Loud noise through 3rd gear when engine hot?

Hi guys,

I have a 1988 200tdi conversion 90 with an LT77 gearbox and whatever standard transfer box was on the 1988 90.

My problem is that on trips that are long enough to warm the engine up to about 50% on the gauge I get a loud noise at the top of 2nd gear, all through 3rd gear and at the bottom of 4th gear.

Up until I'm just about to change from 2nd to 3rd there's no noise and once I'm passed 3rd and well into 4th gear the noise goes away again.

The noise sounds like a sort of grinding, like a bearing without enough oil.

When I hear the noise, putting the clutch in and coasting along the noise goes away. When stationary and revving the engine there is no noise.

I'm thinking maybe that the gearbox oil level is getting a bit low and when warm (and thinner) it's not enough to lubricate the gearbox as it should. I'm going to check the gearbox oil level this Saturday on my day off.

Anyone have an idea of what this might be? I'm hoping it's not the gearbox on the way out!

Thanks in advance!
Paul

Nobody have any advice?

I checked gearbox oil level this morning and it wasnt trickling out.

Had to squirt an extra 1/2 litre of EP90 in to start it trickling.

Going on a longish drive this evening so we'll see how it goes! Hopefully haven't done too much damage already...

Only put EP90 in transfer box not main gearbox

So what goes in main gearbox?

Pauleh said:

So what goes in main gearbox?

Click to expand...

Main gearbox = ATF Dexron IID

its not going to be oil if only in a limited range ,although you need to change gear box and transfer box at least yearly ,it would be worth removing sump and seeing what free play there was in intermediate cluster ,if any adjust nut on outside rear of box with 30mm socket and bar carefully and a little at a time to just remove any free play then restake nut

Thanks everyone. Forgot to say thank you at the time