Gearbox grinding

MH999 · Post by **MH999** » Thu Mar 18, 2010 10:40 pm

G'day about a week after buying my gpx I noticed a grinding noise when the revs between 1500 2000 rpm ,it only happens in 1st and 2nd and softly in neutral with the clutch out.Is it the thrust bearing?and if it is do I have to replace it straight away and replace clutch while the box is out?My clutch is working fine it doesn't slip or shudder can I just leave it for a couple of years or will my box go bang soon. Or could it be something else all together.Thanks

FTEvolution · Post by **FTEvolution** » Fri Mar 19, 2010 7:10 am

If it is indeed the clutch then you should replace the entire unit. But if it's only doing it in 1st and 2nd + neutral (and not in 3-5th) then I would guess that it isn't that.

Grinding sounds like maybe chipped/broken teeth? I wouldn't be surprised. Perhaps synchros. Do you normally thrash it in 1st - 2nd?

Post by **vipfto** » Fri Mar 19, 2010 8:33 am

maybe one of your belts pullys or tensioners rather than clutch i think

MH999 · Post by **MH999** » Fri Mar 19, 2010 7:32 pm

FTEvolution wrote:If it is indeed the clutch then you should replace the entire unit. But if it's only doing it in 1st and 2nd + neutral (and not in 3-5th) then I would guess that it isn't that.

Grinding sounds like maybe chipped/broken teeth? I wouldn't be surprised. Perhaps synchros. Do you normally thrash it in 1st - 2nd?

. It will also
make the noise if I'm in a high gear at low speed.So if I'm in 4th gear and only doing 40 kmh and accelerate between 1500 2000rpm it makes the noise but mostly accelarating in 1st and change into 2nd at 3000rpm revs drop then noise.I doubt it would be the syncros cause gear changes are good.

nicholas · Post by **nicholas** » Mon Mar 22, 2010 9:32 pm

Mine does that too; have been told it is the thrust bearing.

Mechanic says there isn't much point doing anything about it until something breaks... would be interested to hear if anyone has had this issue and gotten it fixed?