I'd like to start another thread dedicated to Eaton tech exclusively, mainly due to the fact that even though the Eaton the 14bff share some similar parts, they are two totally different animals, and there isn't a hell of alot to compare. Not to mention the Eaton is way cooler than the 14bff.
To break it down, the only parts interchange between an Eaton and a 14bff would be.....
-Lunchbox lockers for the 14bff will fit in the Eaton.
-The Eaton and 14bff carrier, while different from each other, will accept spider and side gears (and lunchbox style lockers) from either model.
-Disc brake brackets for an SRW 14bff will fit an SRW Eaton IF the Eaton has stud retained drums. Yes folks, some of the HO52's/72's had slide on drums (SRW models only), in my experience it has typically been the older ones. If your Eaton HO52/72 has slide on brake drums, the disc brake conversion brackets from a 14bff WILL NOT WORK! They will bolt up, but the Eatons with slide on drums have a different hub and slightly shorter spindle than the Eatons with stud retained drums. A hub with stud retained drums will fit on a housing that originally had slide on drums, but this WILL NOT solve the problem, as the spindle on the slide on drum Eatons is physically shorter and puts the entire hub/disc assembly too close to the caliper bracket. Believe me on this one, I found out the hard way.
In simple terms, if you want disc brakes on your Eaton HO52/72, you can NOT use an Eaton housing/hubs that originally had slide on drums, you MUST use a housing/hubs with stud retained drums.
For the rest of the disc brake conversion, the game of finding the right studs to use is tricky, as Eatons use smaller 1/2'' studs compared to the 14bff's 9/16'' studs. I drilled out my hubs to use larger 9/16''-18 wheel studs, then used the recommended Dorman stud that is used for a 14bff disc brake conversion. The discs/calipers used are the same, standard chevy 3/4 ton D44/10bolt front rotors and calipers.
And for clarification, stud retained drums means the brake drum is held to the back side of the hub with the wheel studs being pressed through the drum/hub, meaning the only way to service the drum brakes is by removing the axle shaft and hub/drum assembly. Slide on drums means the drum slides onto the front of the hub over the wheel studs before the wheel, and does not require removing the axle shaft or hub to service the drum brakes.
-Axle shafts can be interchanged between the Eaton and 14bff, HOWEVER, the Eaton HO52's/72's have 17 spline shafts/side gears, the 14bff has 30 spline shafts/side gears, but side gears can be swapped between the two. Eatons with slide on drums have shafts that are approximately 1/4'' to 1/2'' shorter per side (per shaft) than Eatons with stud retained drums, but the spline count remains the same.
To my knowledge, this is where the similarities end. Parts interchange is minimal as noted above. I am not sure on all of the bearings, but I know for fact (as per GM Archives) that the Eaton wheel/hub bearings are different than 14bff wheel/hub bearings. The main pinion bearings are obviously very different between the Eaton and 14bff, and there are two different types of pinion bearing used in the Eaton, a ball bearing, and a taper roller bearing, there is no order to when what bearing was used, in my experience they are all mix matched together through their 1947-72 production run. As for the 3rd pinion bearing, that's your typical needle/roller bearing, unsure if they use the same one for the 14bff and Eaton. I am also unsure about any carrier bearing interchange, but I know the Eaton originally used Hyatt barrel type bearings for the carrier. Aftermarket replacements are typically Timken taper roller bearings.
And to clear up any confusion about available ratios, there are 3 common ratios for the Eaton and 1 mythical ratio.
The common factory ratios were:
4.10 (41 tooth ring,10 tooth pinion) (According to the GM Archives, later ones were 4.11, with a 37 tooth ring gear and 9 tooth pinion.)
4.57 (32 tooth ring, 7 tooth pinion)
5.14 (36 tooth ring, 7 tooth pinion)
Then the mythical ratio that no one has yet to find, is a 5.83, which would be a 35 tooth ring gear and a 6 tooth pinion. According to the GM Archives, it was only available in 1963 and only an available option for P30 series vans. It may or may not have actually existed, but the GM Archives says it did. Considering the low performance of engines at the time, and lack of an overdrive transmission, I'm sure this was a very undesirable option, and if any were ever made, I'm sure not many ever ordered in a 1963 P30 van, the only vehicle that it could be had with. This is somewhat of the holy grail of Eaton gear sets though, and I would bet it could fetch a fairly large sum of dough to the right person.
For tons of good info on the Eaton, you have to look past some of the typical BS associated with Pirate4x4, but if you can get around that, there is a wealth of knowledge about Eatons in this thread, page 20+ and beyond/current is where there is A LOT of tech.
http://www.pirate4x4.com/forum/chevy...aton-h072.html