61 Rear End Advise Please

[blown240]

I noticed that the rear end of my 61 Panel started whining on the freeway. I checked the fluid, it was low, so I filled it up. Over the next couple days it leaked out. At lease as much that will leak out the pinion.

Should I just go thru the rear end I have, or swap in another?

I would really like to get rid of the 4:11 gears if I swap out the diff, but I for sure want to keep it 6 lug.

A 63-70 12 bolt may be my best bet, but not sure on the gear ratios. a 3:73 or 3.90 would give me a nice freeway gear. (350/700r4, 235/75/15 tires)

Money is a big concern, so I need best bang for the buck...

So do I repair the Eaton, or swap a 12 bolt?

[62stepside longbox]

I got rid of my eaton and replaced it with a 12 bolt from a 71-72 (so it's 5 lug) but doing one from a 63-70 would be the same install. they are great because you can usually find them in the $100 to $200 range. One thing you will have to do is cut the mounting brackets off the axle and weld them back on in the correct location for a 60-62. You will find with the 12 bolt that every single part is available in the aftermarket which is quite the advantage. If you decide to stick with the eaton you will need to remove your third member, remove the carrier, remove the pinion, (press off the old bearing and press on the new one while shimming it properly to get the correct pinion depth ( if the bearings are bad)), replace the pinion seal, then install the pinion back in, set the correct bearing preload, and reassemble the entire thing. All of this will most likely need to be done by a specialist ($$$) unless you feel you can tackle it yourself. So taking all of thing into account it might make more sense for you to go with a 12 bolt. Just my opinion

[blown240]

Thanks for the reply!

There is no way I would try to setup the gear mesh myself, and I don't have that kind of press. 200 for a 12 bolt is great, and I can easily weld in the mounts!

Sounds like a 12 bolt is the way to go!

Thanks again!


Any chance the brakes from a 61 rear end will work on the later 12 bolt? I replaced EVERYTHING inthe brakes a year ago, and would really like to reuse them.

[62stepside longbox]

Originally Posted by blown240

Thanks for the reply!

200 for a 12 bolt is great, and I can easily weld in the mounts!

Sounds like a 12 bolt is the way to go!

Thanks again!

Your welcome, they really are quite reasonable, just checking on my local classifieds there is a few truck 12 bolts with the cheapest being 125 and the most expensive being 250.

Originally Posted by blown240

Any chance the brakes from a 61 rear end will work on the later 12 bolt? I replaced EVERYTHING inthe brakes a year ago, and would really like to reuse them.

I doubt it but I can check since I have a 12 bolt and an eaton ho32 laying around.

One thing that is nice about squarebody 12 bolts is that they have wider brake pads. if you wanted to you could steal the backing plates and brake assembly's from a squarebody and bolt them on to an earlier 12 bolt, that's what I did. But there's no need to use an earlier 12 bolt, if you wanted you could use an entire squarebody rear end but you would need to buy brand new mounting pads to weld on since they came factory with leaf springs.

[blown240]

Aren't the square body trucks all 5 lug? I really want to go 6 lug drum, because that's what's in the front. I have power drum and it stops pretty good.

[LostMy65]

The 4x4's were 6-Lug

[62stepside longbox]

Yes I forgot to include the part about the 4x4. If you can't find a squarebody 4x4 rear axle then you could do what I did, take the backing plates and brake assemblies from any squarebody 12 bolt (even a 5 lug) and bolt them onto a 63-70 12 bolt. You don't need to do this brake mod, I just wanted to so I could get wider brake shoes and drums.

[LostMy65]

I was searching to see if I could find the thread where it talks about all the different 12-bolts. Can't seem to find it.
But, here's a couple threads that have added information :
http://67-72chevytrucks.com/vboard/s...d.php?t=445406
http://67-72chevytrucks.com/vboard/s...d.php?t=389811
.
What I found a consideration was the lug count, spline count, and overall width of the axle. I went with a 65 to early 70 12-bolt because I wanted 6-lug, the newer spline count, and the same width.

[blown240]

Great Info! Thanks so much for the replies!

Time to start looking for a 12 bolt. Preferably 65-70 with a 3.73 or 3.90. And posi is always nice!

[LostMy65]

The 12-bolts Stock to the 65-70 trucks I think step from 3:73 to 4:11.

[jtrichard]

Pull the yolk off and reseal it so you have some time to round up the parts you need

[blown240]

Not a bad idea, how do you do that on an Eaton?

[Clyde65]

It's easy to reseal, I did it in my driveway. I got my gasket set from Napa I believe and power washed the rear, then took it apart.

[Brad54]

It's a little bit more of a hassle to find, but for '60-'62, the Dana 44 was an optional rear end in Chevy coil over trucks, and it came standard on the GMC leaf spring trucks.

I've got one in my '62 Suburban, and found a spare (The original housing on mine broke and I spun a carrier bearing and snapped an axle... had that one replaced, then found a spare).

The advantage of the Dana 44 is that it is still in production today--and is in fact the longest running differential in the country--it was found in early '50s Studebakers, IRS Corvettes, Vipers, Explorers, Jeeps of all varieties, and even industrial vehicles like street sweepers.

Rebuild kits are plentiful, and so are used posi differentials. I found a Jeep take-out dif for a 3-series gear set; a common occurrence because a lot of off-roaders go to numerically higher gear sets.
I've got 3.42 gears in my Suburban.

If you go with the later 12-bolt, you'll not only have to move the mounting perches, you'll also have to weld on the panhard bar mounting bracket on the axle tube. Not a big deal, but keep it in mind.

-Brad

[blown240]

Interesting. How do I know if I have a Dana or Eaton? Would a pic of the cover help?

[blown240]

Here are a couple pics of my rear diff:

Is it an Eaton or Dana?


Thanks!

[62stepside longbox]

Dana 44

[62stepside longbox]

And eaton ho32
*edit: I didn't notice the pictures you just posted while I was writing my post. It's definitely an eaton

[blown240]

Bummer! Oh well, still looking for a 65-70 12 bolt with a 3.73....

[jtrichard]

Originally Posted by blown240

Not a bad idea, how do you do that on an Eaton?

This should help it is not an eaton in the video but its all basic

https://www.youtube.com/watch?v=15zHpz6Zx8c


And Ill take a dozen glazed LOL........ I miss the Helms trucks

[LostMy65]

My 65 is on a 62 frame.
Here is my swap to a 12-bolt :
http://67-72chevytrucks.com/vboard/s...62#post7355862

[blown240]

I have been looking for a 12 bolt, and I found a 3.73 posi from a 70 Blazer. Are the Blazer rear ends the same width as my 61 Panel?

[Captainfab]

The Blazer differentials are no different than a pickup differential. Is the Blazer a 2wd or a 4wd? 1970 was a transition year for 12 bolt differential widths. The early '70 12 bolts were 62" wide as your Eaton HO32 should be. The mid/late year 12 bolts were 63.5" wide. So it's hard to say without actually measuring it.

[vince1]

I got lucky once with a cheap repair to a leaking pinion seal in a Jeep. The nut had backed off and just replacing the seal and tightening on a new nut made it good again.

On another one that was making noise after having run low on oil I just changed carrier bearings. They (carrier bearings) are the first to run dry as the crown will continue to throw the last bit of oil to the pinion until it runs completely dry. I still have to top that one off once a year because of slow leaking pinion.

Just changing bearings and keeping track of the shims should be OK without doing a compete set up, or should I say that has been my experience. Others may argue otherwise.