BigWhiteGTP

Okay before todays 4 tire balance, the car would shake at speeds 75mph+, mostly to 85 then it would shake as bad. Now the shaking has moved up 10mph to 85mph or so. I just paid $52 for this, which I felt was pretty steep for a balance, but after months of putting it off <----dumbass and broke) I just said do it.

Maybe they messed 1 wheel up and I should take it back, but what if the tires are all balanced and fine. What else could it be? The only thing I can think of is the crappy/missing endlinks and here is why:

On my GTP when I lowered it I had to removed the middle link in the front sway bar bushings, or else it would cause the sway bar to flop and shake the whole car around 40-45mph and horribly under WOT. Now since the rears sway bar endlink bushings are rotted and gone (broke off) I have come to the conclusion that this may be just like the GTP.

I have a stock Aluminum DS ( I have seen it and the RPO code says so as well) so it can't be that, can it?

BigWhiteGTP

Btw, even idle is shaky. Thinking about bad u-joints? Is it obvious to tell if they are worn?

BRobinson

Does it do it while creeping along at idle? In park? I'd check engine and tranny mounts first before anything. Either way, you should replace the swaybar bushings.

92'Sleeper

Replace the Sway Bar end links & Bushings since there toast. Very cheap upgrade.

Check to see if you could have a bent axel. If no bent axel,
Have your driveshaft checked. They will look at your Yoke's, U-Joints, shouldn't cost no more than $75 for a rebalance. Costed me $70 to correct a tight slip yoke & rebalance the driveshaft. It was also a bad vibe around 75 mph.

naf

iTrader: (7)

It's easy to check whether your sway bar end links are causing the problem. Take off your rear bar completely and test drive it, but that's probably not the problem.

Check your tranny mount by placing a jack under the trans (use a block of wood to keep from denting or scratching the tranny. Jack it up just a hair and watch the tranny mount to make sure it hasn't separated or is loose.

U-joints will usually cause a clunk when shifting from drive to reverse, a bad tranny mount may cause a similar sound.

Vibrations can also be caused by warped front rotors. Rotors can warp from wear, overheating or bad front wheel bearings.

There's some good threads here that will give you alot more things to check.

BigWhiteGTP

naf, I replaced the tranny mount shortly after I bought the car in January. A bad tranny mount, when the tranny shifts at WOT, feels like a bowling ball dropped onto the floor of the car. It's definately not that.

However, there is chunking when shifting from P to R or drive. So that points to the U-joints? But are they easy to tell if bad or is it once they "chunk" they are bad?

I don't think the rotors are the problem because they act fine when braking, usually when they go out they will cause vibration when braking.

naf

iTrader: (7)

The " clunk" is an indicator that they may be bad, however other things could be causing it. Worn u-joints could be causing your vibration. Jack up the car and check them for play. If you're unsure about checking them, ask a shop to look at it for you. I wouldn't just replace them unless you're sure they need it, especially if they're the sealed, original joints.

Vibration can have alot of causes, from an out-of-round tire (even though it's balanced) to a worn yoke.

BigWhiteGTP

Well, if it clucks like a chicken, and tastes like chicken......then it could mean it's the U-joints?

Worn yoke, is that on the rear end? Because I got a complete '89 3.42 posi rear end waiting to go in. LMK on that.


And about out of round tires, I guess I can see if I can borrow someones whole wheel set and see if that cures the problem, but it won't stop the clunking. Of course getting someone to say "Yeah sure, sounds like fun!" will be a little like pulling teeth.

Let me know Naf.

Thanks btw!!

Stevo

iTrader: (45)

i get bad vibrations past 80mph too

My car clunks and im pretty sure i have a worn U joint...i havethe new part i just need to find time to drop the driveshaft...ive never done this but ive heard its not hard...ill find out the hard way...

naf

iTrader: (7)

You're waiting to install a new rear? Get it in, replace your endlinks and then see how it's doing. The new rear will eliminate half the possible causes of your vibration. If it still vibrates after the swap, come back.

If you're going to higher gears with the new rear end and the vibration speed drops you're looking at driveshaft/tranny issues. If the speed stays the same you're left with your wheels.

You're going to swap it anyway, right?

BigWhiteGTP

More and more it's sounding like the ujoints. But before I do the swap I have to get a proper jack to hold the rear during removal and install.

naf

iTrader: (7)

Just don't swap your u-joints unless you know they're bad. The factory sealed ones are practically zero maintenance and replacement joints with grease fittings can be a pain to get at and lube. And the replacements are like $15-20 each.

Where are you guys driving more than 80 mph?

BigWhiteGTP

The car has been doing the clunking into R and Drive since I bought it and so have the vibrations.

I'm going to try and see what is shifting when it shifts, I'll have my bro or Cuz do the shifting and I'll look under the car. Will the DS move if its the Ujoints?

I just don't want to install a rear end and not do the Ujoints, then find out right afterwards that it was the Ujoints you know?

My girly and I are goind to San Diego and we want to take my T/A but driving under 75mph, will take forever.

jack_sparrow

iTrader: (1)

I have a bad shake at about 85, and can attest that it isn't from the driveshaft u-joints, or the tie rod ends or bushings, becasue all of them have been replaced. i work at Discount Tire co. in Longmont, Co, and put mine on the balancer. i did what is called a "Road Force" balance and what it does is measures the heavy spot in the tires and wheels and tells you where to line them up so there is less wieght to put on and less vibration. The second and more improtant thing that it tells you is your rim runout, and whether it exceeds the recommended limits for your size wheel. I found that my back two were quite a bit out, so i ordered two new 16 x 7 TT2's. Should be in today, i'll mount and balance them and let you guys know if you are interested.

Brett

naf

iTrader: (7)

jack-sparrow has a point. A good quality tire (and manufacturer recommended size) will solve alot of vibration problems. The road force balancing is supposed to be the cat's meow, too.

When you drop the rear, you'll have to take out the driveshaft. You can check it then for wear and play, or take it to a shop to get it checked. You can buy u-joints before hand and take them back if you don't need them.

wwnf

iTrader: (1)

I had a high speed vibration problem one time when I got new tires. The tire place balanced all 4 of them twice but I still had the problem. Took my car to another shop and they said that they had a better balance machine and did all 4 tires. No vibrations now. So did they really have a better balance machine or was it the operator? =) I'll never go back to Tire Express!

BigWhiteGTP

Well, I'll take it back to have them do it again.

Naf, ever since you said that a clunking into reverse or drive would point to ujoints, well I have that.

jack_sparrow

iTrader: (1)

One last point i want to point out is to double check and make sure that the rims you bought are whats called hub-centric, meaning the hub of the rotor centers the wheel, cuz that's how they are balanced on the balancers. If the lug nuts actually center them, make sure they use a plate with threads on it comonly refered to in the shop as a "spider'. You can buy "hub rings" and they will center the wheel on the hub instead of the lugs, and they are generally pretty cheap.

Brett

BigWhiteGTP

They are the stock wheels.

Okay, so regardless of the vibrations, the tranny clunking into gear is a symptom of a bad tranny mount , worn U-joints, or.....anything else?

jack_sparrow

iTrader: (1)

Sry, well, still good idea to keep in mind

brett

naf

iTrader: (7)

The clunking could be a number of things... worn bushings in your rear suspension, tranny issues, rear end, etc.

Swap rears and have new joints ready in case you find them worn. Then see how it does.

BigWhiteGTP

ok