Dana 24 Oil Change.

[WestCoaster]

I finally got my 72 running and wanted to change the transfer case oil. The truck was just a roller when I bought it, so unknown about the last time the transfer case oil was serviced. I've read that these used 50w engine oil. However, none of the auto suppliers around me have 50W unless they order it. I was wondering if anyone has used 20-50w as a replacment. Plus it's readly available.

Thanks.

[1972hiboy]

Ive never tried 20w/50. 50w is what everybody has said to run and it does seem to be the right viscosity to run, When I got my truck i changed the transfer case and differential fluids and just dumped 80/90 in them. They havent died yet but im probably losing a mile or two per gallon.

[eggman918]

After overhauling my Dana 24 I used synthetic 75w/90 gear lube in it and after more than 4 years it seems happy.

[averagef250]

The 24's big problem is lack of lube to the upper pocket bearing. I always had way better luck with 90WT gear oil than 50 WT motor oil.

I got rid of the 24's, but if I still had one I'd go with Steve's method and use synthetic. Synthetic won't hardly let anything wear and won't break down at high temps.

Something the Dodge guys figured out with 1st gen Getrag 5 speeds was that they run extremely hot under load. So hot that will cook the Dodge recommended oil in no time. Guys started playing with synthetics and found the thinnest synthetic oil you can run in them works fantastic. The synthetic doesn't care if the tranny temp is 350 degrees and the thin oil gets down inside the hard to reach bearings better than the thick stuff did. I run 5W30 synthetic in one with 301,000 on it. Enough proof for me that it works.

Another trend I've seen in automotive drivetrain is using sealed ball bearings instead of open. The concept is that bearings are sealed with good lube for life and the oil inside the case is just used to cool the bearings. Toyota slowly implemented sealed bearings in their stickshift transmissions during the 90's. The lifespan of the bearings increased dramatically. The 24 is all ball bearings inside. I've put several together for others with sealed bearings now and no issues at all, but you still need to worry about the pocket bearing.

Whatever oil you run, use synthetic in the 24. It will probably leak like a sieve if you don't put new seals in at the same time, so something to consider before buying the expensive stuff. Synthetic will leak right past seals that will seal dino oils.