Whisper

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?

snivley whiplash

iTrader: (4)

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

DivinDriver

iTrader: (15)

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.

Whisper

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...

orion84gsl

iTrader: (5)

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.

Twilightoptics

iTrader: (1)

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.

2GSLSE

iTrader: (6)

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.

orion84gsl

iTrader: (5)

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.

Whisper

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.

Twilightoptics

iTrader: (1)

I'm thinking too loose.

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

Whisper

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.

DivinDriver

iTrader: (15)

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

rxtasy3

iTrader: (2)

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.

Kentetsu

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...





.

Whisper

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

Whisper

[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?

Kentetsu

Ujoints? Tranny mount?

Redliner223

iTrader: (6)

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.

Jeff20B

iTrader: (13)

Get one of these. Competition Transmission Mount

http://www.racingbeat.com/RX7-1975-1...ate/12050.html

Whisper

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.

82transam

iTrader: (18)

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.

Whisper

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?

Kentetsu

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...

Whisper

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...

81WideMariah

iTrader: (8)

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.