The Stovebolt Site Forums The Shop Area Driveline 1946 differential side gears

We have a 1946 Chevy 1/2 ton and need new differential side gears due to wear. Does someone have the part number or know where I can get 2 side gears? The drive axles are good. Thank you for the help.

Rear ends are so plentiful, most just find a modern one that fits, get better ratio while at it.

Ed

You will be looking for, 46 - 49 ALL 1/2 TON COMM ( 16 teeth ) #3652344

My parts book is the 1929 - 1949 so gears may be available in later assemblies as well. The gears are in section 5.528 of the parts manuals.

Thank you Joe we are at Frog follies in Evansville and looking. Do you know I'd 3/4 and ton are the same?

Mine (we assume is the original) currently has 16 teeth on the outside, but this one from "The Filling Station", that includes 1946, has 18 teeth. We can't find any with 16 teeth online and, since the rest of the differential is already rebuilt, it's not practical for us to scrap it and start over.

Can anyone advise as to what will jive with what year/teeth/tonnage of truck?

It might be possible to change both the side gears and the spider gears in your differential. The 18 tooth side gears may match with the later spider gears, and as long as the space inside the differential case is the same (between earlier and later), and the spider gear shaft is the same diameter, then it should work.

Looking at the parts manual, it appears that the 18 tooth side gears that The Filling Station has are for 3/4 and 1 ton differentials.
1/2 ton side gears with 16 teeth appear to be the same from 46-54, so you might be able to source a set from a rear axle that someone is getting rid of.

Post a couple pictures of your worn gears, they may not be as bad as you think.

Re Joe H: The full size pictures are a couple of replies above yours (^). I zoomed in on the inside of them here - that's where the concern was.

Our mechanic friend ("Hog Wild" is my husband) thought that we should replace the side gears since the insides were so worn. The matching splines on both shafts are (somehow) still in really good shape, but the inside of these gears is really warn. Our friend said they may last a few years or they may last 25 years but we may as well try to replace them while we have it completely torn apart.

What looks like wear, the tops of each tooth being shorter, may not be what it looks like. If the teeth wear, it will be on the sides, the tops of each tooth will be pointed. The axle shouldn't even touch the points. Slip an axle on to the gear and have a good look. This is what a worn spline will look like.

re count the splines .............

Dusty I count 17 splines

Yes , I counted 17 splines in your picture as well . So the 16 and 18 spline options will not be valid . I looked in my spares bin and the 17 spline gears are from '56-'59 Task force trucks (1/2 ton)


What diff do you have ?

My GM parts book shows 1946-62 (except posi) as using the same ones.

The 16 vs 18 was for gear teeth, not splines.

@ Dusty - is a THANK YOU! We had exhausted all of our resources, and still couldn't figure out why we couldn't find the right gears anywhere. This makes complete sense! I've attached a few pictures of the differential, and the 3.55:1 ring and pinion we're going with.