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  #1  
Old September 27th, 2007, 05:43 PM
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steve
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wobble mystery

So here is my wobble mystery on the 110.. any ideas would be greatly appreciated:

The wobble occurs inconstantly. Most often while turning @ ~45-60mph and breaking at the same time (either direction). The wobble feels like a front wheel is hopping… seriously, once it starts it progresses quickly (10-20 seconds) until I can barley keep her on the road (death wobbleish). I do get some oscillation while coming to a stop, but it does not happen all the time. At first I thought it was the rotors and if I cant narrow it down I will replace them next but they are not that old and it does not oscillate at every stop like a warped rotor would (right?). Plus, it will sometimes wobble around turns without breaking although not as bad, breaking defiantly exacerbates the symptoms. The most odd thing is that she drives fine 95% of the time and at 75+, smooth and tight.

This is what I have replaced recently:
All wheel bearings,
All seals in the front hubs
Rear stub axles (odd wearing from incorrect bearing preload…ex-mod sals.)
New rubber bushings in the rear (new hardware)
Blue poly bushings on the front radius arms (slowly going back to LR rubber)
New rubber pan hard bushings (Welded plate to fix warn holes and new hardware)
New steering box and ball joints all around.
Recent alignment.
Adjusted preload on swivel pins via fish scale method.
Tires have never liked to stay balanced but they aren’t that bad.

Here is one of my questions. If I mixed up the swivel bearings while reassembling the front hubs could that cause a serious problem? Also, if my scale was not correct and I removed to many shims could incorrect preload on the swivels cause this?

Any help would be great… looking for ideas to investigate before I keep replacing things and hoping.

Cheers
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  #2  
Old September 27th, 2007, 05:56 PM
dnp
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David
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My first thought is that your steering damper is shot. Try replacing that first. Also, certain tires can do some really strange things.

If you have a death wobble situation, it's generally due to some type of un-damped oscillation. I would try the steering damper (stabilizer) first
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  #3  
Old September 27th, 2007, 08:53 PM
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steve
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Worth checking, thanks for the advice. Although mine is less than a year old, I will check and see mabye I got a dud.

I thought the steering damper should essentially do nothing on paved roads if everything else is AOK...is that right??

I have been wondering about the tires as well, I'm runnig cooper ST-C currently and I would never buy a set again. Last trip to baja I had 3 flats... Is it possible for tires to cause this type of wobble? There are no flat spots, they never stay balanced long... but the wobble is severe.

I like you damper theory, I have been hoping the answer is staring me in the face...ill let you know.
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  #4  
Old September 27th, 2007, 09:15 PM
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Kevin Buckley
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Damper is definitely NOT your problem. You should be able to go with out one and not notice hardly.
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  #5  
Old September 27th, 2007, 09:32 PM
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steve
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Quote:
Originally Posted by KevinNY
Damper is definitely NOT your problem. You should be able to go with out one and not notice hardly.

Thats what I thought too.
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  #6  
Old September 27th, 2007, 09:52 PM
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Scott
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I had that issue a few years back... The nuts on my control arms were loose, where it attaches to the frame. You may want to check them.
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  #7  
Old September 27th, 2007, 10:05 PM
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steve
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Quote:
Originally Posted by woldd90
I had that issue a few years back... The nuts on my control arms were loose, where it attaches to the frame. You may want to check them.
Thanks,
That has happend to me too, except they were the front nuts on the axle side. I went under last week and gave everything a good snugging....I'll check again though...that was my plan tonight If I ever leave the office
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  #8  
Old September 28th, 2007, 10:53 AM
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David
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Quote:
Originally Posted by KevinNY
Damper is definitely NOT your problem. You should be able to go with out one and not notice hardly.
By no stretch of the imagination do I claim to know everything about steering systems, but it seems to me your rationale suggests that there really was no real reason for Rover to put a steering damper on these trucks to begin with. By its very nature, this is what a steering damper is supposed to do: dampen oscillations. If it's supposed to do something else, what is it?......I've had several trucks (other than Defenders) with wobbles that fit this exact description, and replacing the damper has cured EVERY one of them)

(BTW: I'm not trying to provoke an argument. I'm just saying that if the damper's not intended to help stop wobbles / oscillations, what IS its purpose?)
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  #9  
Old September 28th, 2007, 10:56 AM
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Kevin Buckley
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Dampen the snap back of the wheel that can occur off road.
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  #10  
Old September 28th, 2007, 11:00 AM
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Quote:
Originally Posted by KevinNY
Dampen the snap back of the wheel that can occur off road.
I respectfully disagree. There may be a certain additional benefit in that situation, but I do not believe that is the primary reason for the engineers designing a steering damper on these (or any) trucks.
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  #11  
Old September 28th, 2007, 02:06 PM
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Kevin Buckley
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series trucks don't have one.
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  #12  
Old September 29th, 2007, 01:12 PM
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steve
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glad I sparked debate...

anyhoo. I went though everything last night, nothing was loose except where the trailing arms connect to the rear axle needed a bit of snugging. The wobble is still present although I have been afraid to try to get it to progress to death wobble.

I also added a half a degree of toe in, just because...and nothing.

I guess I'm going to have to tear down the front again and see what is going on. I'm also going to check the preload on the swivels with a better scale.

What is the best method to check the swivel bearings? just look for play and obvious wear?

What are the chances this is a tire problem? I don't currently have another set to change out...will 3 do?

Cheers
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  #13  
Old September 30th, 2007, 03:24 AM
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Steve - To check the effect of tires, how about swapping front-to-back? This will tell you if you have a particular tire that's bad, but not if all of the tires are bad (or good).

Regarding the swivel pin preload, in all honesty, I set mine by feel. I don't promote this though because it's subjective. The fish scale is the best objective method if done properly. But for a sanity check, you should check for looseness by hand after you set it just to double-check. I make sure I don't feel any play or excessive drag. Similarly, it might be a good idea to check your wheel bearings. I'd also still check for looseness along the entire steering path - steering box, drag link TRE's, and tierod TRE's - even though you've replaced a lot of these parts. And make absolutely sure there isn't excessive movement in the panhard rod - the most common culprit for death wobbles. I know you've replaced the bushings and repaired worn holes, but sometimes inadequate fastener torque will allow motion as well.

BTW, just went back and read your question about mixing up the swivel bearings. It's always best to keep them matched as they develop wear patterns. You might see faster wear with mismatched wear patterns. So it would be a good idea to re-check the preload periodically. If you find that you're losing preload prematurely, I would replace the bearings rather just remove shims. It's a sign of accelerated wear and potential bearing failure. Also, it's a good idea to keep new bearings in matched sets as well.
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  #14  
Old September 30th, 2007, 12:09 PM
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Hey steve, it sounds like you have covered your bases. Just one thought, did you recess the hub seals inside hub lip 4mm? I know some friends of mine didnt and got a false torque reading on the hub nuts. Good luck JP
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  #15  
Old September 30th, 2007, 12:49 PM
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Quote:
Originally Posted by Ryan Sakurada
It's always best to keep them matched as they develop wear patterns. You might see faster wear with mismatched wear patterns. So it would be a good idea to re-check the preload periodically. If you find that you're losing preload prematurely, I would replace the bearings rather just remove shims. It's a sign of accelerated wear and potential bearing failure. Also, it's a good idea to keep new bearings in matched sets as well.
Ryan- Thanks for the reply.
I know to keep the bearings matched, there was just a mix up on one wheel. I checked all the ball joints. All kinda new all tight.

I think I'm going to try to find a set of tires to swap out. I tried the switch around and even tried to swap the spare all around with no luck. If that dosn't do I'll it tear down the front hubs and check it out.

If the actual swivel pins are worn I would feel play right?

Cheers
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  #16  
Old September 30th, 2007, 12:52 PM
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a bit of a side track here, but related.. Years ago I got a call from the dealer who was doing some work on the truck.. (forgot what) Anyway they said during the test drive they found some sort of wobble around turns and asked me if I had done any serious off-roading becasue they felt that the issue might be a bent frame (!) Yeah they said that. I said no, nothing that serious, let me come in and go for a test ride. So I get there and we take off down the highway for a mile, get off an exit ramp and as we're going around theres is this wobbly, shifty feeling, with a clanking to boot. We pull into a parking lot and take a look around the truck. Well whaddya know the tech didn't tighten the lug nuts on one of the back wheels!! literally not even finger tight. Tightened them up right there and the bent frame "problem" was gone.. bent frame - yeah. They're lucky the wheel didnt come off on the highway..

check tire pressures!
steering box preload!?

good luck..

~Steve
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  #17  
Old September 30th, 2007, 05:24 PM
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Quote:
Originally Posted by revorder
Hey steve, it sounds like you have covered your bases. Just one thought, did you recess the hub seals inside hub lip 4mm? I know some friends of mine didnt and got a false torque reading on the hub nuts. Good luck JP

That's a good thought. Definitely something that can be missed if you're not aware of it.
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  #18  
Old October 1st, 2007, 05:36 AM
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Dave Haynes
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You did set the swivel preload with no swivel seals fitted, right? (or adjust to a high than book setting).
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  #19  
Old October 2nd, 2007, 12:38 AM
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Quote:
Originally Posted by epninety
You did set the swivel preload with no swivel seals fitted, right? (or adjust to a high than book setting).
No i did it with the seals in . I did do it higher than book, but how much higher do you think?

Cheers
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  #20  
Old October 2nd, 2007, 05:49 AM
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Dave Haynes
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TBH I don't know, I've never had much luck setting by spring balance. There's just too many variables. Depending how the vehicle/axle is supported, gravity tries to assist in one direction, not in the other... I just never managed to get a consistent reading, so I have always set by feel. After ten years and four land rovers I realised I always was setting too loose... and I was always near to the point where wobble sets in.

As long as it doesn't affect the self centreing action, setting a bit too tight shouldn't cause any problems. If you still have a thin shim on each side, I would pull one from each side and see what the effect is. Once you've done it a couple of times it doesn't take too long to do, and all the bolts are already clean and freed off.

I'm not convinced what you have is death wobble though. You said it felt like one wheel was hopping? I'd not put that description onto what I know as DW. Are you sure your CVs are good? What about the phos. bronze bush in the drive flange. I was discussing that causing odd 'wobble' symptoms with the current owner of my old Disco the other day (which now has 200k+ on it).
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