Driveline clunking?

8

88'325i

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#1
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#1
Sorry if i started my stay on a bad note, hopefully you guys can help me with this.

88' 325i 4dr, 4spd auto, all completly stock.

Something is up with the driveline, and i'm just curious. It has been this way for the last 10 years. When coasting on the highway, and getting back into the throttle, the driveline clunks somewhere (20% or 80% throttle, doesnt matter but the clunking gets louder with more throttle). This makes me think that the driveshaft has excess play in it.

The next issue is when in town, on the 2-1 downshift (when the tranny downshifts automatically), i get a clunk. Bushings? or what?

Thanks,
 
E

epj3

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#3
Sounds like a U joint or something in the diff. A flex disc/center support bearing usually happens during initial acceleration. When the driveshaft spins fast enough (IE above 10 mph), it acts as a gyroscope (the same reason a Top can spin and be so stable) and usually can't clunk or move too much.
 
xLibelle

xLibelle

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#5
So i finished the tranny swap this weekend, and my auto always had that came clunk exactly as you describe... but it was definetly tolerable.
Since i changed the tranny and front half of the drive shaft (only two items changed that would be a cause) the clunk is even more worse.

The same highway torque clunk is still there in the same way but put it in a lower gear at crawling speeds and tap the gas to lurch the car it makes a clank sound.

my guibo if perfectly fine and i thought the UJ on the drive shaft was ok, but now i dont know. i went under the car, put it in gear and tried to rotate the shaft but i cant figure it out. so i finish all that work and still my car is going into the shop to trouble shoot the thing.

with a close enough look, jeff, the problem could come from anything between your tranny output to the wheels. my guess is that you would have to lock down each piece of the drive line and try and reproduce it by hand to see exactly what it is... or bring it to the shop like i will. :-/

anyone with ideas on how to find the problem?
 
E

equate

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#6
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#6
One thing I found on my new m3, I can get a good clunk every now and again, but it was from me being to quick on the clutch or not pressing it in all the way. Especially if your not used to driving stick make sure the clutch is in all the way when you shift or you will clunk it. Probably not your guys problem but a fyi for everyone.
 
jrt67ss350

jrt67ss350

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#7
xLibelle said:
So i finished the tranny swap this weekend, and my auto always had that came clunk exactly as you describe... but it was definetly tolerable.
Since i changed the tranny and front half of the drive shaft (only two items changed that would be a cause) the clunk is even more worse.

The same highway torque clunk is still there in the same way but put it in a lower gear at crawling speeds and tap the gas to lurch the car it makes a clank sound.

my guibo if perfectly fine and i thought the UJ on the drive shaft was ok, but now i dont know. i went under the car, put it in gear and tried to rotate the shaft but i cant figure it out. so i finish all that work and still my car is going into the shop to trouble shoot the thing.

with a close enough look, jeff, the problem could come from anything between your tranny output to the wheels. my guess is that you would have to lock down each piece of the drive line and try and reproduce it by hand to see exactly what it is... or bring it to the shop like i will. :-/

anyone with ideas on how to find the problem?
Click to expand...
The increased clunk after doing the swap is probably due to the play in the manual tranny. Since a manual tranny is a rigid coupling between the flywheel and the rear wheels as opposed to a fluid coupling in an auto, slop in the tranny will be much more apparent.b
 
xLibelle

xLibelle

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#8
jrt67ss350 said:
The increased clunk after doing the swap is probably due to the play in the manual tranny. Since a manual tranny is a rigid coupling between the flywheel and the rear wheels as opposed to a fluid coupling in an auto, slop in the tranny will be much more apparent.b
Click to expand...
shit
 
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