Hi everybody, i read the sticky on tcase fluid change ran down to walmart grabbed a bottle and changed it. I was looking around on here at the conversations and back and forth on GL5 and im just looking for some input. I cant find anywhere on the bottle about it being GL4 safe. I'll swap it out if it needs to be done. Thanks for any info.

 

What weight and brand are you talking about? I used to run a GL6 in the diffs and t/case and switched over to Mobil 1 in a 75W/140 along with 1/2 pint of Lucas Stabilizer in the rear diff to keep the Detroit happy.

 

Its supertech 85-140 the same stuff in the sticky. Thanks

 

Go for it, works well in hot weather and no ill-effects in the cold weather we have in Colorado.

 

Thank you.

 

That stuff IS GL-4 and GL-5, so you are safe.
GL-5 that is NOT also GL-4 rated will eat brass, we have brass inside our diffs.

 

Thanks, one of your old posts said NOT to use GL5 unless it was GL4 rated and i couldn't find anything on the bottle so i decided to ask.