Clunk on shift

[ArtClassShank]

Hey all, I've been experiencing a clunk whenever I clutch in and move the shifter. It can be prevented by a delicate gas and clutch balance, its pretty hard to shift smoothly all the time. It's not present when you throw it in neutral after acceleration. Does not clunk when shifting through the gears while stationary. Similar clunk with on/off throttle. As the weight of the car shifts, think that might just be subframe bushings.


Sometimes its a double clunk clunk, sometimes just once. I also heard a terrible clunk while clutching in at parking lot speeds at around 1500RPM.

Heres a video of the car on a lift:

http://www.youtube.com/watch?v=y0mV7SAv-_s

Here's a video of the DS U joints, I think they're ok.

http://www.youtube.com/watch?v=crnlk1tGTkU

The guibo is less then a year old, and there doesn't seem to be much CSB wear.

So, Diff Backlash? Diff Bushings?

The subframe bushings and RTABs are original, likely candidate? Seems way more driveline related then bushings tho.

[Ocell]

Mine does the same thing. I'm GUESSING it's something to do with the pinion, maybe loose. I've got an open diff, and I wanted an LSD anyway, so I'm just driving it as-is until I swap in an LSD. If you don't figure your issue out in the meantime, I'll try and update you on whether it's my pinion after drop the old one and check it out.

But if you don't want to wait, I'd drop the diff and check the pinion flange for play.

That's my guess anyway. Hopefully someone else can jump in with an educated answer.

[Wanganstyle]

rear sub frame large bushes are gone on each side

[mr.vang]

rear sub frame large bushes are gone on each side

How you been? Still looking to buy BMW LSD diff?

[Ocell]

rear sub frame large bushes are gone on each side

I've personally ruled that out since all new Condor bushings were put in right before I got the car.

Unless the bolts have come loose or something. I'll double check that.

[ArtClassShank]

rear sub frame large bushes are gone on each side

What makes you say that?

I don't doubt it, just wondering what tipped you off.

[Wanganstyle]

What makes you say that?

I don't doubt it, just wondering what tipped you off.

Because racing?

Our car vibrated one side cross member hardware completely off in 14hours of endurance racing. It made a very interesting klunk. Only three points connect the rear end to the body; they are all huge mounts.

1. Rear diff mount
2. Left subframe bush
3. Right subframe bush.

The diff is solid bolted to the subframe with 4 large bolts.




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[jlevie]

Bad subframe bushings, a bad differential mount, loose differential, bad drive shaft, or a worn differential are all possible causes. Further investigation will be needed to determine the cause(s).

[Joerdan23TN]

It sounds like we are experiencing the same issue. From what i understand my issue to be, yet to be 100% determined is a bad CSB, or front u-joint.

Keep us informed as to your solution.

[Ocell]

I swapped my diff and I've still got the clunk. I'm thinking maybe it's the u-joint on the drive shaft, too.

[Balleristic31]

I've had this same issue for a long time an have also ruled out diff, and all rear bushings. My last idea is u joints but driveshafts are pricey

[ArtClassShank]

I've had this same issue for a long time an have also ruled out diff, and all rear bushings. My last idea is u joints but driveshafts are pricey

Indeed they are.

I found they're cheapest on this site.

http://www.wholesaleimportparts.com/BMW_Drive_Shaft.php

Anyone have any experience? Seems to have decent reviews overall.

[Northern]

I get the same clunk. I have some shitty offbrand poly bushings/mounts which do not line up properly. I installed some diff spacers to make up for the misalignment. It's much better for now, but over the winter I'm going to replace them again with condor or revshift bits.


I would check to see if your condor mounts are in the right way, and if they're subframe risers, then check to be sure there are the [correct] diff spacers installed.

[ArtClassShank]

Bumping this thread, I replaced my sub-frame bushings and I still got quite the clunk. The on/off power clunk is gone, so thats good. Now I'm getting tons of differential noise, and the same old double clunk. Thinking that my axles are worn. Possibly the diff as well.