10/22/2017
A little tech tips from a fellow naxja member ken stein
A few notes on Dana/Spicer diff setup.
First - the carrier bearing caps are machined flat on the backs and drilled for bolts, then bolted into the case before they are line bored. What this means is that they MUST be put back in the housing in the same positions and orientations as they left the factory or your carrier bearings will likely be destroyed. They might not even turn. Also if you lose them, you can't just swap junkyard ones from another axle housing in. Most people know these things, but some don't.
Next... A lot of people don't realize this, and recommend using a hammer and a punch to mark the caps for position and orientation. However, every single Dana Spicer axle I've ever worked on comes premarked! They use a random letter stamp. As pictured, you will see a letter stamped into the cover mounting fl**ge near one end of each bearing cap. It will be vertical on one side and horizontal on the other. Or in this case upside down on one side. They used the letter K on this axle. The letter is stamped into the carrier bearing cap as well, so you just match the orientation up and you're done.
This is great because it means if you are buying a used axle and you want to check how skilled the previous mechanics were, you can pull the cover and know at a glance if they got it right. And also if they lost the caps and put junkyard ones on, you have a 103 out of 104 chance of catching them because the orientation and letter used likely won't match unless they know this and spend a lot of time pulling diff covers to get matching ones.
If you see different letters on the case and caps, or the orientation is wrong, walk away or offer a price that you are happy with knowing you will need to put the caps back (or replace them if they are wrong), have it line bored, then replace all the carrier bearings and possibly redo the carrier bearing shims.
Always check if the stamping has been done before pulling the caps. I've never seen a Dana Spicer axle that wasn't stamped, but if you find one, stamp it yourself first...