The Stovebolt Site Forums The Parking Lot Big Bolts 2 Speed Rear End Question

Hi.

Will a 1958 (2 ton ????) vacuum 2 speed pumpkin with 6 lug Budd wheels fit a 1948 2 ton 2 speed rear end housing.

Thanks, Paul.

Won't work. Different Differential housing, axles, & pumpkin.

Thanks spanky. Do you know what year things changed?

'46-'53, are exactly the same. 1954 went to larger axle shafts.

I might ad, that '46-'48, had the bolt flange axle shafts,& '49-'54 had the splined flange axle shafts.

Thanks spanky for the info. I had wondered about the flanged axles too. I have a rear end out of what is suppose to be a '48 with the flanged axles and my driver '48 has the splined axles. Doesn't matter too much either way I guess. I'll just tell everyone my '48 has a "modern" rear end upgrade.

Thanks again, Paul.

I have a 48 with the splined flanged axle shafts, I am reasonably sure the axle is original to the truck.

Grigg

I guess anythings possible Grigg. I've owned 2 '48's, & sold parts to 3, or 4 guys with '48's, & all I've came in contact with had the bolted flange axle shafts. If you look in the Chevrolet Truck Parts Catalog, it will even go as far as listing a part no., for a '46-'51, splined hub axle, but i've never seen a '46, or '47 1st series, nor the '47, & '48 Advance Design 2 tons with anything but a bolted flange axle. The '46, I just sold, had bolted flange axles. Not to say there's not any out there. I just haven't seen one.

I've done the brakes on both of my '48's, they both had the splined axle shafts. Although, both of mine are single speed 4400's. Are we talking about the 2 speeds only?
Scott

Called a buddy of mine last night that has a collection of Big Bolts. He has 3 '47-'48's with 2 spd. rear axles. He said two of his had the bolted flange axles, & one, had the splined axle. So, looks to be both ways, as an option. Could be a some had Timken 2 spd.'s, & some had Eaton 2 spd.'s. I know, the two, are almost identical. Could also depend, where the truck was built. Most all these trucks in my area, were built in Baltimore, a few in Atlanta.

It was my understanding that the Timken axle is somewhat less common, and the axle shafts in it are a coarser spline on the inside ends, not sure if this makes any difference here?

I think my theoretically 48 two speed axle is the Eaton version, with splined ends.

Did the Timken version have splined big ends, or bolt on?

Grigg

O.K., this 1947 Chevrolet Service Bulletin, explains it all. According to this bulletin, Dated December 1947, any 1948 Chevrolet 1 1/2, or 2 ton truck, built after Dec. 1947, would have the new splined hub, & axle flange, & any Chevrolet truck built before Dec. 1947, will have the older bolted flange axles. http://chevy.tocmp.com/bulletins/47csn1201.htm

Grigg, the 2 spd. axles, I have in my Chevrolet 2 tons, are the Timken 2 spd. axles. I've mostly seen the Eaton 1350 2 spd., in GMC's. Only difference, i've run into on the splined flange axles, before the bigger 1954 version, is in 1952, the design of the differential side gears changed, to where the end of the older axles were 16 splines, & the newer 1952 versions were 27 splines. I just sent a set of 27 spline axles to a guy in Illinois, who has a 1953 6400 series Dump truck. That's one thing, I have plenty of, is axles.

Thanks for the info spanky. I'll keep in mind that you have lots of axles. A side note to the splined hubs. On my drivers side there is a little play between the axle and hub. Not enough to hurt anything, but it suppose to be tight. If it gets worse wouldn't I have to replace the hub and axle?

That's good info, now we know how to quickly spot an early 48 or a late 48 big truck

Grigg