oversized Chromoly unit that had seen some serious thrashing and was bent in 3 or 4 places (but still amazingly pretty straight). While removing the tierod I noted that I should have put antiseize on the threads when first installing it, as it was a major pain to get the rod ends loose.
Once that was done, Antonio and I with Allan Madar's excellent guidance carefully (with a sledge hammer) guided the rockgard into place onto the radius arm mounts and the bottom of the 3rd member. After securing it in place and installing the center link, the position of the bracket for the center link was carefully marked on the transfer case crossmember with a paint pen. Then everything was removed, and the stock front suspension was replaced so I could drive home (as this was Sunday and we had no access to a professional welder). The whole process took about 4 hours (including time to adjust the front wheel toe in).
Soooo, now I need to stop by my local welding shop and have the center link bracket welded into place, and do the whole thing over again.
Tomorrow I am going to order some rear medium duty OME springs and use them on the front (about 2" longer and higher spring rate). That should prevent the springs from popping out with the increase in front end flex with the 3-link. Also, per Chris Hinkles suggestion it will provide some firmness to the front end that will now be somewhat "softer" with the 3-link and no swaybar. I also will order some 1" rear spring spacers to make up for the difference in lift front to back (currently I sit 1" low in front - should level things out with this new setup.)
It continues to be a work in progress, any suggestions or thoughts are always appreciated.
Bill Ritchie
'97 D90 ST AA Yellow (SG 3-link sitting in the garage)
----------
From: Bill Ritchie[SMTP:billnsandi@kingwoodcable.com]
Sent: Thursday, February 17, 2000 3:46 PM
Subject: [D90] 3 - link Install last night - thoughts and observations (very long)
Well,
I finally did the 3-link install last night (with the continued help of
Doug Aitken and Alan Dobbs, as well as Alan's super duper
workshop/machineshop).
1st part of the install involved lifting the rear with a forklift to remove the old rear springs (OME Med. duty rears) for use on the front, and placement of a new set of OME Med. duty rears (new one's were about 1/2" taller than the old one's) on top of some Rover Accessories 1" spacers. Install was straight forward, however longer bolts were needed to pass through the spacer and the bottom spring perch. Now leap forward to the end of the installation with both sets of springs in place (ome med. rears (old one's) on the front and ome med. rears on the rear with a 1" spacer). Ride height is now about 2" higher in front and about 1.5" higher in the rear (compared with old ome springs (light duty in front and med. duty in the rear). Front sits about 1/2" higher than the rear right now (D90 has the offroad shop front prerunner bumper and a warn 9000 winch).
Spring back to the middle of the install - The D90 was returned to Earth and driven into the shop under Alans huge A-frame support and lifted about 8 feet in the air from the front bumper with a chain hoist (picture a giant fish hanging from a very large fishing pole). This fascilitates easy access to the whole front suspension while standing up. The front tires were removed, then the passenger side of the rear tie rod was loosened (requires several hard hits with a hammer on the cast iron bracket that holds the ball joint), then removed. Interestingly, the front springs were both falling out of there perches with the front end completely off the ground (shocks had more travel than the springs would allow (Rancho 9014's - 10" travel)).
Next, the axle was supported from below with two jackstands sitting on top of a very large heavy steel tool box, and the D90 was lowered until the axle just rested on the jackstands. The radius arms were removed (saving the big washers for use later). (At this point the front shocks were unbolted and the new springs (old OME rear med. duty) were installed).
Per the SG instructions you are supposed to drill and tap the two holes under the pinion on the 3rd member, but I had already done this when we had the 3rd member was out for the ARB install. The rockguard portion of the kit is then slid into place using the radius arm mounting brackets (the tabs go outside of the inside bracket of the radius arms). This reqiures some patience, and some big hits with a sledge hammer (and a friend helping doesnt hurt either). Once this is done each hole is lined up and secured with a massive bolt (6 total) to the radius arm bracket then a spacer then the other half of the bracket then a supplied plate which matches the rock guard bracket. After it is all tightened then you must bolt the bottom of the rock guard to the bottom of the 3rd member where you drilled and tapped the existing 2 holes. On my machine the rock guard sat about 1/4" from the mounting surface and required the fabrication of a small plate to secure it properly (thanks Alan). Additionally, the holes in the Rock guard did not align perfectly with the drilled and tapped holes, so they had to be widened slightly with a grinder.
With the rock guard in place, we attempted to replace the tierod (still with driver side attached and passenger side free). No amount of shimming, twisting or swearing would allow us to get the tie rod to fit back into the bracket on the passenger side. We ended up removing the entire rod from the rod ends, then secured the rod ends to the brackets, then screwed the tierod into both tierod ends at the same time (keeping the securing nuts in the same position so we didn't have to measure toe-in again).
Next we installed both radius arms (small tube side down for D90 per instructions) and tightened them. We then replaced the tires, let the vehicle down off of the a-frame onto the ground, and cleaned up the mess we made (lots of metal fillings from the die grinder - stickers in the hands, arms and buttocks - ouch).
With the D90 sitting on the ground we installed the center link (skinny tube forward, and grease fitting up) and started with the suggested length of about 20". I had previously installed the entire suspension as a test to find the position of the center link bracket (which is welded on), and about a week ago had my local welder (someone I trust) weld the bracket on (little skid plate down). With the center link bolted on, we checked the pinion angle and drive shaft angle with a with a gravity compass (driveshaft 16 degrees, pinion angle 11 degrees). Since I don't have CV jointed driveshafts the SG instructions were somewhat sketchy about what angle was optimal so we took it for a test drive to see if anything untoward happened.
Right from the start there was noticeable driveline vibration at about 20 mph and 50 mph, but the tracking was perfect and steering was great. We adjusted the pinion angle to 13 degrees and some of the vibration disappeared, but it still needs some adjusting. The vibration could be attributed to the increase in lift from the new springs (about 3.5 to 4" over stock height). But I will still fiddle with the angles to see if the vibrations can be fixed.
After a day of driving (highway, around town) I have been pleasantly suprised by the 3-link's on road handling. Several listers had mentioned that the front end is "looser" on road, but mine seems firmer (prolly because of the higher spring rate in the rear springs I am using up front). Tracking on uneven pavement and steering is much better that before the kit was installed. Besides the aforementioned vibrations the only other complaint I have is that (like Doug M.) I have a slight clunk in the suspension on accel. and braking. I will attempt to sort this out and try out various pinion angles (If anyone has some ideas on this subject please chim in).
I did some extensive measuring with a ramp and forklift prior to installation and will do the same post-install and let everyone know the differences. On road and offroad driving impressions will follow.
Bill Ritchie
'97 D90 ST AA Yellow
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From: Bill Ritchie[SMTP:billnsandi@kingwoodcable.com]
Sent: Friday, February 18, 2000 3:50 PM
Subject: [D90] 3-link Update and info
Just a short note to let those interested know that I solved the clunk in the 3-link while accel and decel - turns out the radius arm bushings were not properly seated in the mounts and some front to rear slop was present. After tightening that and all the other bolts the clunk went away.
What I still have is alot of driveline vibration. Some of which is probably due to the additional 2" lift, and some due to improper alignment of the pinion angle. Since I have oem driveshafts and not cv jointed driveshafts the pinion angle should be parallel with the output shaft of the transfer case (according to Tom Woods site http://www.4xshaft.com/ and Six States site http://www.sixstates.com/). I had mistakenly assumed that my driveline vibration would be lessened by decreasing the angle of the driveshaft to pinion by raising the pinion with the 3-link. This should only be used with a cv jointed driveshaft (pinion angle should be parallel with the driveshaft for this application).
I will straighten out things and report back about driveline vibration in the next few days. If I can't minimize it by the time we go to the Chile Challenge then I will likely revert back to the former spring combo (OME light duty fronts and OME med. rears). If I do this, then I will have to somehow retain the top and bottom of the front springs, as the increased travel from the 3-link will unseat the springs at full droop.
Always a work in progress,
Bill Ritchie
'97 D90 ST AA Yellow
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From: John C. Hinkle[SMTP:defender110@email.msn.com]
Sent: Wednesday, February 09, 2000 4:26 AM
Subject: Re: [D90] 3-Link Install Thoughts and Observations
> I also thought the center link was adjustable??? So, after you weld in place you can adjust it > in place you can adjust it in case of a problem. NOT
Actually, if you put a bottle jack under the area where the two bolts hold the tie rod guard to the diff, you can pop the center link out and rotate the end of the center link to increase or decrease length. Then careful manipulation (with appropriate four letter words) of the bottle jack height will allow the center link to be reinstalled. It is a pain.
Chris
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From: Rick Larson[SMTP:rlarson@dsldesigns.com]
Sent: Thursday, March 16, 2000 11:43 PM
Subject: Re: [D90] SG stage 3 bits
Jamie Austin asks:
>Does anyone run a SG stage 3 suspension kit?
>Did you have to change the prop shafts for ones
>with longer sliding joints in then to allow for the
>extra axle travel? or did you need ones with double
>UJ's in them to allow for the extra 'lift' the suspension kit gave?
>I just had a brainwave that sent my credit card shivering on the
>corner of the room....when I buy my SG stage 3 kit, will I need a
>pair of new prop shafts??
The extra length required of the prop shafts due to the lift is small. Your stock
shafts are probably long enough. Due to the way the LR radius arms work the prop
shaft really doesn't go through a large change in length. It rotates with the the
radius arms as the suspension drops. The real problem is the angles the u-joints
experience will be increased significantly. Unfortunately U-Joints aren't balanced
at angles greater than 10-14 degrees (angles from memory). People and LR's seem
to have various tolerances with regard to the vibration from unbalanced U-Joints in the
drive shafts. The idea behind the a drive shaft with double U-Joints on one end
is that each U-Joint at that end experiences roughly half the angle. It is more
likely to run smooth. However with the two U-joints at one end, the third U-Joint
at the other end is unbalanced. So you really want to minimize the angle it sees.
This is done by tilting the diff up a bit. Fortunately stock LR's are built with
tilted diffs. (No one has explained to me why yet.) But in some cases people,
myself included, have had to put some amount of effort into tilting their diff
a bit more. I put in a extension piece into the upper A arm on my D90 to further
tilt the rear diff up. It is worth trying the Stage 3 kit on your LR and seeing
what happens. If you get driveshaft vibration go to the double U-jointed shafts.
If that doesn't help as much as you would like work on tilting the diff. Classic
symptom of driveshaft vibration is that around 40-50 mph you get vibration when
you let up on the gas. Unless you have severe problems it doesn't occur
under acceleration or at low speeds.
As usual, time and money can solve the problem........
-Rick