Hot Rods GM Pumpkin Identification

Just got this 41 ford coupe project that someone else started, but he passed before finishing it. After trailering it home, I find out why the rear end was frozen; Someone drove it with no oil in the differential and it is fried. Now, the problem is, what is it? The pumpkin mounting flange is 11.5 inches in diameter, and 8 inches from the mounting flange surface to the opposite side casting where the pinion shaft comes out. Ten bolts hold it to the axle housing. The ring gear has the numbers 41 12 GM 357 HHA stamped into it, and it is 8.5 inches O.D. at the mounting surface side. The axles are 29 splines. The pumpkin casting has numbers cast into it; 0207 and 622496. I've been told it is probably Olds or Pontiac, possibly 1957. Can anyone confirm this? I need to find a new carrier and ring/pinion set. HELP!

 

while some guys could identify it by that, most....like me...can only do it visually

any pictures?

 

Yes yes a pic is better than your Than your 150 words here also.

 

One pic is worth a thousand words.

 

So, you've had 2 minutes since the last post. Where are the pictures?

Frank

 

does it look like this?

 

ON ebay, there is a vender Fabcraft is there moniker. The sell everything including gearsets, bearings and complete rebuild kits. I have found them to be very reputable and think they will have the parts and answers you need.
Good Luck!

 

Yes, Brad at Fabcraft can help you. He has gear sets and parts.


That is a Dana differential like used in full size Olds and Pontiacs from about '58-64. You can buy bearings and seals at Napa. I'm currently rebuilding one.

That has the posi tag on it! Yours is a Also, it's a very stout unit with a 9 1/4" o.d ring gear. 41:12 is your gear ratio - 3.42:1. Not sure why it says 357. Count them. I've got a set that was stamped wrong.

 

Yes, that looks like it. Thanks for taking the time to post picture. Now, what is it? Tnx, Russie.

 

Thanks, I'll check it out. I appreciate the tip. Cheers, Russie.

 

Okay, finally figured out how to upload pictures. There are three here. Cheers, Russie.

 

Jim, Looks like I responded to the wrong message, so this one is to you. Yes, your picture looks like my pumpkin and the axle housing is similar except mine does not have all the brackets around the pumpkin area or the shock mounts like yours. However, the pumpkin looks nearly identical. Nice restoration on yours, I like the color. Cheers, Russie.

 

1) Why did olds/pontiac use/get the good rear? What was chevy using at this time?


2) Just tell me everything you know about the olds/pontiac rear.

 

Someone else will have to tell you the answer to that. I don't know. I also think Buick might have used these in some models.

 

Chevy cars used a rear that was ok with the mild 265 engines it was designed for. Kind of weak for the later more powerful engines.

Olds Pontiac had bigger engines, more power, heavier cars, so they used a beefier rearend.