Differential specs

[Fiddy B2C]

Can anyone tell me where I could find the specs on the differential for a 1950 B2C?  I know it has a 4.11 ratio, but not sure of the spline count, R&P size or any other specs.  

[Don Coatney]

You can find this information in a service manual. They can be found on E bay.

[Fiddy B2C]

Thanks Don, I have a service manual, but it doesn't show the size of the gears, just the number of teeth per respective gear.  I'm trying to figure out if this is an 8.75 rear end?  I'd like to put 3.73 gears in it, but not sure where to look for them.

[Young Ed]

2 minutes ago, Fiddy B2C said:

Thanks Don, I have a service manual, but it doesn't show the size of the gears, just the number of teeth per respective gear.  I'm trying to figure out if this is an 8.75 rear end?  I'd like to put 3.73 gears in it, but not sure where to look for them.

They might be that size but don't think you can just buy modern gear sets and install them. You need vintage parts either NOS or used take outs.

[Plymouthy Adams]

if it is stock it will not be the 8 3/4 as you are thinking though it looks like it a bit being a banjo style axle. the 8 3/4 did not come out till later and are easy to recognize by the casting numbers on the drivers side of the hog head.  being a truck you have basically two different carriers available...a two spider gear or a 4 spider gear unit....per my interchange book information this make a difference in what gear set will mount to what carrier...and is reference by the suffix A and B there is a difference in the undercut of the ring gear I have been told...

 

the two spider gear is the same hog head as found in passenger cars of the era and light weight pickup trucks..

[Fiddy B2C]

14 hours ago, Plymouthy Adams said:

if it is stock it will not be the 8 3/4 as you are thinking though it looks like it a bit being a banjo style axle. the 8 3/4 did not come out till later and are easy to recognize by the casting numbers on the drivers side of the hog head.  being a truck you have basically two different carriers available...a two spider gear or a 4 spider gear unit....per my interchange book information this make a difference in what gear set will mount to what carrier...and is reference by the suffix A and B there is a difference in the undercut of the ring gear I have been told...

 

the two spider gear is the same hog head as found in passenger cars of the era and light weight pickup trucks..

So, if I can find a 48-53 Mopar with the right ratio, I can just swap out the hogs head?

[DJ194950]

Mostly yes on the 48-53, but if you would like to be absolutely surebefore a purchase , post what you find as per make model  car as to your possible source and one of us here can look at the exact specs in a interchange manual for you-no problemo! 

DJ

[Brent B3B]

19 hours ago, Fiddy B2C said:

So, if I can find a 48-53 Mopar with the right ratio, I can just swap out the hogs head?

Check the "spline" count on the axle shaft..... 

[P15-D24]

C models have a different spline count than B and passenger car models. If you swap the pumpkin to a 1/2 ton or pass. car you have to do the axles also. 

[Brent B3B]

Didn't know that...... never mind 

[Plymouthy Adams]

5 hours ago, P15-D24 said:

C models have a different spline count than B and passenger car models. If you swap the pumpkin to a 1/2 ton or pass. car you have to do the axles also. 

would you not just be able to swap the side gears?  I know there are variations in the trucks from passenger but that the smaller panty-weight trucks are same as passenger cars...and that some are carrier difference between those having 2 and some having 4 spider thus the different carrier number and gear set to match the backcut of the carrier..

Edited October 7, 2016 by Plymouthy Adams

[Desotodav]

1 hour ago, Plymouthy Adams said:

would you not just be able to swap the side gears?  I know there are variations in the trucks from passenger but that the smaller panty-weight trucks are same as passenger cars...and that some are carrier difference between those having 2 and some having 4 spider thus the different carrier number and gear set to match the backcut of the carrier..

I had the side gears swapped out when I went from the 4.1 to the 3.54 diff in my truck. I found that the car axles were an inch or so shorter than the truck axles, so changing over the pumpkin and the side gears from the car and using the truck axles really was the only way to go for me.

[59bisquik]

On my 55 C1B, it came with stock 4.11's. I used the differential from a 54 Plymouth with 3.73's. It bolted into the truck housing, using the truck axle shafts. The car and truck spline count was the same, but the car axle shafts are about an inch shorter. The only change I had to do to the car diff was change the yoke to the truck style.