4X4HIGH said:
Couple years ago there wasn't anything available for gear for an Eaton, maybe things have changed in the last few years but i'd rather install an axle that is widely available and still being used in trucks today. Wasn't the last Eaton rear axle made about 30+ years ago?
you can get 3.90, 4.11, and 4.57 gears (new) for the Eaton. they are very pricy though. most of them came from the factory with 4.57, and the 5.14 isnt uncommon either. you can't get the detroit for it anymore unless its used or NOS, but the 14 bolt locker and shaft trick does work. you can buy every bearing and seal you need to rebuild the chunk over the counter of any parts store. wheel bearings are easy too. the brakes, though, good luck if your drums are shot.
what i would look for...at some point around '67/'68, the center section casting was changed to add an extra oiling passage to the pinion bearings. you may find them on older axles, and not on newer ones. i havent been able to pin this down for sure. its noticeable if you look at the pinion end, there will be an extra lump on one side. i can try to dig up pics (i have one of each).
also, some of the axles have a load bolt on the side of the centersection, like the Hi9. it helps prevent the pinion gear from "walking" under load. this may be a one ton vs. 3/4 item, but again i am not exactly sure. you just have to look.
finally, both of the centersections i have have the gear ratio stamped into them. not the actual number, but the # of pinion teeth over the # of ring gear teeth. one is a '65 that was originally from PA, the other is a '68 originally from MN, so I have to believe this is a factory thing.
srw versions are 65" wms, drw are 63" wms (same hub types as 14 bolt). there is a van width, that has a wider housing and wider shafts, but these are rare (at least around here). i would guess the shafts would be harder to find, too. i think this is somewhere in the 70" neighborhood.
speaking of shafts, they are pretty hefty. using a tape measure, mine look to be about 1.5" where they neck down, and around 1.7" at the ends.
you can get new yokes for these if you want bigger u joints. i know jess @ high angle can get them, and if you have spare time and a spicer book you could probably scare some up. also, have you ever seen the pinion gear for one of these? slightly over 2" in diameter, HUGE.
a guy on pirate made a custom diff cover for one out of a sch 40 pipe cap, it was pretty sweet, and tough as hell.
oh, and the ring gear is actually 10-1/8", not 10.5". the petersens 4wor article that says they are 12-1/4" is mistaken, that is the larger brother called the H110 that was optional under one tons and usually under C40 and their ilk. it has 10 lug nuts, and one ton trucks with it optioned had 5 up front, like the 3500HD trucks of the 90's.
phew, i think thats about it. sorry for the novel.
