Need Help with T50 Eaton Rear End ID

[sweepleader]

I have a 1969 T50 chassis under a firetruck that has an Eaton single speed rear end. GVW rating is 19,500. I am trying to ID the rear end for model number or any other information that would help with replacing the diff.

The glove box sticker lists the rear axle as "Option H21BA, H170, 6.17 ratio".

Crawling under the truck I found the following:
Bottom front of the pumpkin "3826111GM", (likely a casting number) with "D2" below and "276" at 90 degrees to the long number.
Top left side of pumpkin, stamped in "JV1167C2"
Top of pumpkin flange, between 2 bolts, "X"
13 Bolts

On the outboard axle shaft face, "T75" and "S13", each repeated twice, 90 degrees apart. Nothing along the edge of the axle flange.

Anyone know what any of these mean?

Thanks in advance.

[Robert1970C20rstbukt]

H170 is the axle model number, it's actually made by Rockwell Meritor. 3826111 is the GM part number for the carrier itself, that's all I can figure out.

[sweepleader]

Thanks, I will keep looking on that basis. I think the service manual shows Eaton, guess that might just be the pictures. I will recheck. Thanks again.

[sweepleader]

Pinion by [url=https://www.flickr.com/photos/154604744@N08/][/IMG]

KIMG0041 by [url=https://www.flickr.com/photos/154604744@N08/][/IMG]

Thanks much for the suggestion but I searched for Rockwell H170 and got a totally different unit. 8 bolts on the pinion bearing retainer vs 5 on mine and a different look to the casting.

I have spoken to a couple of people who think it is a GM corporate axle, I guess I gotta find a pro in the business and get him under the truck.

Thanks again.

[Robert1970C20rstbukt]

You're welcome, glad to help. I didn't check the GM part number until now, but a Google search says that carrier is for an H150 axle and I found a few pictures that show the pinion retainer with five bolts. The original axle must have been replaced at some point.

[sweepleader]

Yup, I am convinced you are right on with the exception that I doubt the diff has been changed. It still has the same red paint as the rest of the chassis, applied by the maker of the fire body. The truck only had 4600 miles on it when I bought it, less than 6000 now. The build sticker says H170 and googling that with Chevrolet brings pretty much the same thing you found. I also found that it was made in a two speed version that has even deeper gears! So this looks like a dead end, at least as far as my hopes to reduce the ratio. I do appreciate your efforts, thanks again.