lindatr4

Thank you for the info Peter

Does your plug tighten down to the shoulder? I was half tempted to fit a washer of some description but then found it would not tighten fully because of the taper.

Thank you Bob. My intention is to follow the above advice on GB40 gear oil on the basis that other owners (such as your good self) would not risk any other. I have spoken to many guys whilst on the show circuit that learned their apprenticeship on TR4s...would be interesting to hear their take on it.

Much has been said (and written) on the subject of the correct gear oil to use. I took the following capture from the original TR4 manual It would appear that Hypoid EP90 is the "go to" for both gearbox AND rear axle...now I am confused.com

Thank you Roger. Penrite GB40 for me it is then. Almost tempted to fill with EP90 GL4 but sounds like that would have been ok too

Hi Roger As someone that values your opinion highly, it is educating to read your comments. On a learning curve regarding correct gearbox oil, I understand the need to use a GL4 as opposed to a GL5 now. Would an EP oil cause a lasting damage of a similar type?

Looking to replace the drain plug on the gearbox with a magnetic type and a few questions have arisen. Am I correct in that the threads need to be tapered? Is the drain plug and filler plug interchangeable? I have found the cheapest plug to be this one https://www.overdrive-repairs.co.uk/product/magnetic-oil-drain-plug/