HO72 Gear Lube

[18436572GMC]

Just like the title says what gear oil should I run? Also about how much does it hold? I figure any GL-5 between 75w90 and 85w140 should be fine but want to be sure.

[c20pickup]

i used regular gear oil, 75-90 i believe. I pull the plug and filled it until it came out the hole.

[18436572GMC]

ttt

[heyjoe]

According to my '67 Chassis Service Manual:

Lubricate with Multi-Purpose gear lubricant meeting requirements of U.S. Ordnance Spec.
MIL-L-2105B

Below 10F SAE 80
Up to 100F SAE 90
Above 100F Consistently SAE 140

No fill capacity in print that I can find.
Several years ago, I filled my bone dry HO52 with approx. 3qts. give or take. (Beware! my memory may be faulty!). I say "bone dry" because I had the rear end apart for a carrier swap and total clean and scrub to remove metal dust and particles.

I used 80/90 GL-5 gear oil.

Hope this is of some use.

[swamp rat]

Regular gear lube, but from what i have been told if you have the no spin diff you need a limited slip additive, available at your local auto parts store.

[Longhorn 70]

2½ is in my memory for some reason. It has been a while and I want to say the brand name was JL-7??? Some red goo that my uncle used to use in semi rear diffs.

I bought 3 quarts and tried to put it all in but it was oozing out of the fill hole. I was on a slanted driveway though. Like C20pickup said, fill until it oozes out. Put the plug in and drive away.

Good luck buddy.

[Stocker]

Pretty sure 3 qt. will fill it and maybe have some left over. I used Mobil-1 full synthetic 75W-90, but any brand will do the job, and dino is okay too. I just preferred synthetic.