The Stovebolt Site Forums The Parking Lot Big Bolts 68 c50 rear end

Does anybody know how I can find out what rear end I have under my 68 C50. I can't find a tag on it.

Hy pipeliner78, could you tell us what the g.v.w. of the truck is, and is it a single speed or two speed rear axle?

The g.v.w. is 19,500, and it is a two speed rear end.

It's a 15,000 Lb. axle.

Hy pipeliner78, if it's an electric shift it's an Eaton model 16121 or 16221, if it's a vacuum shift unit I'll have to do more looking, hope that helps.

If it's a vacuum shift it will more than likely be a Corporate GM rear rated at 15.000 pounds.

Mike B

It is a vacuum shift. I'm needing brake parts for it and the guy at napa said if i knew what kind it was he could look up parts for it. Or if any body knows part numbers for the brake parts. I need every thing. Years ago the cylinders froze up and we cut the adjusters, and took everything out. Of course it has been mis placed. Any help is appreciated.

Hy pipeliner78, if you know the diameter and width of your brake shoes your parts man should be able to figure out what you need.

Ok I think they're 14 X 6 would that be right?

Hy pipeliner78, all the rear brake diameters in my brake book are 15", there are two different widths mentioned 4" and 6". The wheel cylinders listed for the six inch wide shoes are a 1 5/8" bore. Do you have anything left to compare to?

I did find two of the brake shoes but i'm not sure how to measure them.

i just went and measured the width is 5 inches.

Hy Pipeliner78, Unfotunately the middle to late 60s are a time of change for truck braking systems. Is your master cylinder a single or dual system type? The rear brake shoes appear to be the same from 1966 - 1970 on the 15000 - 28000lb. two speed axles o.e.m. p/n 3912439. Your rear brake system could be General Motors automatic adjusting type, Wagner manual adjusting type, or Wagner automatic adjusting type, I'll try and narrow it down a bit more. Any chance of posting a picture of what you have left?

It is a single master cylinder. It has two wheel cylinders for each side. and it has automatic adjusters, kind of like on a smaller truck. I haven't pulled anything off yet, so i don't have a picture. Thanks alot for all your help so far!!!

Sorry I'm not more help describing my own truck.

It also has an arm attached to each shoe like on a smaller truck. The one that touches the adjuster.

Hy pipeliner78, I've done some more research, and I think what you have is the General Motors rear brake setup. Parts I have found are
upper rear wheel cylinder o.e.m. 5464135, Raybestos p/n WC37159, $29.79 at Rock Auto
lower rear wheel cylinder o.e.m. 5464136, Raybestos p/n WC37160. $29.79 at Rock Auto
rear brake shoes Raybestos p/n 442PG $204.89 at Rock Auto, hope that helps, if you need more parts, just list what you need.

Well getting ready to swap 7:17 ring & pin gear and hopeing all goes smooth any Eye Opening suggestions. worried about getting pin bolt off heard it was torque
300 pounds I just want to pull it and change the pin gear get the bearing taken off and pressed on new pin gear then change the ring gear..... hope all goes smooth

Thanks alot 3B. One more question. Do you have the number for the wheel seal?

Hy pipeliner78, I beleve the o.e.m. pn for the inner hub seal is 3874368 that is equal to National 9128S, Rock Auto has one at $7.42, so the second one would be a different price, hope that helps.

Thanks alot, you've been a huge help.

Hy pipeliner78, you asked about adjusters in a PM, are you asking about the entire adjuster setup or just the adjuster screws?

I need the entire set up I've lost the parts we took after one of the cylinders froze up.

Hy pipeliner78, okay these parts are all made by Euclid, and I couldn't price them because Rock Auto doesn't seem to carry Euclid
return spring set [enough for the whole axle] p/n E-4023 replaces o.e.m.341520
hold down kit [enough for one wheel, may include return springs for one wheel] p/n E-4121
automatic adjuster kit RH [enough for one wheel] p/n E-4122 RH
automatic adjuster kit LH [enough for one wheel} p/n E-4123 LH
hope that helps.

Does it have 2 adjusters on each wheel or just one, the backing plate looks like it might be 2?

Hy pipeliner78, according to my drawing, each shoe has its own adjuster, hope that helps.

That's what I thought, thanks.