What Fluid for old grindy Transmission?

[hoonigan4l]

Hey guys, as far as I can tell it says use GL4. Strictly. All of the bottles I've read are GL4 and GL5 compatible.. What do you guys suggest to use? I know damn well if I put the wrong stuff it on it won't last long. I want to service it today so a speedy reply would be fantastic!! Thanks so much NICO.

PS. Also looking to service the rear diff as well.. Fluid?

By the way it is cold weather where I live. It has been ~15 - 50 degrees the last week or so..

[NolimitZ32]

Best of the best of the best of the BEST!

Redline MT-90 for trans.
Redline 75w90 for diff.

[hoonigan4l]

Best of the best of the best of the BEST!

Redline MT-90 for trans.
Redline 75w90 for diff.

Thank you Sir, for the long awaited answer. Someone was obviously not rev matching. Synchros are not in good shape. I hope this helps.!!

[NolimitZ32]

If the Redline fluids don't help, it's time to start looking for a new trans or a rebuild.

[hoonigan4l]

Yeah, I believe it will help a lot. I have been browsing used transmissions. I saw one for 250 with 97,000 !! I thought that was a great deal. With my previous cars I was used to 500-800..