Hi guys,

I just replaced both front axles (DIY) with reman's from NAPA, and now when I use the throttle heavily between 35-60MPH, the whole car seems to shudder. As soon as I lift throttle, it abates. No feedback through the steering wheel at all, no problems when coasting or applying throttle in high gear at these speeds (5th gear at 30-40MPH in TIP mode).

I did the installation with a lift and air tools, and it was not difficult. I did have to remove and replace the pinch bolts, and I am having the car aligned at the dealership as I post this. I balanced all 4 tires during this service as well. I caught my brother-in-law (he was helping me) unsuccessfully trying to remove the pass. side axle nut with an impact wrench while the car was on the lift, as opposed to using a breaker bar with the car on the ground. Could that have damaged the transaxle in any way? Do I need to smack him upside his head?

Could those reman axles be the problem? I did get a quote on a set of axles from Marty Cook at RAXLES, but they were still $200/ea., and I decided to go with the NAPA reman's instead. The service advisor at the dealership is initially blaming the non-Audi parts (naturally). $800 per axle, Audi? Really?

Sorry for the long post....

 

Back from the dealer. Spoke to the tech himself. The output shaft bearing on the pass. side is worn. Their only 'allowed' procedure to repair this is to replace the whole tranny! WTF??

The tech said that if the side casing was removed, the bearing might be pressed into the casing itself or pressed on to the end of the pinion gear, and could be replaced...just not by them. Any sage advice from someone who has had this done would be stupendous! I am calling a few transmission shops with Audi experience to validate this information.

-Steve

 

Need a referral to a reputable Transmission shop with ZF experience in the Atlanta area that I can contact for a diagnosis. I called Ron at TBR, who does rebuilds for indy's and dealerships but not the general public. He gave me some diagnostic advice and a few more nuggets of good info.

 

Keep us up to date on your progress. This might be the cause of the vibration I've had for years.

But, you also might want to get a second opinion on whether the looseness is causing your vibration. Many people have reported loose stub axles without any vibration. And, you car wasn't vibrating before you changeed axles, was it? So, the axles are still the most likely culprit.

Bob

 

I put the car on a lift last weekend and thoroughly checked the axles and the flanges they're bolted to as well as all the front suspension components. I could not find any excessive play, and I also could not see any evidence of them binding. I did not check the center driveshaft (propeller shaft) for any play at the center bearing/U-joint. The problem is markedly worse when turning a corner from a complete stop after applying almost full throttle. I thought the friggin' wheel was gonna come off.

One more thing. The problem is almost non-apparent when the car is first driven (cold). After the engine/trans and tires warm up is when it's most noticeable.

Could this be a tire issue at all? I have crappy Hankook Ventus V4's on it that are unevenly worn.

 

Could be a tire issue except tire issues appear more when cold and go away as the tire warms up and you seem to have the opposite problem. Sounds like a bad CV joint to me. To inspect that properly you need to remove the axle. Is it worse when turning in one direction as opposed to the other?

Bob

 

Here's what I did before it went away:

The tires were out of balance, so before I intended to take it to the tire shop for a balance, I removed all the wheel weights from the 2 previous balance jobs....one done poorly. This did not solve the shimmy, and made the car shake at highway speeds regardless of throttle input. That was expected.

A week or two passed and I still did not take it to the tire shop..too busy. I picked up an exceptionally nice 3-ton floor jack at a garage sale and wanted to test it out, so I jacked up the front end and spent some time thoroughly inspecting the front suspension and the recently replaced reman axles. When the wheels/tires were off the ground, they would freely rotate about 20 degrees in either direction and then hit the gear(s) in the tranny which stopped them from rotating. I spend about a minute on each side rotating them back and forth, 'bumping' the axles up against the gears in the tranny, wondering if this much free rotation was normal. When the car is on the ground and you put it in park, it rolls a bit before coming to a stop. The next day, the shimmy was gone. I tested this thoroughly by getting on the throttle every chance I could to try and replicate the problem. Now all I have is a mild vibration from the wheels/tires because they have no weights and are OOB. So, is it just PFM? Did I 're-seat' or 're-align' some gear mechanism by rotating the axles to their stops in the gearbox? By having the wheels off the ground for 2 hours, did I 'un-bind' one of the reman axles (if it was binding at all)? My answer to these, ladies and gentlemen, is synonymous with the difference between ignorance and apathy....I don't know, and I don't care. I am about to replace these gawdawful Hankook Ventus V4's with Conti DWS, so we'll see how it drives after that.