Thread: 1997 Disco 4th gear grinding

Hi,

I just bought a 1997 V8i manual disco. I have noticed that it grinds into 4th gear when at high revs (really anything higher that 1500rpm). Anyone got any ideas of the problem and what is involved in getting it fixed and cost?

Thanks

Originally Posted by Ride

Just changed the fluid with some Valvoline 75w and no difference. I'm thinking it's the 3rd and 4th synchro????

I can't find any specs on Valvoline HP gear oil 75W.
What specifications are on the bottle ?
Be a little careful if only GL5 is shown, as depending on the blend, it may be harmful to the synchros.
If I was going to use a Valvoline fluid, it'd be Duragear 75w-85, although a number of people have success with a Dexron III type ATF.

Is it only crashing 2hen cold, or when everything warms up ?

Also bear in mind that the friction modifiers used in modern manual transmission fluids can take up to 800km to force out the previous additives and embed themselves into the synchro clutch surfaces for optimum shifting.
The present fluid I'm using took two to three days for all the gears to stop crashing, now it shifts as smooth as any fluid I've used, except when dead cold. In fact I get less baulky changes now than with any other fluid I've used.