'64 rear differential....

[McCoyAZ]

My old truck is a 64 c10.

The parts house tells me that the '64 is supposed to have a 10 bolt rear end in it and the one I have is a 12 bolt.

They say then if it's a 12 bolt it is from a '63.

They can't seem to tell me which pinion seal I need or which U Joints I need to fix it.

So I need to know when I look for these parts, what year I should be looking at??

It was O'Reiley Auto Parts and a local parts house that couldn't tell me ....

[DPowers]

I thought they were 12 bolts up through early 80's in c10's.

[1963c-10]

yup, 10 bolts in c10s until 62. 63 went to 12 bolt w/17 spline axle and 30 spline in 65. pinion seal should be same from at least 63-72 12 bolt....thats 1/2 tons

[66Submarine]

The parts house is wrong. (Big surprise, lol) '64 had the 12 bolt; GM changed to the 12 bolt in '63.

[McCoyAZ]

Funny thing is that both Auto Zone and O'Rieley say that the 10 bolt is what is in that truck, not a 12 bolt.

Makes it hard to find parts when the parts guys don't know what they are talking about :-(

[Snailed]

Going by the year isn't the best way to do this since these parts could have been changed in the last 49 years.

Wouldn't looking under it and counting the bolts be easier? You could measure the U joints too while you're under there and get all the correct parts on the first try.

[gofastnut]

Speaking as a parts guy, As long as everything's original(not updated/changed), and a parts house has BOOKS, there shouldn't be a problem getting you these parts.

[gofastnut]

OK, This is for an auto or 3 speed, 4 speed is different. If you've got a 4 speed, let me know.
with a 3 joint drive line, all three should be the same, Precision #369
with a 2 joint drive line, both should be the same, Precision #369
The pinion seal should be a National #8460N, there's also a #5578, but my money's on the 8460N.
Hope this helps.

[McCoyAZ]

Originally Posted by Snailed

Going by the year isn't the best way to do this since these parts could have been changed in the last 49 years.

Wouldn't looking under it and counting the bolts be easier? You could measure the U joints too while you're under there and get all the correct parts on the first try.

If I had the truck where I could crawl under it and count and measure....I agree it would be easier. But it's 20 miles away locked in a garage that I don't have access to.

That's why I was hoping the parts guys had the correct information.....sadly they don't.

[McCoyAZ]

Originally Posted by gofastnut

OK, This is for an auto or 3 speed, 4 speed is different. If you've got a 4 speed, let me know.
with a 3 joint drive line, all three should be the same, Precision #369
with a 2 joint drive line, both should be the same, Precision #369
The pinion seal should be a National #8460N, there's also a #5578, but my money's on the 8460N.
Hope this helps.

Thank you very much for this.....I will see if the local parts place has any of this.

The truck originally had a 6cyl with 3 on the tree.

I removed it and put a 283 with a power glide in it. Had the original drive shaft shortened to fit the new configuration but did not change the u joints since the shop guy said they looked great....

The 12 bolt rear end is original to this truck according to the original owner.

[gofastnut]

Then, to the best of my meager calculations, those part numbers for the U-joints and pinion seal are correct.
Good Luck!

[50bomb]

I went to Napa for a differential gasket cover. Napa told me that my 12 bolt is not original to my 65 c10 and that it should have a 10 bolt. They said I had a 67 c10 rear end haha. Bunch of bs. They dont know anything now a days. If they actually looked into the books instead of their data base computer they would know the correct stuff.

[Captainfab]

The GM truck 12 bolt was first introduced in the '63 model year and used in the C10's thru the '82 model year and thru '79-'80 in the K10's and K5's. The '63+ GMC's did use the Dana 44's in the 1/2 tons which did are a 10 bolt. Both the Chevy and GMC's from '55-'62 used the Eaton HO32 differential which was also a 10 bolt, but had a drop out 3rd member.

[gofastnut]

Sorry it took so long to look at this thread again.
Thanks for that info, Captain!

[McCoyAZ]

Originally Posted by 50bomb

I went to Napa for a differential gasket cover. Napa told me that my 12 bolt is not original to my 65 c10 and that it should have a 10 bolt. They said I had a 67 c10 rear end haha. Bunch of bs. They dont know anything now a days. If they actually looked into the books instead of their data base computer they would know the correct stuff.

Auto Zone told me the exact same thing.

Local parts house said I had a Spicer rear differential..... geeeezzzzz