I have had a 69' Chevy truck 12-bolt squirreled away for 2 or 3 years. Now I have a need for it and drug it out, setting it on a pair of stands. For no reason I took a lug in hand and started to spin it and found it locked up tight. It took a 4 ft. cheater between the lugs to break it lose, with a muffled pop it began to turn. But not easy enough to do by hand. I continued to turn and it got easier and easier, but still thinking the worst I pulled the cover. I found only gears and oil. No rust, or broken bits. Continued to spin a few minutes more and it seemed right as rain. Now after a month, I get back to it last night. With Christmas, and all it hasn't been touched. Again it was locked up, but it took very little effort to get it going again. Nothing like it did a month ago. Here is my question, do I install and hope it just needs to be driven to get all it's parts lubed up and free. Or should I expect a rebuild in it's future?
I am not familiar with chev 12 bolt but I would remove the cover and lube with some differently grease. If it is a lockup be sure to use the right lube,
If the center section is clean, check the outer axle bearings. Dumb question, does it still have the drums on it? Could be the brakes are stuck.
yep if it has brake drums on it ,i would think thats where the problem is. some of the drum/shoes can rust together and be a REAL P.I.T.A. to break loose. good luck
No the drums are off. Outer bearings sound like a good idea, cheap insurance now rather than later when it's under the truck.
it doesnt take shit to pull the carrier on a 12 bolt,you should pull it and check the side berring and then the pinion berrings,they are easy to tear down and it is easier now then on your back under your ride
Yes, they're easy to pull apart, but once you do be sure to keep track of shims on each side or you're in big trouble! And if you get into the pinion bearings you'll need a new crush sleeve, and then you'll need to make sure the pinion depth and lash are all set properly again. A GM 12 bolt is easy to demo, but not so easy to get it all back together right when you start messing with the bearings in the 3rd member.
Axle bearings probably will not cause it to lock up, unless they are rusted...but that would be unusual. But, before spending money on the rear, pull both axle shafts out to see if they are peeling where the outer bearing ride on. That is common on hi mile rears. If this is a 69 C10 rear, the only axle shafts that will fit are 64 through 69 pickup. If the pinion nut is loose, or if there is play at the pinion, there is a good chance it will be a howling gear set, even if you reset it all. One more thing is ratio; if it was a stick, it probably has a 3.73 which is not too good without an O/D. There is a chance it could have the 3.07 though.
I had same issue with a 72 C10 12-bolt I was putting under my 64 C10. I had it on stands, pinion down, and put a gallon of WD40 in the pumpkin and let it set for 14 days, turning it every day. Then drained WD40 for 2 days, filled with rearend oil, rotated it for 4 days, then drained it again, sealed cover, and filled and installed under truck. Never had a issue again. And it was ulmost impossible to turn before I started.
Hope it works for ya. The 12-bolt I had had been laying in the weeds on the ground for 10yrs. And we get from snowy single digit to 100+ degree weather here. I thought it was a goner. But it was a 3.08 posi so I wanted to see what would happen. I lucked out..
I'll need swap over to 3:08 in a 65 C10 (if it comes home in a couple of weeks). I'm sure it's a 3:73 rear now... 235 L6 / 3 on the tree. I even considered going five lug just to open up the search for donors. Anyone have the saddle and panhard dimensions from the 63 to 72 axle housing documented?
64-69 C-10; same width, same P-bar. 64-72 C-10 chev, will all be a bolt-in swap, but 70-72 is about 1.5" wider which helps fill in the rear wells a bit better. 70 will be the last 6 lug in 2wd, but is that wider rear. If you don't mind swapping perches by cut/weld, a later 70s through 87 C10 (5 lug), or go with K-10 for 6 lugs; these later ones will usually have better highway gears. Gears can be found in 2.76 and around 2.50. (These are large pinions that won't fit into your old 65 housing; the gear is too fat). However, these 73-up rears won't have a boss with the stud for the P-bar on the center casting. Easy way is to copy, or get, a 60-63 welded-on P-bar bracket mount that was on the right axle tube. You will have to lengthen your 64-72 P-bar to reach it.
Good grief guys - forget WD-40. It got that odd name 'cuz it took its developer 40 tries to make it. Use BLASTER. That will loosen up a virgin (rear end). Sure glad I found Blaster. Oh-it smells, so just like people medicine, it's gotta be good. Murf
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