I want to change the gears in my rear axle and plan on getting a used axle and swapping it out but am not sure how to identify which axle is which.

The 3.55 rear axle uses to different sets of tags:

S862A, S862B and S862C or,

S869A, S869B and S869C.

Which one is which? And, what do these designators mean?

I know these are for the 8.8" rear end but I want the best possible unit for towing. any help would be appreciated.

 

Why don't you just swap the ring and pinion. It seems to me that would be much less complex.

Besides, it may even be cheaper.

 

I thought about that but decided that it would cost more since I wanted to go with limited slip. By the time I bought the ring and pinion gears, the differential, and the bearings I was at $650 (from Reider Racing). Then I either have to install it or pay someone to do it.

I can get a low milage axle from a salvage yard with a 3.55LS for about $700 and installing that doesn't reqiure all the measurements and set up that changing the gears do.

I'm pretty mechanically inclined but I don't have the measurement equipment to install new gears and am not too sure if I can do this myself.

 

Now that's a different ball of wax. I aggree and axle swap would be better provided you can find one at a recking yard that is low milage and in good shape. I don't know what to tell you about the codes. I remember seeing and L in the number on my mustang which is limited slip. Trac-loc I think.

If I remember - 3.L27 or something like that. Its too cold out and the car is too low to the ground to look right now.

My truck is different, so I will look later when the ice melts if you haven't found out.

 

Crawling under a truck with all this snow and ice! I did it because, well, ...I want a new rear end!

The reason I need to know is the junk yards use the codes on the tags that are on the axle (which I listed on my first post) It seems stupid that they dont use the same codes that Ford does on the vehicle information sticker.

I think I found one at a local yard but their computer was down from all the damaged wires from the ice storm.

Thanks for looking if you get to it.

Jeff

 

sorry Jeff -
Mine says S836J
3 08 88 5801

I have 3.08 open diff 8.8
I guess it won't help.

I'll ask around.