Driveshaft Vibration? - BMW Forum

441tech · 06-25-2006, 03:21 PM

Hey all-

Well, this one's got me. My '99 323i has an annoying vibration that is amplified between 55 and 65 mph. Everything is new on the front of the car, except the strut tower pivot bearings, but I know they aren't causing THIS problem--no way.

I ran a search in the forums about this problem, and found several possibilites. The shocks in the rear are original, but would not cause this issue. I got 4 new BFG Ultra High Performance Traction T/A tires on the car, and the 4-wheel alignment is dead-on. The car does not pull or anything.

The brakes are also brand new, all around. No pulsation in the pedal.

I've had the car up in the air, absolutely NO play in any ball joint, bushing, pin, tie rod, or anything under the car. It's all tight.

Which leads me to the driveshaft. I have had the driveshaft out 3 times. The Bently manual says to try rotating 180 degrees @ the splines, and also maybe 90 degrees at a time at the final drive flange at the pig. Did this, didn't help. Second time I had the driveshaft out, I replaced the flex disc @ the rear trans. flange, the center carrier bearing assy., and lubed the splines. I also checked the u-joint play and center splines, no excessive play noted. I do have some play in the rear trans. flange in the tail piece of the transmission, which to my understanding there is a repair kit for? It seems a bit sloppy to suit me. But I tried the new parts, no change.

Third time I took it out I tried another series of rotation and I also aligned the entire drivetrain with precision instruments per the Bently manual. After installation and a test drive, the vibration is still there.

I also get the clunky downshifts, and when I go into reverse, there is also a large clunk. The rear axle shafts appear to be straight, and as I said, no bearing problems iminent. There are no missing balance weights on the driveshaft. Center splines are lubed well.

Before I go ordering a $700 driveshaft assembly, is there anything else I should do? Are these drivetrains THAT fussy? I suppose that's a good thing, but what a pain in the ass.

Comments/suggestions would be greatly appreciated. I HATE F!@#%* vibrations.

441tech

fastshivy · 06-25-2006, 08:32 PM

wow I hate vibrations too!!! You might try having the shafts balanced..locally or somewhere like Dennys drive shaft. Could the rotors be out of balance? Some mfgs use spring like weights in the cooling fins and they sometimes dislodge. Do you know someone you can swap tires and wheels with for a test drive? Issues I have had like this usually turn out to be poorly balanced tires. The Hunter road force balancer is the best way to go.Just some thoughts... Good Luck

325isBaby · 06-25-2006, 11:01 PM

I've seen aftermarket wheels do this, they balance out every time but being lug-centric causes vibrations...or some occasionally tires with heavy spots can do this...just throwin it out there vibrations are difficult to diag even when you have the car

Hootie · 06-26-2006, 08:54 AM

Is it between 55 and 65 at a particular gear? If you downshift at that speed, is the vibration still there?

My old vibrations came from a crappy set of tires. 80-90mph the car would shake, outside that range it was fine.

441tech · 06-26-2006, 12:22 PM

It's the GM 5-speed auto. Tires are not the issue. I may have a bent wheel, which I will have to isolate maybe by rotating the spare around the car until the noise changes--if it does at all.

Can the '99 GM 5-speed auto be reprogrammed for smoother downshift?

Also, is there a repair kit for side-to-side play in the tail flange of the trans.?