Bad Gearbox?

[b756]

Any ideas on a noisy gearbox,C2 1999 6 speed,when changing gear from 1st to 2nd and on decelerating from 3rd to 2nd the gears will sometimes make a loud grinding noise,happens every 10 or so shifts,the more revs the less likely the noise.

I've looked at where the gear shift linkage enters the transmission and there seems to be quite a bit of free play on the bushing.thanks for any info.(and where to get a recond trans)!!!

[ADias]

This sounds like a bad clutch - that is the clutch does not disengage completely. When this happens it is noted in the low gears and less so in the high gears.

[umn]

Any ideas on a noisy gearbox,C2 1999 6 speed,when changing gear from 1st to 2nd and on decelerating from 3rd to 2nd the gears will sometimes make a loud grinding noise,happens every 10 or so shifts,the more revs the less likely the noise.

As it happens only when you shift into 2nd (either up or down), I would suspect a problem with the synchromesh. That would be bad news :( :( :(

Cheers,

Uwe

Edited March 31, 2004 by umn

[b756]

Thanks,is the synco something that can be repaired,or does it mean a new gearbox?

[b-man]

The synchromesh cannot be repaired, but it can be replaced. I'm sure the part is not expensive at all. Unfortunately, to get to it, the transmission must be removed and completely taken apart. Yes, I mean completely taken apart so, that would be very, very expensive.

Personally, I wouldn't worry about fixing the problem. It's hard to believe but, it's really not a big deal and what seems like more wear (the crunching or grinding) really isn't. The only time that it is more wear is if you are very slow to engage the gear and sort of hold it half in and half out while it is grinding. You may also notice that the problem is more noticeable if the car isn't warmed up, or vice versa.

FYI, most real race cars (as opposed to street cars put on the race track) have non-synchromesh transmissions. They grind or crunch every time a gear is engaged.

When transmissions start popping out of gear is when you need to worry.

b-man

[JDavis]

The clutch post makes sense too. You may want to look at the clutch.

Edited April 1, 2004 by JDavis

[boelem_b]

The synchromesh cannot be repaired, but it can be replaced. I'm sure the part is not expensive at all. Unfortunately, to get to it, the transmission must be removed and completely taken apart. Yes, I mean completely taken apart so, that would be very, very expensive.

Personally, I wouldn't worry about fixing the problem. It's hard to believe but, it's really not a big deal and what seems like more wear (the crunching or grinding) really isn't. The only time that it is more wear is if you are very slow to engage the gear and sort of hold it half in and half out while it is grinding. You may also notice that the problem is more noticeable if the car isn't warmed up, or vice versa.

FYI, most real race cars (as opposed to street cars put on the race track) have non-synchromesh transmissions. They grind or crunch every time a gear is engaged.

When transmissions start popping out of gear is when you need to worry.

b-man

What is wrong if it starts popping out of gear? I get that in 2nd gear. Initially I thought it was just my bad shifting, but it happened with a friend of mine too and it has been happening more often. I asked the OPC at the last service and they said it was a small adjustment, but it didn't make any difference. (996 C4 2002, 45000 km.)

[Dennis C]

I also get the occasional grind, which I believe is a synchro issue. I find that if I'm careful, I rarely get any grinding at all. Rev matching can help with this, but not always. I find that if I "baby" it a little between first and second gear, it almost never grinds. It happens more often downshifting between 3rd and 2nd. It's even more difficult if I skip 3rd and go from 4th to 2nd. I've learned to manage it pretty well, but I believe that ultimately I'll have to have my transmission rebuilt and have this issue addressed. No rush, but that's the way I believe it's headed.