View Full Version : Differential Oil

Rick O.
02-01-2003, 10:30 PM
Are there any brass bushings, thrust washers, etc. in a '72 TR6 differential? I don't have any GL4 gear oil and I know the GL5 eats brass. Thanks.

02-05-2003, 12:28 PM
Hello Rick,
No there is no brass, it is all steel. I'm not familiar with the oils you refer to. My handbook says EP90 gear oil.

Alec graemlins/cheers.gif

Rick O.
02-05-2003, 02:23 PM
Thanks Alec. GL5 is the 'modern' gear oil with vast amounts of EP (sulfur compounds) additives. Earlier hypoid oils (GL-3 and GL-4) did not contain such amounts. Our Triumph gearboxes (and trunnions for that matter) contain brass components that will be corroded over time by the GL5 additives. Thanks to you, I know I don't have any brass to worry about in the diff. If you run hypoid in your gearbox, it is advisable to stay away from GL5 (I use straight 30W non-detergent in my O/D as Laycock originally specified). Unfortunately, GL5 is about all you can buy these days at Autozone et. al. I was able to find a very dusty 5-gallon bucket of the GL4 stuff at Pep Boys that I'll use for my trunnions.

Gary Pope
02-05-2003, 06:27 PM
Somebody said you can use Automatic Transmission fluid in your old LBC gearbox (that red stuff).

Can Anyone verify that ?