Wobble over 40 mph

[SMOB]

Just got new tires, new QT drag link/HD track rod/connectors. The truck needed an alignment bad AND gave me a death swerve (both directions back and forth) over 40 mph. Got the 4-wheel alignment done today, but still have the swerve over 40 mph. Not pretty. I put on the drag link and track rod. Steering damper replaced a couple months ago.

Any idea what this might be? Worn bushing somewhere? Drag link need some turning? Note that it drove fine before tires/DL/TR swap.

[bjf]

I had it with my new tires over 50. The tires needed to be rebalanced.

[evilfij]

Panhard rod bushings, rear ball joint, ball wheel bearing, unbalanced tire etc.

[SMOB]

Panhard rod bushings, rear ball joint, ball wheel bearing, unbalanced tire etc.

True, I'll check those other (non-tire) things tomorrow - but before the installations, I had no problems. Would installing a crossrod eye, drag link, etc etc make something else worse? Or just make it more apparent?

[mikeslandrover]

Just got new tires, new QT drag link/HD track rod/connectors. The truck needed an alignment bad AND gave me a death swerve (both directions back and forth) over 40 mph. Got the 4-wheel alignment done today, but still have the swerve over 40 mph. Not pretty. I put on the drag link and track rod. Steering damper replaced a couple months ago.

Any idea what this might be? Worn bushing somewhere? Drag link need some turning? Note that it drove fine before tires/DL/TR swap.

Does it swerve under braking or all by itself?
I'd check all the suspension bushes and bolts for wear and tightness.
I had a death swerve once associated with the rear radius arms falling off. The M20 nuts had slackened off and allowed a considerable amount of read axle steer :eek:

[woldd90]

I would check your the nuts on the front control arms and rear trailing arms. I had the same problem, and the nuts were to blame.

[Gren_T]

Hi Steve,
is it worse under acceleration or when coasting? check the easy things first, are all suspension & steering bolts up to torque, are the wheel nuts loose?
check the tyre pressure & balance, one other thing to consider is the swivel housing bearing in the hubs, they should have equal amount of tension on them to mantain a true run on the tyre.
if one has play then the result will cause the steering to wobble and possibly lead to the need to keep correcting the steering, it would have to be quite bad to do this and i would have thought you'd have felt it before unless your TRE's were sized.

to check preload remove the TRE's from both hubs and turn the tyrel lock to lock they should be equal, check with a spring balance and wheels removed for accuracy.

landys may be bad for the pocket & the planet but are fantastic for keeping the brain exercised.

have fun

Gren

[SMOB]

Hi Steve,
is it worse under acceleration or when coasting? check the easy things first, are all suspension & steering bolts up to torque, are the wheel nuts loose?
check the tyre pressure & balance, one other thing to consider is the swivel housing bearing in the hubs, they should have equal amount of tension on them to mantain a true run on the tyre.
if one has play then the result will cause the steering to wobble and possibly lead to the need to keep correcting the steering, it would have to be quite bad to do this and i would have thought you'd have felt it before unless your TRE's were sized.

to check preload remove the TRE's from both hubs and turn the tyrel lock to lock they should be equal, check with a spring balance and wheels removed for accuracy.

landys may be bad for the pocket & the planet but are fantastic for keeping the brain exercised.

have fun

Gren
It occurs during acceleration, coasting and braking over 40 MPH. Less than 40, it's great. I checked the DL, TR, panhard bar/nuts/bushing/connectors. All solid. Messed with the front control and rear trailing arms, all solid. I was thinking that it's the spring bushings, front or rear wheel bearings, or tires. But recently had the springs and shocks replaced, so it's probably not that. Also had the front wheel bearings redone within the last 90 days. Probably not that. Will check the rear later today.

So either something failed in between the tires and DL/TR installation, or the tires are unbalanced. Maybe I just need to jack it up and see if a tire is loose. Weirder things have happened.

Thanks for all the feedback.

[JSBriggs]

Swivel ball preload.

Everything else has a multiplying effect on the wobble, but swivel ball preload is usually the cause.

-Jeff

[SMOB]

Swivel ball preload.

Everything else has a multiplying effect on the wobble, but swivel ball preload is usually the cause.

-Jeff

So, I figured it out - the Equipe HD track rod was scraping up against the inside of the Safarigard TR guard (installed by PO). I adjusted the position of the guard so that the TR was centered and tightened the bolts. And it drove perfectly over 40 MPH. It was user install error, but hey, I know about 5x more about steering issues than I did before. Don't ask why I have both an HD rod and guard. Thanks to all those who gave me advice.