The Stovebolt Site Forums The Shop Area Engine Shop Leaking pumpkin - rear end swap?

Hello everyone -

I am a newbie at restoration/rebuilding so I am looking for some guidance.

I have recently removed all body parts down to the frame of my 55 second series. The guy I bought it from has a rubber sealant material all over the pumpkin, so apparently it leaks if this is removed.

I have never done any rear end work and would like to try to replace the gaskets myself. How do you know what gaskets to order? How do you know what rear is even there?

Eventually I am going to upgrade the motor to a strong V8. Does anyone have any suggestions on what I could use to replace the old with (possibly used)that would work better in the long run?

Any help would be greatly appreciated!!!

Ross

Ross - if it's the original rear end, they were most commonly 3.90 .... clean it up good, check the pinion seal, redo the cover with some RTV silicone on it, and unless it's got some holes in it, it won't leak .... for awhile

the stock rear can handle V8's fine, a buddy of mine has been abuseing one with a 427 with no problems, just make sure the pinion bearing/seal are ok, which is the place it may be leaking

Bill

1stproject,

Are you indicating that the cover leaks, or the carrier (pumpkin) leaks. If it is the 'pumpkin', the axles will have to be pulled, then the entire carrier can be unbolted and new gasket installed.

This isn't a 5 minute job and requires a medium degree of skill...maybe that's why it was 'gooped' instead of properly repaired.

There are lots of folks on this site who would love to walk you through this repair. Good luck.

Stuart

Thanks for the information. I will take a closer look at it tomorrow and see if I can find where exactly it is leaking.

It is good to hear this is a strong read end. I have been reading up on what rear end could substituted and I was pretty dazed and confused after I got done reading posts from other members.

I am having a blast working with my truck. My seven year son is also having a good time helping me out. People like you both are a lot of help.

Thanks and I will most likely be back with some more questions.

Ross

Before you tear into it, get yourself a manual, or check out the Online Chevy Manuals Project http://chevy.tocmp.com/. Good info there on repairing anything on the truck. That diff is plenty strong, it also boasts a larger ring gear and axles than the later units. There is a place, Toms Rearends, that makes a conversion to 30 spline axles, using later 12 bolt side gears, if you do end up needing to upgrade. I have considered doing this myself, but am going to do some more research first. Gaskets are still being made for this diff, Fel-Pro #RDS4304.

1st -

I found a 78 Trans AM 2.56 posi rear differential off Craigslist locally and just this morning took it over to Western Drivetrain in Aurora to get rebuilt. He's changing the ring and pinion gear to a 3.08, adding a spacer and replacing bearings and if needed, the axles. Bill does good work and came highly recommended. So if you need assistance, I would look him up.

Also, when I install the new rear end, I'll have to figure out what to do with my old one from my 56 TF. Might be something to consider, especially since we're neighbors...

Well I looked it over. It appears to be leaking from the seal where the pinion housing(unsure of term) connects to the axel housing (once again, unsure of term). Basically on the drive shaft side where the pinion gears are housed and they attach to the axel hosing.

Would this be the same gasket as would be used on the back side, where the housing cover connects to the axel housing?(Fel-Pro #RDS4304 - thanks Bill!) If so, is this managible for a newbie with some basic skills and a desire to learn?

In adition...........Paul..... give me an email if you would be interested in talking more about the original rear end you are getting rid of. ([email protected])

Thanks again for all of your help!

Ross

If you are talking about a front loading pumpkin then the answer is that the gaskets are different. If it is a 3/4 or 1 Ton, the front gasket is paper thin and the back one is like a regular one.

The # I posted is the one for the 3rd member, if I can find the package (I know I've got it here somewhere! :hammering: ) I'll post the # for the cover gasket.

Ross,

I sent you an email yesterday. Go to your Stovebolt profile and you should see the email.

Paul, that rearend is also a good change for guys with the AD trucks. I have a 52 Panel with torque tube that I'm am going to take out and insert the 56 rearend. Gets rid of the torque tube and gets me from a 4:11 gear to a 3:90. So don't throw it in the junk pile!!!

1stproject,

A blow by blow on removing the carrier reads like a short novel. I have linked the shop manual for your truck so you can page through the procedure yourself and get a idea of what is involved.

Bookmark the site...it's full of good stuff, good luck.


http://chevy.tocmp.com/1955truck2shop/index.htm


Stuart

Achipmunk -

Good advice. I'm not junking anything until I have the truck complete or I can't find someone who can use it. Even then, I may still keep it for my next project... Stovebolt resources are tough to come by in Colorado.

Thanks for the shop manual link Stuart. I was just getting ready to ask if anyone had that because I am tearing down my rear axle and was not sure how to do it.