fastest ive been was 140, and it felt like the car was gonna shake apart...i threw it in neautral at 140 and all the shaking stopped...so its obviously drive train(its an a4)....I do have the aluminum driveshaft(im guessing thats the reason). Cant they get thrown outa allingment and have to get balanced?

heres my mods.

 

get an LS1 driveshaft ~ $200

 

How old are the tires? U could be in need of new tires/alignment.

 

tires are new...i was thinking the same thing, but like i said, it stopped when i threw it in neautral...so im 90% sure its the driveshaft i guess...I thought the alum ones were supposed to stop the shaking that the factory ones did..and how are the ls1 shafts diff from mine?

 

Weird, cuz my car actually did something similar (not at quite that high of speeds) but it turned out to be a developing miss that was happening on a few occasions. mine also stopped once i threw it in nuetral.

 

My car does the same thing. Once I hit about 70mph it starts like the whole car is about to fly apart and when I hit about 100 it stops. It also stops when I push in the clutch or put it in neutral. I've been trying to figure this one out for about a year now.

Sorry I can't help,

Jason

 

The driveshaft will still be turning at the same speed if in gear or not. The rears still turning, so is the driveshaft. The only difference is there won't be force on it. My 95 ta had a humming rear when I was on the gas, but if I let off it went away. So it could be something in the rear. This is just a guess, but like I said, driveshaft still spins at the same speed in or out of gear.

 

i have the same problem i just got a 99 ss alum.ds i found out that my u joints were bad when i did the switch, get it looked at. the car drives smoothly now but i have not been past 60 yet to test sorry ill make it back to ya on this

 

letting off the gas would also take pressure off of the u-joint, so thats a definite possibility, didn't think of that before...

 

Had similar issues with my LT1 and steel shaft. Car shook like it was going to fly to pieces. Took it out and had it balanced. The guy who did the job, felt that it was actually in very good shape for a GM shaft which he said were notoriously bad. In any case, runout was .013 at max, and he balanced the shaft to within 1/10 th ounce. MUCH better. Took it up to 100 mph the other day and it was quite smooth; no noticeable vibration at that speed.

 

Hmm, mine did the same thing. I got an LS1 drive shaft and it didn’t fix it.

So, bad u-joints could cause this? How much to the cost, and are they easy to replace?

We’re talking those 4 bearings on the “+” shaped things on each side of the shaft right?

Thanks
-Jason

 

what type of shop balances the driveshaft? Any mechanic shop?
Also how much would this cost?

 

lingenfelter driveshaft! Bigger than LS1 or 1LE.

 

My car had the same problem and I got the wheels balanced and it runs so smooth now. If you get a new driveshaft and the problem is not sloved try getting your wheels balanced.

 

Doesnt necisarrily mean anything. I believe that it probably is stronger, but the LS1 driveshaft is bigger than the 1LE and it isnt as strong as the 1LE so you cant totaly judge by size unless you are talking about a *****.

Ben