hey all. as some of you may know, i bought a second park avenue in march of last year. over the past year, ive been slowly dumping money into making it like new as far as the suspension and steering go. ive replaced almost everything, but i still have an issue. when im accelerating, or even holding speed above 20mph, and below 30mph, i get a very odd very fast vibration from the right rear of the car. i cannot seem to narrow it down. my only thought on what it might be is the wheel bearing, as its pretty much the only component that has not been at least looked at. it seems good doing the 12&6, 3&9 shake procedure, but at this point i feel like i am chasing my tail.




here is a list of all the parts i can remember replacing off hand.

front control arms
front tie rods (inner and outer)
ALL body mounts
sway bar links and mounts front and rear
shocks and struts
brakes
axles
different set of wheels
and the rear trailing arms.

im sure im missing a few components.

ive tried prying on everything i can pry on front and rear. the steering rack is slightly loose, but i cant see it causing a vibration in the rear. especially considering the car is in alignment and tracks straight. the only other thing i can think to do is compress the brake caliper and pinch the brake hose and go for a drive and see if its still there to eliminate the caliper. otherwise, im thinking the bearing.

before i dump yet another chunk of change in this car i thought i would ask for some advice. i am thoroughly stumped!

thanks guys

When it comes to bad vibes and with all the work & things you have tried & also at a slower speed, sure makes me also think the hub/bearing.
If you are absolutely sure it is the right rear, I would also want to see both rear tires up on a balancing machine to be sure it is within spec & not a slightly out of round rim or even a bad tire belt.
What is the tire pressure at cold?

Yeah, if it wasn't right rear, I would be chasing a misfire, because that is right about the the the car hits third gear

tires are all at 30psi, although i did try my mustang wheels, and the vibes are still there at the exact same speed. which eliminates the wheel.


im going to go dump some money on a bearing in the am and see where that gets me. if i remember correctly the rear bearings are a nightmare because its steel going into aluminum. on a 16 year old car, in the salt belt. we will see how far i can get before work.

only thing i can think, is without any play its got to have a flat ball bearing or 2 in there. we shall see. thanks for the input guys!

You may also try pushing tire pressures higher. I am not sure how bad it is on 16'*, but on my 15'*, anything less than 35 PSI usually wasn't any good, despite what the sticker said. I usually had them pushed up to 40.

To me, a higher pressure would amplify a vibration problem......in your particular problem, it might have been the brand/quality of tire......

well, i replaced the bearing... no change. wednesday im going to do a complete brake job on the rear.. again.. and remove the caliper and inspect it while im there. im suspecting that maybe after a brake press or 2, the rubber dust boot may be binding with the twisting action of the pistons ratcheting mechanism. the rear rotors are slightly warped. first brake job i just did the pads, knowing better. this time im going to do it right with all new and coat the heck out of that dust boot with some syl-glyde.

it sure is nice having a second car to drive in the mean time. having that vibration all the time would drive me absolutely bonkers.

after the brakes, the only possible thing i can even imagine it being is the tire possibly having too much toe-in. although to the naked eye it looks identical (mirror image) to the driver side. im sick of tracing this damned vibration. im running out of ideas!. next step is maybe shock mounts, but i dont think they would cause this.

Even if I had an Afro, I don't think I would have any hair left at this point.
The good news is that you have a spare bearing.
I sure hope that the new rear brakes are going to make it right Jason.
New rotors or are you going to have them turned?

new rotors. they are so thin to begin with, i dont know if it would even be legal to turn them. got em for $20 ea with my discount, so it wasn't really worth it to turn them.

brakes didnt fix it, although the dust boot was twisted. rebuilt the calipers while i had everything apart just for good measure.


i did notice the shock mounts are slightly loose. going to do them friday then its back to the alignment shop. if that dont fix it, i honestly cant think of anything left to fix. guess if the mounts+ alignment dont fix it its a mystery that i cant solve.


this is the part in question. http://www.rockauto.com/catalog/more...nid=453&jpid=2

well, mounts didnt fix it. had it aligned, and put the wheels from my old car (current daily driver with NO vibrations) on the new car, and still have the vibration. took it to a shop i deal with at work, that i trust. he couldnt find any issues either. he even took me into the shop and let me pry on everything with the car in the air. only thing i can think to do is duct tape a camera down there and go for a drive. but the vibration is so harsh i think itll probably vibrate the camera so much itll be a blur.

either way, i cant find it. only 2 components not replaced are the control arm and spring. and i really cant see either causing a vibration. guess its just a mystery.

just wanted to update you guys.