Finally getting the ole 76 Dart Sport up and running after years of mothballs.

Task: change the gearbox lube. Turns out I have a Tremec A390 instead of the more usual A230. Curious...any advantages of one over the other?
Pain: no drain on the A390, but the toploader leaks less, yes????

Also: looking at all the gearbox lubes MOST say GL4-GL5. suitable for GL4 gearbox applications. I did read the other thread about the GL 5 issues with synchros.....so I made a call over to Passon Perf.

"they" feel that the GL4-GL5 is fine to use, and won't cause a problem. Just anothe opinion I guess, but they know a heck of a lot more than me.
ATF was in the box when drained.

Go back to ATF, or go to your local parts store (NAPA I know has it), and look for the big white bottle with the label marked "Manual Transmission Oil"...it's GL-4 and works fine. In a pinch I have used 80-90W on the little bottles but it's GL-5 and I've noticed that it's a bit slickier if doing power shifting vs. daily driving.

Nice to see you have the A390 3spd, never have seen an A-body with one installed, typically the late cars got the A-230.

-D.idiot

Is the A390 any better than the A230? other than top vs sideloader?

I think it was a bit more heavy duty than the A-230. What is your transmission code on the fender plate? D-##?

-D.Idiot