Steering vibration, can't find cause.
 

I have the Re-Speed steering rack conversion here, and it was good until recently I redid all the brakes and readjusted and re tightened the steering u-joints, and after that I noticed that when I cross over into 60 mph and up on the freeway, the steering wheel starts to shake quite a bit. Like the kind of shake you get when braking with seriously warped rotors, except I'm not braking.

Now here's the kicker though, the shaking isn't consistent at all. I think depending on the position of my steering wheel, if there's resistance, and how the tires are straddling the lane, the shake may be super severe or completely non-existent at all. Like I can flick the wheel a bit and move around the lane a bit and there will be a sweet spot where it's barely noticeable, and I'll drive like that for a bit and it'll get progressively worse on its own, even though I'm not doing anything different. The vibration is always present when going around the bend or changing lanes. Also up to about 55 mph, everything's pretty damn smooth.

Here are the things I've checked:

Tires - tried 3 different sets, including a brand new one. No change.
Wheels - tried 2 different sets, including a brand new one. No change. Fully balanced and rebalanced.
Alignment - got that checked recently, reads as spot-on.
Bearing play - none that can be found. Everything's tight.
Ball joints are new and don't appear to be loose.
Tie rods are tight, no noticeable play.
Brakes - doesn't seem like there's any binding or warping. When I apply brakes, it has no effect on the severity of the vibration, and when I brake under 60, it's smooth.

Going to check the steering u-joints and suspension bolts, it's the only thing Billy could come up with. Looks like the top one is kind of greasy, like it's leaking or something, probably getting loose from all the shaking. I feel the joints might be binding a bit, because once in a while, when I turn the wheel at a standstill and there's some resistance or ground is uneven, I hear a loud pop.

Other than that, I can't really think of anything. It's as if there's some kind of feedback from the road at 60+, that travels through suspension and puts stress on the binding steering joints and makes it vibrate.

Any ideas? Anyone had this happen?

whisper,
when I get back from my California trip Lets get togather and figure this out. sounds like to me it is just a suspension problem related to the steering rack swap you did. something is not right, we can figure is out, just takes time. I had some issues with vibration before I installed my front air dam, it all went away after that at freeway speed. we will chat next week, pm me on Friday when I get back and we will meet up at your place.

Joe

Could be a failing strut... can get the tire dribbling like a basketball when the road surface makes it vibrate harmonically.

Have a friend in another car drive with you, and look at your tires when you hit the vibration. He may be able to see one actively bouncing more than the other.

Cool, thanks man.

Also, another thing I kind of thought of, maybe it's possible that I need hub-centric rings? Even though I get this vibration with stock wheels... Hmm...

Readjust your wheel bearings or even take them out and have a look at them. You can over tighten them and they will cause vibration when they start to go. They will take the spindles with them if they overheat from being too tight. Ask me how I know.

I was going to say wheel bearing or you lost a wheel weight.

Strange, I have a similar problem, though stock steering... only around 40-50mph on a moderate corner the wheel vibrates.

Defintely re-check the wheel bearing pre-load though.

My car does the exact same thing at about the same speed I was thinking I may have a bent wheel (BBS vert wheels bend easily) or a bad wheel spacer but now I'm not so sure. What alignment specs are you running? I don't know mine at the moment but it has a lot of caster in it maybe that has something to do with it.

Caster will not cause vibration. The stock specs have one wheel angled further than the other to compensate for the crown in the road. Vibration is caused by something that spins being out of balance or worn, or a loose or worn suspension/steering component that is allowing excess play.
If you check the bearings check the races as well to be sure they are in properly.

I took pretty good care making sure the races were sat in flush and the bearing tension wasn't too tight, but I'll check again. Though it seems to me it would wobble if it's too loose rather than too tight, and bearings usually make noise when they're going out - mine are quiet.

I'm thinking too loose.

Any kind of weird wheels you have on there that might not be centering?

I have stockies and Panasports. I'm not sure if I'm supposed to have hub centric rings for Panasports, but I doubt I'd need them for stockies. That'd be silly.

Proper per-spec front bearing pre-load is a lot tighter than most people think.

i second the failing strut. had that problem many, many yrs ago but not on an rx7. i currently have a bad strut on the 7 on the drivers side and it tends to want to quiver at times but not at highway speeds.

Usually if the vibration appears, or worsens, when going around a turn it is ball joint related. I know you said you just replaced them, but I recently went through a bad batch that failed within a few hundred miles. Might be worth a closer look...





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Aight, I'll be looking into all of that stuff. Thanks.

[UPDATE]


This still isn't solved. Still vibrates and I can't figure out what's going on, but I have a new piece to the puzzle and hopefully it might help someone point me in the right direction.

Up until now I've been thinking the vibration is intermittent, it would randomly go away and everything would be fine... Well after a solid test drive today I've noticed that it's not the case. The vibration does not go away - it MIGRATES.

As my steering wheel stopped vibrating for the n'th time and everything was smooth I decided to look down onto the shifter...and what do I see? The shifter is vibrating up and down like some kind of sex machine, as if my whole transmission is going up and down...and at the exact same rate as the steering wheel would vibrate. So at this point I'm guessing as the steering wheel starts vibrating again the shifter will be still, and what do you know?? That's exactly what happens. Steering wheel going mad and the shifter is pretty much still.

I'm still not sure what makes vibration shift from steering to transmission and back, but steering seems to vibrate more frequently when I'm going slightly downhill, and when I'm going slightly uphill, especially accelerating, it goes to the transmission. However for the most part it's so random, it may very well be a coincidence, because I can't replicate it with any amount of consistency.

So what the hell is going on here? Any takers?

Ujoints? Tranny mount?

If I were you I would check the bushings, my car (79 Rx7) at higher speeds it starts to shake as well as turning some times, so this might be something to look at.

Get one of these. Competition Transmission Mount
http://www.racingbeat.com/images/ite...x280/12050.jpg
http://www.racingbeat.com/RX7-1975-1...ate/12050.html

I feel the issue is rotational imbalance somewhere. Since it's speed dependent and not RPM dependent, it must be something that's turning with the wheels, like tires, brake rotors, or driveshaft. Or maybe it's somewhere in the diff or rear axle, but that's too far back to cause steering wheel vibration. Thing is, the car itself isn't vibrating. It's the same sensation as braking with warped front rotors.

I'm trying to think of a link between steering and transmission. They're not directly linked anywhere... The steering rack is bolted to the crossmember, and the crossmember has no play to transmit that much vibration to the engine and tranny to cause the shifter to shake.

Sorry if I missed this in the posts above but have you checked the large nut that holds the strut into the strut housing? I'm talking about the one that would be hidden under the struts dust boot. Only reason I mention is is because one of my came loose earlier this year and caused a hell of a vibration, but only at higher speeds. Might be worth a look.

Did some more troubleshooting. First I put my old front brake rotors on, and it seems like it helped a bit. In fact, I drove the car and was like "Wow it's pretty smooth...did it work?" But there was still a hint of vibration.

So next I did a little test. I marked the front wheels' relation to the rotors, took the wheels off, rotated them 90 degrees and put them on, and took it for a drive. Noted the amount of vibration. Came back, and did the same thing again and again, until the wheels have made full rotations on the rotors.

I think I have something here, because I found a position of the wheels that causes the most vibration and the least vibration. Then I inspected the situation. Free-spinning the front passenger wheel in the air results in the rotor catching a little bit for a quarter of a turn. When the wheel balance weights are on the same side as the sticky rotor section, vibration is at it's greatest, and when the wheel balance weights are on the side opposite of the sticky rotor section, vibration is almost gone, as if the wheel weights are countering the pull of the rotor.

Now what I don't understand is why my rotor is catching. It was catching on the new rotors as well, EVEN after I got them turned and measured. Is it possible my bearing or bearing race are warped? Is it possible the spindle is bent? Something isn't right here, but I think I'm close, though. I'm almost sure it's the catching rotor that's causing vibration at high speeds. It made sense that it would become noticeable after I did my brakes, because putting on new pads resulted in very little clearance between the pad and the rotor. The problem was there before, it's just that the rotor couldn't reach the pad, so it wouldn't rub and so nothing would vibrate. It's not as bad with the old rotors, because they're thinner.

So should I replace the bearing and races, or should I get a new spindle?

Do you make a habit of braking hard to a stop, then holding the pedal until the light changes? Or when slowing down on an off ramp?

Thing is, when you leave a pad clamped down on a hot rotor, some of the pad material can adhere to the rotor causing what feels like warped rotors. How likely this bonding is to take place is also largely dependant on the brand of pad.

I try to let my car roll forward a couple of inches, then brake again. Repeating until the light changes. I can't say for sure if this helps, but I've never had those type of issues again since I've been doing it this way.

Just a thought...

Not the case here, as it happened even after brand new rotors were freshly turned. I treat my rotors right. Never had any issues with rotors on other cars. There is a runout somewhere, but I don't think it's on the rotor. Maybe the spindle...

Any solution to this issue? I'm experiencing the same issue with my Re-Speed kit installed as well. However, my vibration is most pronounced when I turn the wheel just off center. I.E. when driving down the freeway in a straight line, there is no vibration... turn the wheel slightly left or right (as if changing lanes) and the wheel shakes.

BUT, if I am cornering and the outside wheel loads up, there is no vibration.

You should definitely check the spindle to see if it's still straight. I have no idea how to measure them to figure it out, and even the slightest bend could cause serious vibration. Worth it to have a look.

Agreed, a bent spindle would cause vibration, but wouldn't it vibrate even going straight? Also, I should note that the car didn't have this issue before the turbo build, respeed swap, etc.

The brakes, rotors, bearings, spindles, outer tie rods (have less than 5k miles), shocks (koni's), LCA's are all the same. I installed new ball joints, and had my buddy tig weld them in.

I am now running Diamond Racing wheels, but they were road force balanced and I saw the read out when they were done.... I set the toe myself, it's about 1/16" in.

I can actually jack the front end of the car up and wiggle the driver's side wheel slightly if I grab the wheel at 3 and 9 o'clock, almost like there is play in the rack itself. :scratch:

I am no expert but I do know that there is an adjustment for the preload on the rack. I bought a 15 to 1 rack to replace the 20 to 1 that came with the unit and it had very noticeble play like you describe so I loosened the big nut and tightened, ever so slightly the small nut in the center and adjusted out the play. I had my wife turn the steering wheel back and forth and let me know when it began to get harder to turn, and then backed the nut off just a little and them locked it back down. Play gone. I felt like I was messing with something that maybe I shouldn't be messing with, but it took the play out of my rack. BTW I love my 15 to 1 rack, much less steering effort especially with my big tires. If yours has free play it could cause the vibration.

2 cents....

The play is most likely not in the rack, but in the tie-rod adapters. The threads on those don't mate very tightly with the threads in the outer tie-rods, so I've had about half a thread of play. You can remove the play by screwing the adapters all the way into the outer tie-rods, but I think that kind of removes your ability to easily adjust toe for alignment.

I drove with that stuff tightened, and I think I had more vibration. Now that I have a tiny bit of play, the vibration isn't as bad... Hmm. And yes, it seems like vibration happens more when the wheel isn't perfectly centered...like when I'm changing lanes or going around a bend.

I also have weird crunches and pops coming from suspension when turning the wheel hard during parallel parking, or simply when jacking up the front end. Don't think it has much to do with turning the wheel and more to do with suspension geometry changing with weight transfer - something cracks and pops as a result of it. I took it all apart, I couldn't find any looseness or wear on anything. It looks perfectly good. I'm taking it to the pros next week, maybe they can sort it out.

That is exactly what it feels like.... very similar feeling I had with one of my old steering boxes that had too much slop. There is a vague feeling on center and the vibration slightly off center. With the old box, I adjusted it and it was much improved. I should also note that the vibration is most pronounced between 60-70 mph, and clears up quite a bit above 70 mph. Almost as if there is more load on the rack, taking up the slack.The same way it would when loading up the suspension in a corner. Oh, and I also agree the 15:1 rack feels amazing, one of the best things I've ever done to my car. I'm going to Google Fox body mustang rack adjustment and see what I come up with.

Still haven't figured this shimmy out. It's been more than a year now. Dammit.

Some new questions.

1) Is it possible to warp a rotor and hub during bearing race install? Just a little bit, but enough for the whole assembly to be sitting crooked on the spindle, so that it wobbles side to side a small amount?

2) Guys at the shop I took it to suggested that maybe the wheels aren't centered on the hubs. It's true the new brake disk hubs are a tiny bit smaller than the old ones. Maybe by a few thou. But it still vibrates with the old rotors and both stock wheels and Panasports, something it hasn't done before. Is there any merit to the hub-centric idea? I mean the Panasports I got are hub-centric for my specific model. How much play should there be between the wheel and the hub center? Is a couple thou enough to cause a vibration?

I kind of want to find someone with GSL-SE in Seattle, one that doesn't vibrate, and throw their front brakes and wheels onto my car just to test it. Posted a thread on this in the NW forum, and will pay cash money.

https://www.rx7club.com/nw-rx-7-forum-33/any-seattle-gsl-se-willing-lend-me-front-rotors-wheels-day-ill-pay-you-1002521/

Another possibility I thought of. Could I have bent my studs slightly when swapping them over from one rotor to another? Could that cause vibration? I've been looking at them and I can't really tell if they're straight or not.

Ok, so Jhereg let me try his front rotors and wheels, and it still vibrated, so I guess we can rule out brakes, bearings, races, wheels and tires. Plot thickens. This leaves us with the entire rest of the car. Ffffffffffffffffffffffuuuuuuu

Anyway, one thing I'm still seeing is that my gearstick vibrates up and down in sync with the wheel shake, and sometimes when the wheel is smooth the stick vibrates more and when the wheel is shaking hard the stick is pretty steady. I can also sometimes feel it through the seat and I see my hood vibrate a bit as well sometimes. It's something under the hood, or even something in the back and transferred forward with a driveshaft.

this is pretty wierd do keep us updated on whats goin on but just a random suggestion , sterring rack bushings?

Steering rack bushings what? I mean yeah, they're there and pretty tight as far as I can tell.

sorry didnt read second page, my bad but the poping u say when turning happend to my gslse when i replaced the struts n didnt tighten down to top nut on the strut tight enuf( and i used a 300ftlb nuematic air wrench i loosened it off n then put all little grease on the threads and let it have it with the air wrench n worked( my strut shaft was spinningf on the top when iwould turn the wheel) also maybe time to change motor mounts? i know i had minor vibrations at speeds but cuz my engine waz shakin around on hard turns n when i replaces the mount it was damn solid!

yeah that was a stupid suggestion i just sayed cuz on my truck that happend cuz they were worn( my se doesnt have a rack yet) n steering felt loose n when i would slow down whith the wheel in the same possition it would pull like i was turning the wheel in more, also couldnt align it cut the rack kept movin. this is deffinately wierd!

sounds like a pain in the ass but if you have the old worm gear box n parts around maybe try to re install them and see if it goes away but id save that for a lat resort. a few friends of mine have the re speed rack on their fb's n ive never heard them say anything about issues the rack but maybe a one in a million chance

If the shifter moves up and down considerably, your trans mount is toast. I've seem some strange issues arise from bad transmission mounts in many cars over the years. I'm surprised energy suspension doesn't make a poly mount for our cars, I'd love to have one.

I tried to read this whole thread buy may have missed it.

Have you renewed your idler arm? This is a common source of front end play and vibration that can be hard to spot even with the car up on jacks. I did one recently that didn't look that bad on the car but after removal it was obvious the bushings were toast.

The Moog unit, with ball joints, is a cost effective upgrade (check RockAuto), will last much longer than the stock unit that uses the bushings.

Whoops, never mind, I see in the first sentence you have a respeed rack and pinion installed.

im just adding that I need a solution for this as well. I have the entire respeed suspension, braking, and steering systems as well. For me the shimmy only happens at 50mph+ or left hand turns. if I pull the wheel right it eliminates the problem but then I am steering right, lol.

Anyway I havent narrowed it down yet and wondered if you found a solution. If I cant figure this out, I will just get rid of my respeed components and go with a s tock second gen steering system.

I too have just started driving my Respeed conversion steering and i have the same exact issue, to detail mine, its similar in almost every way, the vibe is severe but it comes and goes at highway speed, sometimes its silky smooth, other times beats you to death.

i just put a set of nitto neo gen 205/50/15 on the front, and all the ball joints and tie rod ends are new etc etc, its all new, the rack is solid mounted to the Xmember due to my space constraints of my build, and i have solid motor mounts and a poly trans mount.

the only mechanical anomaly i can find is if you grab the tire at the top while car is on the ground and pull in/out there is slop like a wheel bearing is bad, but its not in the bearing, and there is ZERO side to side play in the rack/tie rod assembly, its like the strut insert is blown out and not supporting side loads...but in my case, they are not old at all, maybe 6k miles, and the car exhibited no vibe before the steering conversion, not all of a sudden its there. oh and that play is on both sides, identical, not like 1 went bad and other is fine type of thing, something has changed....

so at risk of ruining my alignment im going to start taking things apart and try to find out how and why i have that side play, other than that, im at a loss, because everything is either new, rebuilt or not very old.

i think we need a whole forum for discussing the problems of the rack conversion, installing it was a pain and i had to remake some of the parts as they were not right, and now i have this issue, which it seems i am not alone.

It's now been two years. I've given up on this crap for now. I've gone to a number of professional shops and none of them been able to figure it out. I just get the usual speculation: "out of balance rotating assembly or wheels aren't perfectly centered on hubs, otherwise we have no idea". Come spring I'm gonna try swapping the stock rear brakes on as a last ditch attempt. Maybe the vibration is actually in the rear and is somehow transferred to the front through transmission/driveshaft (hence the vibrating shifter). I've had dreams where I figured this out, only to wake up to a disappointing reality.

I donno. I can't even drive the car anymore, because this vibration has loosened my steering column to where I have a bunch of steering play and probably need a new bushing, and now I have other problems to fix as well.

Have you changed your engine and tranny mounts? Also bad driveshafts & U-joints cause some pretty nasty vibrations

If you're seeing slop, pull the wheel off and perform the same test on the hub, the issue should be visible. If it's not, then maybe for one reason or another, depending on your setup, maybe the wheel is not being tightly bolted to the hub.

To be honest though, yours sounds more like a driveshaft or u-joint issue.

I got $20 that says on all these kits it is the RLCA setup that is used. I think the whole design was horrible from the start. I mean you have to remove the whole suspension just to adjust it? that's bs and laziness by design. when I totalled my seven the impact had sheered off the three bolts holding the right rLCA and the plate was wedged in by the frame (where it folded over itself) only after the accident did the car stop the shimmy I described in many threads.

I had the r/p kit on both my FB's for a while (6000 miles on the one, and about 15,000 on the other) and never could get it setup right. The bushings on those rear control arms were completely shot on both my cars after only a short time, and the control arm bushings weren't too far behind either...

I wish I could be of more help getting your vibration sorted out, but I could never fix the issues I had on mine either and ended up selling both kits - haven't looked back

Well if many ppl with the kit are having issues, maybe it's time to return to stock & see if the vibration disappears.

i dont have the option to return to stock, i have to find a solution and preferably quickly...DGRR is a month and a half away....and as far as Ujoints concern, no, im 100% sure that is not the cause, i have already been down that road for another reason.

i too think the control arm set up is at the very least insufficient, so ill be looking into something different, perhaps a whole fabricated lower arm or something, all i know is this is for sure not just my car at this point.
its just so odd how the vibe comes and goes, but only does it at high speeds of 60+

i wish i could have and probably should have used the second gen subframe, but i would have had to mod the hell out of it and probably been worse off...

first i need to find out what that strut noise is....and go from there, after that im going to see about maybe beefing up the control arm situation

kinda wish i still had the stock steering arms to put on and try...but alas..i gave them away..

85 Turbo, I just re-read this thread and I think I may have found your problem.

I had been dealing with this same issue and I thought I had solved the problem by adjusting the play out of the rack, but It came back, or was never completly gone, so I kept looking and I FINALLY found my problem once and for all. It was in the steering shaft where the two shafts slip together and are held by the aluminum rod that acts as a sheer pin. When first installed the aluminum pins held tightly enough so there was no play between the two shafts, but after awhile they loosened, just a tiny amount. The free play was almost impercevable, just a couple thousandths of an inch. When the problem was at its worst I could barely and I mean barely feel the free play when the car was sitting still and I would ever so gently move the wheel back and forth feeling for it. I took the shaft out of the car and found the free play, barely a "click" when I would twist the two shafts in my hands. I put the outside shaft in a large vice, pressed it against the inner shaft as hard as I could to remove the free play and reassembled. All the vibration problems I had been dealing with completly dissappeared. It was like a different car all of a sudden. But....after I drove about two months the problem returned, I took it back apart, installed shims between the two shafts by driving them in tightly between the shafts on the flat sides, and it has fixed my problem, months of driving with no further issues. I hope this helps you find your issue.