Tackling my vibration issue..

[Brav]

Ever since I have put on my new JHM rotors, EBC reds and Rotiform wheels, I have had vibration issues. It started after I tried to brake in the pads. I had horrible problems with pad buildup and vibration under braking. I tried many times to re-bed the pads, and the hard decel runs one day became violent.. the whole car was shaking so bad like it was going to come apart. Well, this was the end of all my control arms.. so I swapped all the control arms for new ones and this helped significantly. At that time I had my rotors turned too which eliminated the vibration under braking. Great.

But ever since then, I have had a somewhat inconsistent high speed vibration at around 70mph. I went back and re-balanced all the wheels, all where fine. Road force on one rear wheel was a bit high but not terrible. I swapped back to the stock wheels anyway, just to eliminate the issue. Well, I still have it, but now its back more into the steering wheel than in the seat.. it comes on around 55mph, and goes away around 65.. this car and its mysteries.

My guess at this point is that my hubs or axles or some other drive train part was bent under the super hard and violent bed-in process.

My question is... whats the procedure for checking or true-ing the hubs? Any way to check? Any other suggestions?? months of continuous high speed vibration is driving me NUTS!!!!

[ben916]

what about the ROTORS??? front bearings?

I have my old OEM rotors that have some meat left on them, you have to come down and get them, try them out on the freeway, then you will know for sure that it is/isn't the rotors...

[MaxRS6]

I had experienced vibrations under heavy braking at the track. I replaced the wheel bearings and that resolved my issue. However; it was an expensive fix- but it was probably time as I had rolled about 150K on the OEM set. I don't have a clue if this is your issue but thought I would throw my experience out there.

[Brav]

From my experience and from research, warped rotors are unlikely.. I had them all turned. I dont have braking pulsation/vibration anymore.

Bearings are possibly, i have over 140k on the car now, and the crazy vibrations I had with bad control arms may have torn the bearings up.

Max - what was the price for bearings/labor?

[JSRS6]

You can do the bearings yourself. They run anywhere from 80-140. Not hard, just remove the upright.

[Brav]

Good to hear. I did the control arms myself (big learning curve.. but got er done) so I can imagine myself doing the bearings. May be time to do it anyway. Might be a good idea to check the hubs as well at that time, or is that unlikely?

[JSRS6]

Just take a wire brush to them if they have rust or buildup. As long as they are clean, the wheel should seat properly. Highly doubtful the hub would be messed up with floating rotors and aluminum hats.

[JSRS6]

I'm doing my upper control arms/wheel bearings soon myself.

[Brav]

Did you buy the bearings from the dealer?

[MaxRS6]

I actually purchased the bearings from Pat (v8weight). It is my understanding he can't provide them now as he has changed jobs. The parts weren't bad, but the stealership raped me on the install.

[Brav]

Fair enough. Looking at the diagram, seems easy enough. I changed the axle myself, and its only 1 extra step from that.

[RSSIK]

i can get the bearings for you brand new.. Not from the dealership but they are OEM parts not just OE. correct me if I am wrong but SKF is actually the company that makes them for Audi and I can get them for $118.38 each. this is the kit part # 8E0 498 625B it is a whole kit not just the bearing and these are the items it includes.. bearing part # 4D0 407 625H, dust shield part # 4D0 407 623B, (4) ball screws part # 4D0 505 445 and last a shouldered bolt part # 4B0 407 643A. Any other questions i can try to help with itll be my pleasure.

[Brav]

Thanks Dynasty, in my currrent research, thats kinda what I found out too with SFK. What I cant figure out is if the rears are identical.. some companies just sell the bearing itself for rears. Including SFK.

[RSSIK]

For some reason they dont have a listing for the SFK rears they only come in a company called FAG.. but is still listed as OEM.. go figure! the rear in this brand comes in 2 different ways. one is just the bearing and one is a bearing with a bolt and nuts. doesnt give any exact specs on nuts or bolt but in the picture provided it shows one bolt and 4 nuts 2 sets of 2 each. 2 silver 2 black nuts and 1 black bolt. and of course the bearing. pricing is available if your interested. These are my wholesale prices, no tax or shipping unless your not local.

[Brav]

I appreciate the help Dynasty, but I called my local shop (supremepower.com) and ordered from them for a great price.. in stock, have em today. The rears are actually supplied by FAG (er... F.A.G....) not SFK.

[RSSIK]

Thats great. Your welcome. Glad you got the parts you need. Good Luck

[MaxRS6]

I hope it resolves your issue and that I did not send you down the wild goose track...

[JSRS6]

The difference is the fronts are bolt on, and the rears are press in. But our rears are upgraded from the a6/s6.

[JSRS6]

So to answer your question, the rears are sold as bearing only for press in.

[Brav]

I see.. so I will need a special tool for that?

[bmlee007]

^^^

This is the tool set ECS sells for bearing removal and replacement, but you may be able to rent it for free from your local AutoZone.

http://www.ecstuning.com/Audi-RS6--4.2T/Tools/Drivetrain/ES1306825/

[Brav]

Thanks! :rs6kiss: