trying to diagnose a possible suspension problem

NYSpeed Automotive
1

i am sure i am gonna gt audi/vw hate posting this, but i have a problem that is not easy to diagnose and therefore i am stumped on how to solve it. i thought i had an idea but now i am borderline “throwing money at it”

the problem is what i consider a vibration similar to a wheel being out of balance. but it isnt as simple as that and i will try and explain why without being long winded.

when i really noticed this problem i was running summer wheels. 18x8 iforged variants. i took them off to put r-comps on at an auto-x and noticed one wheel was bent. ugh. that is what i thought the problem was.

a very gracious nyspeeder has let me borrow wheels to run on the car since then, a little over 3 YEARS. in the little amount of time i drive the car whith the borrowed wheels over the past 3 years i would sometimes feel what i thought was the same vibration, but nowhere near as bad. even if i had felt it more, i am seriously convinced that my mind would disregard it as road, not a problem with the car.

ok at this point the car was lowered, and had been realigned, but that alignment might have been knocked out of whack at some point. i cant say for certain or not bcause the timeline is shotty in my mind as far as when certain wheels were on etc.

so i get the time and finally the money to start paying better attention to my car. this means repairing my wheels that i overpaid for considering they are so weak and cant be driven in the rain (whoooole dif story). i weld a crack, have them checked for being straight, one is out of whack so i get it straightened. apparently the way it is bent makes it difficult to repair. basically the wheel was collapsed on the diam, as well as pinched on the width axis. so he repairs it within his ability and i got to get tires mounted and balanced. the tech said he balanced it and it ended up being fine, except he had to use the max amount of weight to get it there.

vibration was mostly gone after this, but i still felt it “sometimes”, i think? but at least it wasnt all the time so i thought i was going in the right direction. so i threw the new coilovers in to get more gooder handling, drove the car away and the thing is vibrating like a monster (in my mind). where before it was usually a high speed vib. now i can feel it at 30 and up.

ugh this is already long winded. sorry. i got an alignment tuesday (goodyear on sheridan, see ralph cuz he took care of me and made sure to do his best). now the alignment is done within specs (toe, camber) and the vibration kind of got better, i think, maybe?

so basically i dont know which way is up. i have a vibration that comes and goes, but i think really it is always there but road conditions etc might numb me to it. wheels might change it, but the wheels i have on it now were supposedly fixed to true and that didnt help? alignment is in spec. what do you think it could be?

2

a)worn bushings/boots?

b)wheel still fucked?

c)wheel balance?

d)what tire pressure are you running?

I would probably go with “a” for starters. Time to do a thorough inspection of your suspension components.

3

i know most of his control arms are new…

4

Still sounds like the bent wheel could be causing a lot of this. Weights will only take care of so much out-of-round. Have you had it up on a lift and run it at highway speeds? Also, how is the front CV joint on the rear driveshaft?

5

yeah, most of the control arms are new. i believe the lowers in the front were replaced since those are the ones that typically have problems, and i did it as sort of preventative maint.

the problem is suspensions are still a unknown zone for me as far as what should be normal etc. so i could stare at the bushings for hours and unless there is an obvious gap, tear, deterioration, i will most likely not know what to look for. my first guess would be extra play on the horizontal axis, similar to checking for wheel bearing damage, but i wouldnt be sure. plus i would think the inspection would show any major signs of something being wrong.

tire pressure is even and to spec.

since i am so up in the air about this i was actually thinking of horror stories that may apply. out of balance crank (even though i would think that might be obvious due to the motor sensors being so sensitive, hmmm or not), fuct axle, driveshaft fuct?

then again it could def just be the wheels and the rest when the wheels arent on could be in my head. see why i am starting to just throw money at it?

6

Do you feel it in the steering wheel or in your ass?

7

Are you getting any weird/uneven tire wear?

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um both. i think the vibration is bad enough that it shakes the steering wheel. i can feel it in the pedals as well.

9

I’d take it to a shop and get a second opinion on the alignment and wheel balances. But like you said, that’s kind of the beginning of just throwing money at it.

But, bracketracer’s in here. Do whatever he says.

10

I’m thinking wheel, or maybe even tire issue. I think there could be an issue with both sets of wheels and tires you are using. Like the one set has tires that are worn incorrectly, the other it’s a rim issue. I’ve had that once before, and was like “both sets can’t be fucked up!?!” but they can be.

X…

11

Actually here’s a thought: If S4’s and MKIV Jettas have the same bolt pattern you’re welcome to grab the wheels off my car for an hour this weekend. My tires are noisy as fuck but smooth. It’d be an easy way to tell if it’s just a wheel problem.

12

^not the same bolt pattern.

I would think it has to do with the halfshaft, cv joint, or maybe differential acting up

13

hmm, if i werent leaving for cedar point in a few hours i would take you up on that. although now that i think of it i dont think your wheels will clear my brakes. but it wouldnt hurt to try. i believe the bolt pattern is the same crazy/stupid/awkward/one of a kind 112x5.

14

Jettas are 5X100

15

Eh I just did some checking. MKIV Jetta’s are 5x100, S4’s are 5x112. Maybe if you knew someone with a 1998+ Passat…

http://www.ronalusa.com/cars.html

16

Oh really.

I have a 99 Passat, but i doubt the 15 inch rims will clear your brakes

17

You can try my Passat wheels, they are 18 x 8.5 with a 32 offset, I think that clears your brakes.

X…

18

That could work. Xander with the save…