1940 Buick rear end

I recently purchased a 40 Buick Super that needs a rear end from lack of fluid. I hear that 40-54 ring and pinion are the same but I don't know how to set up the gears properly. I would like to find a complete rear end but if I cant I was wondering about just changing the center chuck and I don't know if the inner driveshaft is part of the pinion gear or does it separate? Would I have to include the driveshaft with it? Also what year and series would interchange?
 
I recently purchased a 40 Buick Super that needs a rear end from lack of fluid. I hear that 40-54 ring and pinion are the same but I don't know how to set up the gears properly. I would like to find a complete rear end but if I cant I was wondering about just changing the center chuck and I don't know if the inner driveshaft is part of the pinion gear or does it separate? Would I have to include the driveshaft with it? Also what year and series would interchange?

1940 through 1955 interchange. Yes, just change the entire center "center chunk" or "pumpkin" . In other words, the whole gear set. I did this on my 1950 with one from a 1955. The inner drive shaft does seperate, but would not need to if the length is the same.

Ben
 
Is there a u joint or is it a spline type between the inner shaft and the pumpkin? Would I be able to separate it by jacking the housing back a little or would I have to remove the whole rear end? Better yet, would you know what years have the same length driveshaft?
Bill
 
Bill, they are splined and pinned. Can be difficult. I did it , so you can I am sure. Rear end has to be removed. I do not know the answer to the last question.

Ben
 
A little bit of trivia, I have built the running gear for a '52 RM convertible. I could see the install and removal of the drive shaft was going to be a challenge. I had a 4 dr. trashed parts car in my inventory. For what ever reason, I opened up the drive shaft tube and found that shortly before its demise, someone had replaced the drive shaft with an aftermarket one that did not require special tools to install! I thought I would have to shorten the shaft for the convertible from the 4 door, but it was even the correct length! You just never know where you will find what you need:)
 
A little bit of trivia, I have built the running gear for a '52 RM convertible. I could see the install and removal of the drive shaft was going to be a challenge. I had a 4 dr. trashed parts car in my inventory. For what ever reason, I opened up the drive shaft tube and found that shortly before its demise, someone had replaced the drive shaft with an aftermarket one that did not require special tools to install! I thought I would have to shorten the shaft for the convertible from the 4 door, but it was even the correct length! You just never know where you will find what you need:)

Installed how, Bob?

Ben
 
Installed how, Bob?

Ben
It was probably close to 25 years ago I did this, so my memory won't be perfect, but I think the slider that went over the pinion was simply a lighter slip fit than the OE Buick, so installed without special tools by any service provider. I remember at the time researching to proper tooling to do the install, and before the internet, these things were more difficult!
 
I recently purchased a 40 Buick Super that needs a rear end from lack of fluid. I hear that 40-54 ring and pinion are the same but I don't know how to set up the gears properly. I would like to find a complete rear end but if I cant I was wondering about just changing the center chuck and I don't know if the inner driveshaft is part of the pinion gear or does it separate? Would I have to include the driveshaft with it? Also what year and series would interchange?
I have owned a 1940 Super for over 50 years. About 20-25 years ago I bought a Century 3.90:1 center section. The unit I removed has been in my
shed ever since. It never gave me any trouble and I recall having it adjusted by a friend of my dad's when I put in a clutch. The car probably had between 50-60K when I pulled the rear. You can have it for the cost of freight, I have kept it all these years because I didn't want to junk it and
would like to see it in a new home. I agree the shaft is hard to remove but I was able to do it.
 
I have owned a 1940 Super for over 50 years. About 20-25 years ago I bought a Century 3.90:1 center section. The unit I removed has been in my
shed ever since. It never gave me any trouble and I recall having it adjusted by a friend of my dad's when I put in a clutch. The car probably had between 50-60K when I pulled the rear. You can have it for the cost of freight, I have kept it all these years because I didn't want to junk it and
would like to see it in a new home. I agree the shaft is hard to remove but I was able to do it.
 
The disassembly/reassembly steps are shown in the 1940 Shop Manual (copy attached). There's a couple of exploded parts views included as well.

It will take 2 messages to send the pages. Hope this helps😊.
 

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I recently purchased a 40 Buick Super that needs a rear end from lack of fluid. I hear that 40-54 ring and pinion are the same but I don't know how to set up the gears properly. I would like to find a complete rear end but if I cant I was wondering about just changing the center chuck and I don't know if the inner driveshaft is part of the pinion gear or does it separate? Would I have to include the driveshaft with it? Also what year and series would interchange?
 
I have a 1949 super 50s series rear end up for sale now on site in classifides came out of a running driving car.alot of extra parts also 150 for everything
 
When I went to examine the gears I have I was surprised to see the mechanic had disassembled it. I assumed he had just swapped center sections.
It was in a black plastic trash bag in a box and I had not looked at in in years. The gears appear fine as do the other parts. I have what appears to be a nos bearing with it. coolcar348 does not want to try to assemble it, so the offer still stands, and it appears to me just shipping the internals without the housing would be a lot cheaper.
Email your phone number to tjbian64:)gmail.com
 
When I went to examine the gears I have I was surprised to see the mechanic had disassembled it. I assumed he had just swapped center sections.
It was in a black plastic trash bag in a box and I had not looked at in in years. The gears appear fine as do the other parts. I have what appears to be a nos bearing with it. coolcar348 does not want to try to assemble it, so the offer still stands, and it appears to me just shipping the internals without the housing would be a lot cheaper.
Email your phone number to tjbian64:)gmail.com
 
I am not interested in buying, I want to give one away. It has been in my shed 20 years and I think it is too good to scrap.
 
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