opinions on my differential dilemma

[bosephus]

Hi all! I have a 61 chevy with what I believe is called the HT55 rear end(drop out third member 3.90/1) that is leaking oil at the pinion.This rear end has a limited slip carrier and the ring and pinion looks fine to me(which means I don't see any huge pits or missing teeth). I also have at my disposal a 12 bolt 3.73/1 truck rear from a 65(I think) that doesn't have the limited slip and needs to be rebuilt.I dont know which way to go on this one.Are there parts still available for the HT55 and where would I find them?Is the HT55 worth rebuilding or should I bite the bullet and buy the parts and limited slip for the 12 bolt?Should I just keep adding oil and call the resulting mess rust preventionAlso,I dont mind the steep gears because i'm running a TKO overdrive transmission.Any input is appreciated(I think) Thanks

[mbgmike]

I would probably switch it out unless wanting to keep it original. Here is a company that provides us parts and maybe of some help.

http://www.sandstruck.com/landpart/drivetrain.htm

They are Manufacturers so not sure how much help they will give you.

You may want to contact Ratech
http://www.ratechmfg.com/toc.htm

[62gmc910]

the HT 55 was sold to toyota for use in the older landcruiser so parts should still be available . if you choose the later 12 bolt , parts are fairly common right up to 80 giveing a lot more ratio selection, but you will need to relocate the mounting pads and maybe adjust the panhard

[bosephus]

Originally Posted by mbgmike

I would probably switch it out unless wanting to keep it original. Here is a company that provides us parts and maybe of some help.

http://www.sandstruck.com/landpart/drivetrain.htm

They are Manufacturers so not sure how much help they will give you.

You may want to contact Ratech
http://www.ratechmfg.com/toc.htm

Thanks Mike,I figured that changing it out would be best.I dont really care about keeping it original,It just has to be able take a little abuse!

[bosephus]

Originally Posted by 62gmc910

the HT 55 was sold to toyota for use in the older landcruiser so parts should still be available . if you choose the later 12 bolt , parts are fairly common right up to 80 giveing a lot more ratio selection, but you will need to relocate the mounting pads and maybe adjust the panhard

Thanks for the reply 62GMC,I was hoping the 65 truck 12 bolt would just bolt in but I should have known it wouldn't be that easy

[K-TEN]

Personally, I'd fix it, You say that you have everything that you need. Mounting, correct ratio, posi. Why change it? Take it to a shop that knows what they are doing and get the seal replaced. Once you pull out the old seal, you'll know the p/n for the new seal. Can you honestly tell me that you'll spend less money on a swap than a seal repair? No way. Plus you have to find the new posi. Economically speaking, this swap is a loser.
The shop manual shows how to replace the seal. Some special tools are necessary, but your mechanic has done a bunch of these already.
And if you think you'll tear up your current rear end with all that horsepower, when it blows up, THEN replace it with that 12 bolt. My bet is it's going to be a Loooooong time before that happens. JMHO

[777ralph]

Why change it? you've got a rear that's already under the truck, has limited slip, and has a ratio you're OK with. Fix the seal. Done.
The other rear may need modifying to fit, has a similar gearset, no posi, and needs rebuilding to boot.
I don't care about staying original, but that seal can't be that hard to find. Seems like way less work and money.
Ralph

[bosephus]

Originally Posted by K-TEN

Personally, I'd fix it, You say that you have everything that you need. Mounting, correct ratio, posi. Why change it? Take it to a shop that knows what they are doing and get the seal replaced. Once you pull out the old seal, you'll know the p/n for the new seal. Can you honestly tell me that you'll spend less money on a swap than a seal repair? No way. Plus you have to find the new posi. Economically speaking, this swap is a loser.
The shop manual shows how to replace the seal. Some special tools are necessary, but your mechanic has done a bunch of these already.
And if you think you'll tear up your current rear end with all that horsepower, when it blows up, THEN replace it with that 12 bolt. My bet is it's going to be a Loooooong time before that happens. JMHO

I agree with you about it being cheaper and there would be nothing lost by trying to get the old seal out to ID it.I thought that when I broke the pinion nut loose I would need to set the lash in the gears again(never done this)I guess I need to get a shop manual and give it a try! Thanks

[bosephus]

Originally Posted by 777ralph

Why change it? you've got a rear that's already under the truck, has limited slip, and has a ratio you're OK with. Fix the seal. Done.
The other rear may need modifying to fit, has a similar gearset, no posi, and needs rebuilding to boot.
I don't care about staying original, but that seal can't be that hard to find. Seems like way less work and money.
Ralph

All good points,Thanks!

[jyaughn]

off topic but did you sand blast your frame to get it the clean?

[bosephus]

Originally Posted by jyaughn

off topic but did you sand blast your frame to get it the clean?

I blasted it with a HorribleFreight sandblaster,two stage compressor and about 600 lbs. of black beauty.I still get sandy feet when I wear those shoes from that day

[jyaughn]

lol so i need to blast mine

[62gmc910]

I missed the part about your axle being OK other than the pinion leak, build your self a yoke wrench basicly a piece of plate that you can bolt to the u joint clamp holes and put a 3 foot handle on it , it needs a hole in the center for the socket to undo the pinion nut , if you pull the yoke without disturbing the bearings, you should be able to replace the seal with out worrying about changing the preload much . make sure you lube the seal surface and loctite the nut . the repair should only cost you $20.00 and your time , if you somehow scrwe it up which is pretty hard you were thinking of a new axle anyway