thrub

What kind of oil do you put in a getrag?The manual says 5w30 sg or sg/cd rating. Couldn't find any with these API ratings in town, are there newer API ratings that work the same. Would synthetic be better.

SOOT4BRAINS

Any 5w30 should work. Synthetic is recommended. I run Redline MTL. Kinda pricey but I noticed a difference in shifting over the standard 5w30 synthetic I was running. Lots of guys use the Royal Purple fluid and like it as well.

pulltilbroke

Mobil1 5w30 full synthetic in the old mans Rag

oilcan64

amsoil 5 30 synthetic manual transmission synchromesh! 5 quarts. its not cheap but i swear by it

BearKiller

Same here; five quarts.

Factory fill is 3-1/2-quarts; most people over-fill to five-quarts; there are more ways to accomplish the over-fill than there are to skin a cat.

Whichever method you choose to over-fill, I strongly suggest you choose one that incorporates a dip-stick; as, when you just dump the extra down through the shifter or a high PTO bolt-hole, you leave yourself with no means of monitoring it's level.

wannadiesel

If it's stiff shifting, try a trans oil like Royal Purple Synchromax or Redline MTL.

If it's a hard working truck, keep in mind that these will run a little hotter than Mobil1. A tow rig should use that and learn to be patient.

freight train

When I still had my getrag I used RP Synchromax. I liked it. I put the extra qrt in the top side cover bolt hole.

big stinky

I run 10-50 synthetic, 5.5 liters. Had royal pee syncro max, but it was real noisy.

12valve@heart

I like a little wider range of protection so I use Castrol Syntec 5W50 synthetic in mine.