Vibration under acceleration only till 70

[Flowgoode]

Ok, my problem consists of my car vibrating/thumping pretty bad under acceleration only until about 70 mph, then it goes away and the car is as smooth as can be.

The car doesn't vibrate (more of thumping feelings) when I left off the gas.

I think it might be the axel or something. The transmission is leaking from the passanger side axel seal and needs a new seal aswell, but I don't think a leak (keep in mind I fill it up constantly to replace the lost fluid when I have to drive that car) will cause the thumping.

Any ideas? I can't figure it out. And I don't want to buy a new axel and not have that fix it.

I have a 93 TSi AWD 23 spline (but the trans is unknown year, but bolted to the transfer case I had stock, so its a 23 spline i know that much).

[98rs_sleeper]

i have a 98 eclipse with the exact same problem. first and second gear do it the most but third and up smooth out. i replaced my right front axle and it still does it. i leak tranny fluid from that side too. if anybody has any answers this will kill two birds with one stone.

thanks

[Mr.TT]

I've been plagued by this problem for a while. I'll describe my problem in full and you can see if it matches up: My car would wobble (not a fast vibration, maybe 4-5 wobbles a second) any time I accelerated, would dissappear completely when off the throttle and it would smooth out by maybe 90 MPH.

Boy did I get diagnosed with everything. First thing I did was I got the tires balanced. Nothing. Alignment? Got that done, nothing. My right CV boot was shot so I said what the hell and bought a whole new right axle. Nothing. RRE looked at all tie rod ends and suspension components and everything checked out. Driveshaft seemed ok, didn't throw any weights and the carrier bearings were ok but with no real way to test it I was leaning heavily on that being the problem. Finally as a last ditch effort I swapped wheels front to back and the problem became the exact opposite aka wobbling under deceleration and fine under acceleration. Ended up being the tires/rims anyway even though they balanced.

Anyway, check out anything that changes the dynamics of the car under load, axles, CV, tie rods, pretty much all suspension, and the driveshaft. Does the steering wheel wobble or is it the whole car? Any noises? Hit any curbs or the undercarriage at all?

[AngryScientist]

check to see that your axel c-clips are holding the axles all the way on, i had a problem like that under cornering and heavy acceleration. i went to pull the axels and one of them basically fell off as soon as i tried to pull on it.

[eviltalon91]

did you check your drive shaft carrier bearings????

[ProStreetOnline]

did you check your drive shaft carrier bearings????

Good idea, I would check that.

[Flowgoode]

what would i look for on the driveshaft carrier bearing?

I have some curb damage, but never any problem till after my tranny swap.

[Mr.TT]

pretty much just get underneath the car and wiggle the driveshaft around. The bearings should provide some resistance... if the driveshaft just flops around then the bearing is bad... you can fill it up with silicon though.

[98rs_sleeper]

i think it would have something to do with the tranny cause everything was fine til i installed the competition stage 1 clutch kit. now it does it but we replaced the right axle and now the left side leaks. were going to the shop that helped put it in today and were gonna look over every possible aspect of what it could be. thanks alot!

[MaNGiNa24]

I just started having this problem earlier this week, I'm gonna get a new set of raxles and come back with the results.

[MAD_TRBO]

Yep I would check the carrier bearings. Did you possibly recently install a new exhaust system and perhaps the alignement of the system is very close to the drive shaft. I am assuming AWD, I know my shaft was out of balance and would knock against my exhaust which made the car feel like something was coming up through the bottom of the car. This would only take place in a limited range of speed.

[1Fast_Tsi]

the problem is the rear carrier bearings or maybe bother. its not really the carrier bearings its the boot around the bearings, go under the car and move the driveshaft, it if moves more then a quarter of and inch and u can push on the boot if it moves alot then you need to replace them, if you go to vfaq.com and then go to drivetrain then look for driveshaft and look for carrier bearing thump fix, i am in the proccess of doing it to my car right now, just make sure you fill the bearings all the way and let it sit for 48hours, the first time i did it i let it sit your 5hours then bolted it back up and then another 24 and when i drove it alot of the sylicone leaked out and wasnt dry all the way so let it sit as long as possible.

[98rs_sleeper]

all of that would help if i was a gsx or a tsi but im an rs. good ole fwd non-turbo. were replacing the left axle seals today to see if that stops the leak but im still stuck with what that vibration is. any answers will be greatly appreciated!

[1Fast_Tsi]

oh i didnt look at that i thought you had awd, you should check your control arm bushings, and your wheel bearings, if the bushings are bad it can cause your wheel to move back and forth, when my wheel bearings were bad the car was shaking at 70, other then that i have no idea.