dhp123166 Posted June 29, 2008 Share Posted June 29, 2008 Right at about 40 mph I have this insane wheel shimmy and above and below that it pretty much disappears. The steering rack components have been gone over and they are nice and tight. The axle bearings were just repacked and they are fine. My wheels are balanced, and I just replaced the old tension rod bushings. If anything this has made the problem worse. What could it be?? Quote Link to comment Share on other sites More sharing options...
johnc Posted June 29, 2008 Share Posted June 29, 2008 Tie rod ends, steering rack bushings, steering coupler, wheel bearings, front end alignment. Check all of those. Quote Link to comment Share on other sites More sharing options...
dhp123166 Posted June 29, 2008 Author Share Posted June 29, 2008 I could have sworn I wrote that the steering rack components and bearings are fine. The steering coupler is fine, and so is the alignment... Quote Link to comment Share on other sites More sharing options...
woldson Posted June 29, 2008 Share Posted June 29, 2008 Stay off the rumble strip! Quote Link to comment Share on other sites More sharing options...
91_4x4runner Posted June 29, 2008 Share Posted June 29, 2008 I had that exact problem with my 4Runner. Turned out that the spindle nuts weren't properly torqued. Quote Link to comment Share on other sites More sharing options...
Lt. Cdr. Tom Dodge Posted June 29, 2008 Share Posted June 29, 2008 I could have sworn I wrote that the steering rack components and bearings are fine. The steering coupler is fine, and so is the alignment... In wanting to help you, could you give us the specifics of what "fine" means in your diagnosing of those parts? johnc and everyone else are just trying to help and sometimes one persons definition of, "checked and are fine" could mean some aspect of those components could have inadvertantly been overlooked. In this case, being as you listed petty much all of the possble components typical of the issue you described, we can only assume something was overlooked or the issue didn't reveal itself due to the techniques used in "checking those components. I.e. it is common for a ball joint to be misdiagnosed due to "how" it was checked. In short, with more specifics, this forums collective efforts can be more effeciently utilized. Quote Link to comment Share on other sites More sharing options...
johnc Posted June 29, 2008 Share Posted June 29, 2008 I could have sworn I wrote that the steering rack components and bearings are fine. The steering coupler is fine, and so is the alignment... Everything's fine I guess. Good luck. Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 29, 2008 Share Posted June 29, 2008 Had a persistent problem with my wife's 260Z where the car was jumped and crash damaged. I had replaced all front end components yet had a persistent problem with shimmy. Pulling my hair out for over 10,000 miles. When I replaced the tires, the problem went away. Even when everything is 'fine' a set of tires that is out-of-round can cause FITS. Normally it gets better swapping front to back to check...but if you (like I did) have FOUR of the wobbly wonders, you will NEVER figure it out till you swap wheels and tires with a known good set. This was so common in the old days, Ford would replace problem customer's tires with Michelins (Instead of the company supplied Firestones) as their track record for making tires that are actually ROUND (what a concept) was unrivaled at the time (late 70's early part of the 80's). So if everything REALLY is 'fine' then change your tires and rims and see if that does it. BALANCING only fixes dynamic imbalance and static imbalance. If you have a tire that IS NOT ROUND you can balance it all you want and you will shake like crazy no matter what you do. Just a thought... Quote Link to comment Share on other sites More sharing options...
dhp123166 Posted June 30, 2008 Author Share Posted June 30, 2008 By everything being "fine", I mean that a mechanic went over it and he found nothing of a problem enough to charge me for... So everything really is just "fine"... One thing I did neglect to mention is that I am running wider rims. They are balanced as I know enough to get that fixed at the first sign of a problem. The tires are new as well. There is something wrong because I have run it in its' current set up with no shimmy before. My current thinking is that it is something really esoteric, i.e. once in a lifetime replacement like the harmonic balancer... According to the service manual it could be something in the steering box... Quote Link to comment Share on other sites More sharing options...
dhp123166 Posted June 30, 2008 Author Share Posted June 30, 2008 It seems like there is too much play in the pinion. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted June 30, 2008 Administrators Share Posted June 30, 2008 Harmonic damper being out of balance or separated, would not shake the car like out of balance tires. You would feel a slight buzz, and that buzziness could be strongest at specific "engine" RPMS, regardless of the gear chosen and/or vehicle speed. Vibrations that are specific to vehicle speed, regardless of engine RPM or gear chosen would be chassis issue, not engine or transmission related. Regarding the tire balancing. Did the tire shop balance them dynamically or statically? If they balanced them statically, (weights only on the inside of the wheel, usually for cosmetic reasons and is a little quicker to perform), the wheels WILL still be out balance dynamically and will shake the steering wheel. In the distant past, whenever I had wheels “static only” balanced, the tires would still shake the car. Then I learned of dynamic balance and how it is important, especially with wider wheels, and now I makes sure ALL of my wheels are dynamically balanced, regardless. A dynamic balance will have wheel weight on the outside and inside of the wheel, which balances the wheel statically, AND dynamically, eliminating couple/rocking forces, (the wider the wheel, bigger issue this becomes). Dynamic vs static balancing… http://www.gsp9700.com/pub/features/intro.cfm Chassis Vibration diagnoses… http://www.yokohamatire.com/pdf/tsb-TireBalance-12803.pdf Quote Link to comment Share on other sites More sharing options...
dhp123166 Posted June 30, 2008 Author Share Posted June 30, 2008 I was using harmonic balancer as an example meaning that these Z's seem to be so well engineered that some things that fail after thirty years can cause alot of trouble and they can be such an easy repair. I will definitely research the tire balancing more as I have free balancing. The pinion seems to have over .3 mm of play which is what the service manual recommends as a cut off point. I measured this with a cursory twist though, seemed to be awful loose, how much play should there be??? Should I be able to move the pinion with my hand while the car is stationary on the ground??? Quote Link to comment Share on other sites More sharing options...
dhp123166 Posted June 30, 2008 Author Share Posted June 30, 2008 So I went over to the tire shop where I had purchased my tires and asked them to dynamically balance them. This was the shop that originally supposedly balanced them. But then I do not remember seeing any sticky weights on the front of the rim like had been done in the past. Free of charge. Problem solved. Another great thing about my Z: 80 % of the time when I am thinking it is something dire and obscurely wrong, it is usually something much simpler. Thanks again for clarifying with words and diagrams the different kinds of wheel balancing... Quote Link to comment Share on other sites More sharing options...
johnc Posted June 30, 2008 Share Posted June 30, 2008 I guess everything wasn't fine. Quote Link to comment Share on other sites More sharing options...
dhp123166 Posted June 30, 2008 Author Share Posted June 30, 2008 Hey, I was just going by what someone else told me. Someone I paid for goods and services. Which leads me to my fun little quote at the end of my post: "Just because I pay someone to do a job, it doesn't necessarily mean that they know what they are doing..." Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 30, 2008 Share Posted June 30, 2008 With over 35 years in engineering & manufacturing one thing I've learned. If is WAS fine and now it is not - then what has happened since then? Usually a good place to start looking. I've also found with the Z that common sense and knowing the car goes a long way when discussing a problem with a professional. Just because they get paid to fix a problem doesn't always mean that they understand the dynamics of a Z better than you do - or should. Quote Link to comment Share on other sites More sharing options...
Tony D Posted June 30, 2008 Share Posted June 30, 2008 One quick thing to learn is not to flippantly retort when someone makes a suggestion... Things that were 'fine' were not. Which is why JC posted what he did... Having someone else check them doesn't mean they're right. I have literally flown thousands of miles because a customer wants someone else to look at something. Even though the guys that have been taking care of them are competent, knowledgable, and generally well-versed in what they do...looking at the same problem after you missed something 'insignificant' the first time heightens the possibility you will overlook it the second time the same set of eyes looks it over. More eyes means more different points of view. Many times, guys will say "Damn, how did I miss THAT? I looked at it X times over the last month and it never occurred to me that it was bad! Looked good." When in dobut, go back to the basics and start at square one... Which is what JC had suggested. Someone missed something. Quote Link to comment Share on other sites More sharing options...
dhp123166 Posted July 1, 2008 Author Share Posted July 1, 2008 I make it a point not to get argumentative with anyone online because; Arguing online is like two retards running a competitive race, One may win but he is still retarded... Quote Link to comment Share on other sites More sharing options...
woldson Posted July 1, 2008 Share Posted July 1, 2008 When someone of great statute gives wisdom to a void, you have to wonder why he bothers. This site dose not bother with the maundaune as you infer. Quote Link to comment Share on other sites More sharing options...
dhp123166 Posted July 1, 2008 Author Share Posted July 1, 2008 Do you mean "mundane"? Quote Link to comment Share on other sites More sharing options...
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