I've always had some shake in the steering on my 97 NAS D90, but I figured this was normal for a heavy single axle truck. Over the last 6 months tho, it's gotten really bad. On pretty much any terrain, if I'm 10 degrees to the right of dead center on the steering wheel, I get a violent shake (even oscilation between left and right, not veering out of control) that will go away if I steer far right or left. This also gets triggered by bumps in the road (manholes, potholes, etc) if I'm going straight on a flat road.
I had the wheels rebalanced TWICE and that only seemed to exacerbate the problem. The second time was at Land Rover of Nashville, after they INSISTED this was the problem and not anything to do with the steering or suspension. Even though I ASKED them to check the linkages for wear or tolerance. That will probably be the last time I take it there for any kind of service. (this and the fact that they charged me $1K to replace the fuel pump).
There are three bars that run parallel to the axle. I checked all three and they seemed to be in good shape with tightened fastners, however, I can rotate each bar front to back about 20 degrees to 40 degrees depending on the bar. I don't know how much play needs to be on each, but this seems excessive and I think might be the root problem. The bushings seem okay, but I didn't disassemble to check intensely.
How much play should be in the bars? What else should I check? And to releive play, do I just need to tighten fasteners? Any other tips? This will likely be my holiday weekend project.
yeah, you gotta check whats up, there are many things that could cause this. . .
The common culprits are: steering damper, panhard rod bushings, tie rod ends, swivel preload, steering box adjustment. jack your front end up (get the tires off the ground and you can really pull on things to check for obvious slack)
"Yeah, make sure its a flatbed...."
Thanks for the tips guys. I did do searches on Death Wobble and read through those. I don't think it's the steering damper (less than two years old OME unit) or the swivel preload, although those are things I will check. I really think it's the bushings or the bolts connecting the rods to their various linkages. Is there a guide that gives me torque settings and an estimate of play in the bushings to determine if they're in spec? Truck has 107K miles on it.
Just to update this thread, I figured out what the problem was and applied a temporary fix.
I've heard that the ends of the panhard bar can get worn and start to wobble. That's exactly what happened to mine. The holes in the brackets on the axle and the pitman arm are a little worn from the bolts shaking around, but not too badly. The bolts were fairly fatigued and a lot of the threads had been filed down on them. I replaced them with some new grade 8's and locking nuts, tightened em up, and that seems to have done the trick.
My long term concern is that I can't tell if the internal fittings on the ends of the bar need to be replaced, and is this just a vice press job or are they forged inside the arm? At some point, I'm sure the new bolts will suffer the same fate as the old bolts and it'll start to wiggle again. I'm looking for a long term fix. Any thoughts?
Also, would like to know if these may fit (two on right). Nice for drag link and tie rod upgrade as well. You would need to drill out the holes for the bolts to a larger size to match the new bolts.....http://www.bulletproofsteering.com/trackbar.html
I prefer the look of the latter one as it eliminates the bushings. The link above references the "death shake" and explains it a bit.
I meant to include pics with my original post but was running short on time. Thanks nikojo for the links. The equipe solution is interesting, and I actually thought about putting some washers in between the brackets to try and easy the load on the bushings and put more on the bolt, but I wasn't quite sure what part was causing the stress and I didn't want to put too much stress on the brackets by shimming washers in there.
The long term problem here is that as time goes on, the wearing will gore out the bracket holes and a larger and larger bolt will be needed to fill it. As it is, the grade 8's I replaced the OEM's with were about .02 bigger in circumference than the OEM's. They were very snug, but still got em in there.
This seems to be a common problem. Any thoughts on long term fixes?
The problem is the bushing is worn out and then the excessive play goes to the bolts and the chassis mount. You can replace the bushing. Using a socket of similar size to the bushing housing you can pound it out and pound in a new one. Problem is this will happen again but not for a while.
Other option is replace with the Equipe version which is nice but you will still have to deal with bushing issue.
I like the "BulletProof" solution as it gets rid of bushings altogether and it actually has play front/back in addition to side/side (better than bushing). In your particular case it is nice as you can "drill up" your mounting hole to match the bolt used in their system. Seems like very heavy dut upgrade and low maintenance (no bushings, no ball joints, etc). Also, is "bolt in" other than the drilling you may have to do. I have spoken to the owner/manager and he is very helpful/informative.
Land Rover Nashville does good work, if you cant do it yourself. Kelly Graham who also works there has alot of defender knowledge (best4x4 on board) Need to ask for Mark Fletcher to do your the work on your D90. He has always been fair to me. Some of the others have not though. Mark is a defender fanatic. There is also the new shop in Franklin that is owned by two of LRN ex master mechanics heard they charge whole lot less but have never used them.
94 D90 ST Arles Blue
94 D90 ST White
02 Disco II
I have to call bullshit on LRN. There are definitely quality people working there, and I have personal relationships with some of them, but the overall experience is very poor. I can NEVER leave there without spending $800+ and when I get my truck back, there's always something ELSE wrong with it. See my original post in this thread for a good example - they didn't diagnose the panhard problem and instead gave me a wheel alignment and called it a day. And gave me the pleasure of paying for it, even though it didn't solve my problem. This was after I begged them to NOT do that, as I had just had a wheel alignment <30 days prior. If I had a lift and unlimited time, I'd do all my work myself, but in a pinch, I'm more likely to use someone like Ed's Rover (in Franklin) instead of LRN.