What kinda diff?

[Senor_paco]

I bougght a differential set off a guy, and need help ID-ing it. I'm not that familiar with the different posi/auburn types. It has no clutches. Inside it has what appears to be a small(1" or so) flywheel with psring loaded cams, kinda like ditributor weights. It appears as though when the wheels turn differently, this flywheel starts spinning, and when the cam weights flip out far enough, they hit this big metal tang that appears to lock the sides together. It is a 12 bolt, but i forgot the manufacture date info off of it.

Oh, and a couple of other things. Can I get a "short" install kit from Jegs to install it?

and another. I had it in a 5gallong bucket, and it got wet. I have to have the carrier bearings replaced on the outside, but what can I use to clean the internals? any help is appreciated.

[Senor_paco]

Oh ,yeah, It's a 4.11

[Hardrock2]

Hey Paco,

Welcome!!

Sounds like you have a "governor- lock". From about mid 74,75
on up GM used these little gems in all the 1/2 ton 12-bolts, (some 3/4 tons used them too) when a "locking"differential was specified. Definitely not for any hard driving, or HP applications, though! They look like a swiss watch inside, but unfortunately, they don't hold up nearly as well!!
Their claim to fame? when one wheel momentarily looses traction,
(snow, ice, gravel, etc.) then bites again, they leave all kinds of
shiney little "watch" parts in the bottom of the case!
Might be a good idea to quiz a few more board members before
spending $$$$$$ on this setup. JMO!
When searching for good parts, most times earlier is better than
late model. From what I remember, GM used the "good" clutch-type posi through '72 and carried over into alot of '73 and a few '74 1/2 tons. After that they all got the GOV. LOCK. 3/4 tons
went from lockers to GOV's about then too, I think. Although, I've
seen 3/4's with either from '73-up. Hope this helps.