Which oil in 4 synchro gearbox with Overdrive?

[iani]

Can anyone who has overdrive fitted please tell me what oil they are using in it and, ideally, how many miles they have covered?

There seems to be a lot of conflicting information out there, oil manufacturers such as Millers will tell you that their EP90 GL4 spec' product is correct but Laycock documentation says to use 20-50 and to avoid EP. I'd rather base my decision on real world experience if it's available.

thanks

Ian

[Moeregaard]

The Laycock OD I had in my Healey 3000 used SAE 30 motor oil. When I bought the car, someone had filled it and the gearbox with 90W gear oil, which was coming out all over the place. I'd stick with the manufacturer's recommendations.

[iani]

This is the problem though, the gearbox manufacturer says one thing and the OD reconditioner, a long standing and reputable company says another. Obviously as both components share the same fluid this is a bit difficult to achieve, hence my asking for long term experiences.

Ian

[abowie]

I'd ask the reconditioner why they recommend a different product to that suggested by the manufacturer.
If they provide a good answer and stick to their guns I'd go with their recommendation I guess as they're the ones providing the warranty.

[christopher storey]

It depends which box you are talking about. The Jaguar all-synchro box must have EP oil ( Contrary to the misprint in the manual ) . The Moss box uses 30 weight engine oil. I would not risk the gearbox for the sake of the OD, because if you do not use EP where it is specified, you are likely to get excess wear where there are high point loadings or shear forces