------------------------------
Date: Wed, 21 Apr 1999 14:45:54 -0800
From: "Tom Walsh" tomw@best.com
Subject: Re: [D90] GKN torque limiters
> >I hear the Ashcrofts have a clutch assembly that goes on the hub which is
> >set to slip (not break) before an axle component fails. Rumor has it that
> >Chris Hinkle has some. I guess Warn also has a similar setup, but not for
> >Rovers. Not an uncommon gizmo on desert racers. Sounds like a great idea to
> >me (having busted a front CV and shaft)
> >
> >Dennis White
>
> Tom Walsh has the GKN torque limiting hubs on his Disco -- is that
> what you're thinking of? He lurks on this list occasionally; maybe
> he'll speak up with his experiences.
to be specific
I'll be wheeling in the rig on and off in about two months or so (
maybe less )
I have used it at the Nevada trophy rally, and it performed well...
Hard to tell if they stopped something from breaking....
The rig took a beating, did some decent wheeling, no broken axles!
I did have my stub axle bolts mysterioulsy loosen up after leaving my
vehicle unattended???.... this caused a huge vibration ( and could have
killed us )... but didn't take out the CV... the vibration killed the
rest of my exhaust Y pipe... Exhaust has been rebuilt.. but before I
wheel I want to inspect the front axles, replace the bolts, and fix a
rear hub leaking seal at least... I have my hands full with a full
build up and restore of a series which is almost done... Then onto
the coiler beast!
TomW
------------------------------
Date: Wed, 21 Apr 1999 15:56:34 -0600
From: Jeff Gauvin jeff.gauvin@lsil.com
Subject: [D90] Torque limiting hubs
>Man, that would just be weird. It would take some getting used to--giving
>it gas and having stuff spin but not move the tires (in extreme situations)
>I would keep thinking my clutch had gone out. That would be unnerving. I
>wonder how often they slip on an extreme trail with lots of grip like Moab.
>
>Am I understanding how they work right?
This is all second hand info, but my understanding is that even
when they are slipping, some torque is still transmitted to the
wheels. So if you are wedged in something real good, yes it would
seem like your clutch is slipping (a clutch *IS* slipping), but if
you are just powering through some mud or up a rocky slope, you
may not even notice -- well, maybe your engine would race slightly.
Dunno.
The theory is that they are not supposed to slip until you've reached
the limit of what your axles/CVs can handle, so I guess the occasional
unnerving sensation is better than a loud *BANG*. I wonder how much you
can "use" them before the clutches get glazed and start to slip all
the time?
Tom wrote earlier that the large hub requires the larger hole of steel
wheels -- it won't fit alloys. He also wrote something about having to
replace the rear axles with ones w/o an integrated drive flange. Is this
a Disco thing, or do D90 axles have integrated drive flanges? Maxi-Drive-
Engineering (Australia) makes a cool looking drive flange with a screw
on cap. Bust an axle? Just unscrew the cap and pull it out! OTOH -- those
that need this time saver may have other problems... :-)
Jeff Gauvin
'94 D90
------------------------------
Date: Wed, 21 Apr 1999 17:36:34 -0800
From: "Tom Walsh" tomw@best.com
Subject: RE: [D90] torque limiting device
>They don't slip 100% they just slip all the excess torque...
> Thats why its hard to tell if they are doing anything!!! I bet I could
> get out and touch em after a work out and they should probably be
> hot! Just haven't had enough time on em to qualify it yet
>
> TomW>>
>
> Could you paint some reference dots on the hub/device and on the wheel
> itself?
Very good!... I'd have to open it up and put the dot on the inside (
no real biggy )... but that would show it ( unless they keep slipping
360 degrees :)
> I'm guessing (from looking at a photo of it) that it replaces the
> drive flanges on the outside of the hub (outer end of the halfshaft)?
Yes it replaces the drive flanges... I have a Disco, It uses the one
piece axle and flange.... Before I did the torque limiters I had
upgraded to ashcroft HD axles... these were two piece ( axle and
separate flange )..... I think the D90 comes with a two piece
setup???... So in essence you need 2 piece axles ( err.... not a
broken Disco axle... thats two pieces :)
The fronts on the Disco ( and Defender ) are two piece stock so no
biggy there...
The only problem I've seen with em so far is:
The stock flange has a small paper seal , sealing it to the hub....
the torque limiters end cap screws on and does not seal oild
perfectly ( for me ) .... so .... this hi-lights an inner axle seal
failure ( very common and no biggy if it lets 90 wght get to the
outer wheel bearing assy )... but with the torque limiter the 90 wght
drips out of the end cap... so you gotta fix the pesky inner seal (
where as you could wing it for a while with the stock setup )
kind of a minor knit, but I gotta spend a few hours dealing with them
one of these days.. Or I leave a trail of 90 wght where ever I go (
bigger than the usual one :)
also... fitment to the hub was a bit pesky ( weirdo allen bolts, that
thread sorta buggary , again pretty minor anoyance compared to
yanking a front halfshaft at night in a cold rain in a mud bog! )
TomW
95 LR Disco "The Light Brigade",
73 Series III 88"
--------------
From: Tom Walsh
Date: Fri Nov 17, 2000 1:15am
Subject: torque limiter info ( no more broken axles )
I finally got this part of the web site up ( 1st pass )
http://www.fluentnet.com/lr/tech/torque.html
TomW
----------
From: alan_ottley@3com.com[SMTP:alan_ottley@3com.com]
Sent: Monday, February 28, 2000 10:32 AM
Subject: Re: [D90] wheel bearings are squeaking!!
>I was in a couple feet of water about a week ago, and I asked what
>fluids/grease I should replace.........Well, today I noticed a squeaking noise
>coming from what I think is the bearings......So, what exactly should I look at?
Ehren,
It's not too difficult to get in there and inspect them. If you need to repack,
have fun, and if you need to replace the bearings and races, here's the scoop:
Timken Bearing numbers
The numbers on the bearings are 603049 and 603011.
The bearing and race can be purchased as a set.
The Timken No. is Set 37, and cost about 10 bucks.
A.
----------
From: David Gomes [david.gomes@us.gambro.com]
Sent: Thursday, July 27, 2000 10:35 AM
Subject: RE: [D90]Improved hub seals (was brakes, and now wheel bearings
"....but often times it can be frozen to the hub....."
Careful of mixing terms here. When you go after that inner bearing, it's
outer race will be pressed into the inboard face of the HUB. You will
indeed have to drift out that outer race, just like you should have to do
for the outer race of the outer bearing (which you'll find pressed into the
outboard face of the hub). Use a brass rod and tap around the perimeter of
the race evenly to work it out.
I think what Doug B. refers to is that people have had varying experiences
with the inner race of the inner bearing which you'll find attached to the
stub axle (hollow "tube" shaft bolted to the Swivel Pin Housing, through
which the outer front axle half shaft passes). Some people find that inner
race just slips off the stub axle (like the inner race of the outer bearing
does). Others find the inner race of the inner bearing is press fit to the
stub axle and a real bear to remove.
There are a few things you can try in progressing order of severity.
1- lots of WD-40 and try to grip the race and rotate it back and forth to
see if you can work it loose
2- use a "bearing puller" to get behind the race and pull it off the stub
axle. This is the preferred method, and a good excuse to buy a good tool
that will come in handy in the future. I'll look for a picture on the web
to send you. I don't have one but I should. They're not too expensive, and
another one of those "Right tools for the job" that save lots of
frustration.
3- heat the race with a torch to see if expanding it will break it loose.
Be careful though. Look at the cut-away diagram in the manual to see if
there are any rubber seals nearby that might be damaged by the heating. If
so, skip this step.
4- Strike the inner race with a sharp cold chisel to try and crack it in
two. Take great care not to nick the stub axle.
5- cut the race with a small cutoff wheel in a die grinder or dremel tool.
May be able to use #3 after a bit of cutting. See that bit above about
great care.....
6- Remove the stub axle from the SPH and take it to a machine shop, or good
automotive shop, to have the bearing removed.
Don't let all this scare you. Best bet is to have the bearing puller on
hand. Absolutely no worries then. Easy job. I think Sears has 'em. NAPA
for sure. Lemme send a link.....Just a minute.....
-Dave G.
----------
From: J. Nielsen[SMTP:cnielsen@u.washington.edu]
Sent: Wednesday, August 23, 2000 11:52 AM
Subject: RE: [D90] Changing front wheel bearings...
Well, I successfully finished my wheel bearings last night. Many thanks to
"Farvin" for his detailed description of how to do the job.
[see http://www.d-90.com/tech/index.html under "Front Wheel Bearing Install" - ed.]
I do have a couple other bits of information for those who are looking to
do this in the future.
First off, the big socket you need is a little hard to find and very
expensive if you find it. I ended up renting mine from super rents and it
only cost $4 including the 1" drive ratchet...this bugger was huge! If
working with that tool doesn't make you feel like a real man, nothing
will!
[a cheap version of the socket is available from JC Whitney for about $14 - ed.]
Secondly, when removing the brake caliper... "farvin" recommended that I
should undo the swivel pin retaining bolts to free up the caliper and then
hang it from the frame with a zip-tie. Well that would be nice if it was
that easy, because you would not have to bleed the brakes. BUT...there
always has to be a but...Those retaining bolts must have been put on by
herman the german and one of them is nearly impossible to get to so
instead of buggering up the bolt heads I decided to disconnect the brake
line instead. I first clamped off the rubber brake line so I would only
loose a minimal amount of fluid. This means you will have to bleed your
brakes later but that is not a big deal to me and not a bad idea
anyway...pick your poison. We really need to design a better bracket to
hold the brake line so this is not a problem and proper access can be
acheived to loosen the swivel pin bolts. If you do attempt to remove the
bracket, bend it out of the way first so you can get a wrench on the bolt.
If some of that did not make sense, trust me it will once you get in
there.
As for the bearings...They are commonly available at NAPA for 1/4th the
cost! Ask for a BR-37 bearing set. I think they were $13-$15 each. You
will need four.
I bought the gaskets and inner seals from the dealer. It was recommended
that I use the RTC3511 instead of the FTC4785. Well it seems that the
dealer has superceeded back to the old part number but it is still the new
double lip seal...so mine was under a FTC4785 part number. Who knows! Just
tell them what you want and I am sure they'll give you the right one.
The gasket is supposed to go in dry per the dealer's recommendation...that
is the paper one that goes on the outside of the whole assembly.
As for the washers, I just reused mine. The dealer was out of stock and
they said they reused them anyway. I have always reused them on my other
cars and had no problems.
That is about it...not too bad of a job difficulty wise but it definatley
is a messy one. Lay out some carboard to work on so you don't have to
spend 45 minutes mopping the garage floor. Dont' ask me how I know.
Good luck and feel free to ask me questions while it is still fresh on my
mind,
Chris Nielsen
'95 D-90SW
----------
From: Winn Bearden[SMTP:wbearden@americus.net]
Sent: Tuesday, September 12, 2000 7:48 PM
Subject: RRO: removing and installing races
Here are some tips for removing and installing races.
If a race refuses to come out with a BFH and punch, take your MIG
welder and run a thick bead around the inside. this will actually shrink
the race and it will practically fall out.
Before doing this, however, you need to place your new race in the
freezer for several hours. The welding done on the old race will have
heated up your hub, expanding it ever so slightly. The new frozen race
will be shrunk ever so slightly. If you do it quickly, the new race
will go into place with just a few licks.
Winn Bearden
19XX SIIa/SIII/RR 100" Hybrid
1967 NADA 109" SW (in pieces)
1996 Disco SE7
----------
From: gbrovers@aol.com[SMTP:gbrovers@aol.com]
Sent: Thursday, March 23, 2000 9:14 AM
Subject: Re: RE: [D90] Wheel bearing seals
Dave
The advantage of lubricating your wheel bearings with gear oil is more
than just a convenience. Gear oil is a better lubricant for this application,
wheel bearings will run cooler as a result of less friction (and the gear oil
provides some cooling capacity) and hence will last longer. The disadvantage
of this arrangement is you have a greater possibility of leaks. Land Rover
installed axle case seals in the rear primarily because of warranty issues in
the North America market. Here where Rovers are marketed as "up market"
vehicles and the minimum price for one is $40,000+, Rover found that these
folks don't want drips on their driveways and garages - period!
In Australia where vehicle durability seems to be of a greater concern,
removing the rear axle case seals is standard procedure. On the front another
thing done is to remove the front axle case seal, the inner swivel housing
seal and the outer hub seal so that literally gear oil can flow from one set
of wheel bearings to the other passing through both swivel assemblies and the
diff on the way. To accomplish this effectively you need to overfill the diff
by jacking the vehicle up in the front. Unlike engines and transmissions you
don't create any problems overfilling diffs (within reason!). The other
critically important thing you need to do when you are eliminating axle case
seals is to upgrade inner hub seals. Before Rover eliminated axle case seals
they had either single or double lip hub seals. When they went to grease in
the wheel bearings they down graded the hub seals because it is very easy to
seal in wheel bearing grease - it doesn't go anywhere because it doesn't
flow! The big problem with this arrangement is that these down graded seals
don't seal some things from coming in such as water! In my opinion whether
you eliminate the axle case seals or not you should upgrade the inner hub
seals to prevent the ingress of nasties into your wheel bearings.
On a related subject - swivel housing grease vs gear oil, I haven't seen
a debate in a while on this list about it. Similar to the axle case seal
issue it was introduced as a solution to a warranty problem - leaky swivel
seals and American driveways and garages, but it was actually an improvement,
swivel housing grease is moly-disulfide and you can't get a much better
lubricant for this application. If you don't want to eliminate the axle case
seal but want better wheel bearing lubrication, eliminate the inner swivel
housing and outer hub seal and run your wheel bearings in moly-disulphide.
Again it is extremely important to upgrade the inner hub seal when doing this.
Bill
Great Basin Rovers
From: Bill & Rachel Burke Sent: Friday, March 31, 2000 8:15 AM Subject: Re: Hey
When I was a mechanic for Rocky Mtn. Intl., it was against company policy to use any kind of silicone (RTV) sealant on flanged surfaces, i.e., axles and stub axles. RTV actually allows the axle flange to flex and creates loose bolts and allows small gaps in the sealing surface after a period of time. If you want to use a type of sealant, Loc-tite makes a "flange sealant." It's a red sticky stuff that we used to use for heavy equipment axles.
The paper gaskets are actually cheaper and with a light smear of grease, they work better. Fortunately, at Camp Rover West, a lot of people will get to hear and see the correct way to do this.
There you have it!
Regards,
Bill
----------
From: Alan Dobbs[SMTP:gulfcmt@flash.net]
Sent: Saturday, July 22, 2000 7:44 PM
Subject: RE: [D90] HD shaft flanges
-----Original Message-----
i have the HD shafts and flanges from GBR.
and the nuts that hold the flange come loose once in a while.
of course with locktite, they dont' come off, but they come loose.
has any one on the list have had same problem?
i am thinking this happens because there's some play in there ... between
the nut and the flange hole.
ho chung
If it is the large center cap, I just apply a small amount of Right stuff
sealant in the threads then tighten well with the same socket I use for the
nuts to remove the wheel bearings.
Are you possibly talking about the 5 pieces of 10mm x 30mm hex bolts.
If so GCR will soon be selling custom made high grade blue-coated socket
head cap screws bolts. They are 12.9 grade compared to the stock 10.9.
They will have a nylon patch integrated on the end of the threads, this will
serve in place of lock-tite and can be used several times over.
Also the bolt head will be cross drilled 6 places so a safety wire can be
attached, though it serves no purpose in securing the bolt it just keep them
from completely coming out.
On the axle splines I bought different size shims to take up the side play
where the snap ring goes also I used loc-tite #480 bearing retainer and it
keeps the shaft from moving in and out of the drive flange.
Alan
Dave Gomes added:
Ho,
Some slack is required there (mounting bold holes) so that any flange will always bolt to any LR
coiler hub, in spite of the stack up of tolerances in both parts as well as
the bolts. It's the clamping force of the bolts holding the flange and hub
surfaces together, and the resulting friction between those surfaces
(ANOTHER REASON NOT TO USE RTV HERE) that really should be transmitting
power from the flange to the hub anyway, not the shear strength of the
bolts.
So, put those things together with the right paper gasket, maybe a tiny bit
of flange sealant, and keep the bolts torqued well, with a little blue
Loctite on the threads. Remember, the tapped holes and the bolts bust both
be oil-free for the Loctite to work. I spray with carb cleaner or
electrical contact cleaner and let dry before assembly.
In the "just to make sure" category you could fit lock wire to the bolt
heads which, if done correctly, will keep them from loosening, but will also
be a (very) minor hassle to work around in a repair. And if it makes you
feel better, bias the flange against the bolts in the forward driving
direction (rotate top of flange toward front of truck) as you snug the
bolts. In reality, due to machining tolerances and things, only one bolt
will really be touching the side of it's hole, no matter how careful you
are, anyway. So, put your faith in the good interface between the flange
and hub surfaces, and keep those bolts torqued.
-Dave G.