The Stovebolt Site Forums The Shop Area Engine Shop 14-Bolt Rear Axle

Just thought I'd share where I am right now with my rear axle conversion. My 55.1 stock rear end had gear problems and rather than rebuild, I decided to swap to something a little stronger and newer. After some good feedback from this forum, I decided on the chev 14-bolt (9.5" ring gear) axle because of availability. The following is some info:

1. Drum flange to drum flange is 64" vs the stock 62"
2. The spring saddles have been removed from the top of the axle and will be relocated to the underside.
3. I will likely relocate and re-use the 14-bolt lower shock mount brackets.
4. The 14-bolt uses a 1350 u-joint. I am looking at using a conversion u-joint (1310 to 1350) but I may have to get a new driveshaft fabbed because the current driveshaft may be too long now.
5. I plan to use my Eagle rims (6-lug 15x8's with 2 1/2" backspacing)with 245 or 25570R15 radial TA's. I hope I don't have rear fender clearance problem (I may have to modify/extend the fenders).
6. The 14-bolt sure is a lot heavier than the stock 10-bolt! The drums are impressive too.

I would appreciate hearing from anyone who has already done this conversion. I think it is all going to work OK but it is good to hear others' experience.

I did that swap on my dads 71 3/4 ton 4x4
only i also swaped the front dana 44 for a dana 60. every thing bolted tight in
the sping perches were lined up perfect from the old stock rear end
all I had to do was shorten the drive line a littel and put littel wedges under to get the right angle for the rear drive line

Tony's done that conversion under a few 3/4 ton AD's. I thought about it, but have opted for the round 12 or 10 bolt, I just don't like the odd shape under my 52. Since you have 6 bolt hubs, I assume you got a semi-floater out of a van? They are a bit wider than the pickup rears.

The truck wrecking yard nearby did not have any 12-bolts and he has a lot of trucks in his yard. My 14-bolt rear axle came out of a 3/4 ton pickup I think. The ring gear is stamped with "4 89" which I assume means the gear was made in April 1989. No guarantee that the truck is an '89 though. I still need to find out exactly what truck this axle was pulled out of so that I can easily order stuff like brake shoes... you know how those parts counter guys are if you don't have the exact make and model. It is indeed a semi floating axle. Anyone familiar with those "conversion" u-joints? One of the websites I visited mentioned that it was NAPA part #447 but when I searched the NAPA website for that part, it sure wasn't a u-joint. A driveshaft place in San Antonio sells them for about $23. I may just fork over the $300 to have a complete 1350 u-joint style driveshaft fabricated and then I should never have to worry about anything past the transmission.

The junkyard you bought it from should be able to tell you exactly what truck the rear was made for. For getting brake parts, find a mom & pop parts store, one that's been there forever. If you go in with a pair of shoes, they should be able to tell you what they are, just by looking. If they have to, they can measure and look it up in the books. Same for wheel cylinders. They should also be able to help you with an adapter u-joint. For actual I.D. on the differential, try going to the library and looking in the shop manuals, some of them will tell you what to look for and what the codes mean.