I was curious if anybody has verified that the Lucas synthetic 75w-90 works in the MT and diff. The bottle says "exceeds all GL specs" but I'm still a little skeptical. I've read horror stories while searching of people using the wrong fluids and paying for it. Would I better off getting the recommended fluids from the dealer or using something else alltogether (Amsoil, Redline, etc.)? If at all possible, actual acounts of people running with these fluids and why they chose them over the OE fluids would be helpful. Any and all help would be greatly appreciated. Thanks a lot, have a good one.

clarification: MT takes GL-4 and Diff takes GL-5.

 

it should work. I use mobil syn. 75-90 in my diff. feels alot smoother, been going with it for about 5k miles.

it shouldnt matter to much on the brand name, but the weight type should be correct.

my tranny i use oem, just cause i got a new tranny so i dont want to have any problems with the dealer, incase something goes wrong soon.

 

I've been using Amsoil 75w-90 GL-4 in MT and 75w-90 GL-5 Severe Gear in Diff for over 15K and very happy.
My 6mt is smoother in all synchro engagements, but really noticed a difference with N-1st-2nd compared with oem oil and especially when oil was still cold.

I looked at friends 'red line' catalog and they have a 75w-90 GL-4 (MT-90) as well for our 6mt's. Haven't tried though.

Lucas synthetic 75w-90 exceeds all GL....If it doesn't say GL-4 somewhere, I wouldn't use that in our 6mt's.