Another ‘65 C20 14-bolt conversion

[azdeltawye]

The old OE 4.57 HO52 Eaton rear end in the truck had been howling and leaking for quite some time. So I finally decided to do something about it. Also I also wanted to change out the gears to a more gas friendly 4.10 ratio. After a bit of research I determined that I could find a complete 14-bolt corporate GM 10.5” full floating (FF) rear axle with the gears I wanted for much less than getting a ‘new’ used third member with 4.10 gears for the Eaton. I decided on the upgrade. I found a low mileage donor FF axle from a 2000 C3500 single rear wheel (SRW) with a 10.5” ring gear and 4.10 ratio for $275 at a local junkyard.



Initial inspection of 14-bolt FF 10.5” axle; start the disassembly and cleaning process


One of the great features of the newer 14-bolt rear end is the removable brake drums (without having to remove the axle shaft and hub).

Apparently somewhere around 1998 GM stopped producing this axle and it is now made by American Axle Manufacturing (AAM). Additionally the model year 2000 was also the last year of rear drum brakes, 2001 and later went to disc. Contrary to the 14-bolt bible on billavista.com (the definitive source of information on these axles) the distance between wheel mounting surface (wms) to wms on this particular axle was 65-5/8” instead of the ‘standard’ 67” for the SRW. This was a bit of a disappointment since I wanted to match the track width of the front axle which is 67-5/16” (’65 control arms with ’71 spindles).