Noise at low speeds, forward gears

[evilnickwong]

I'm having a noise coming from I assume somewhere in my driveline.

1) I can only hear it at low speeds, perhaps it's drowned out by road/engine noise at higher speeds.
2) It's a noise that kinda goes "klok klok klok" and goes slower as my car moves slower.
3) Once the car stops, the noise stops too.
4) This happens in forward gears only. When I shift to reverse and move at the same low speeds, no noise.
5) The noise is there regardless of whether the clutch is engaged or disengaged.

However, other than this noise, there are no issues with the gearbox, e.g. no funny whines, shifting is fine and etc.

I had all the gearbox oil seals replaced the other day (problem existed before this too) and while it was up, I noticed a few tiny cracks in my guibo. Could this be the cause? I thought guibos only caused clunking noises when shifting gears, which I do not have.

[jlevie]

Check the guibo and the mount of the center support bearing for cracks and/or tears. Cracks or tears in the guibo mean that it needs to be replaced. A torn mount CSB mount means that it and the drive shaft need to be replaced.

[nickpdx]

My e30 makes the same noise - sounds like it comes from directly underneath the shifter. Replacing my transmission fluid with Redline MTL drastically cut down on the noise, but I can still hear it, albeit much quieter. I haven't had a chance to check out anything else underneath the car yet being at university without a place to work on the car.

[evilnickwong]

jlevie: I'll check that out as soon as I can get the car on a lift, thanks. Are these a known cause to the noise?

nickpdx: Yea, the noise sounds like its right under the shifter area too. If it's just the inherent noise of the gearbox, then I guess it's alright, but the thing is it only started a couple months back, I don't remember hearing it previously.

[Mike]

Does it matter when the car is cold or hot?

[evilnickwong]

Seems to happen more during first drives of the days.
When I leave for work at 8am, it can be heard some days. Then my car is parked in basement until about 6pm and the noise is also present sometimes when I leave.
But it's not as apparent later in the night or if I've been driving the car for awhile.

The main problem is that it's an on and off thing, so it's not consistent enough for my mechanic to check out either.