I have a 2012 2wd RCSB STX 5.0 with 3.31 gears and I am looking into adding the OEM differential part number CL3Z-4026-A (electronic locking)into my fTC05A 3C31-9.75 (non-LSD 3.31) housing that came factory on my truck. When I initially went to buy my truck I searched the entire nation for a truck equipped with the locker, and I couldn't find one in the color I wanted. I did however find a Blue 2wd STX RCSB that did have one so I do know it was an option. Either way, I will also be installing the factory switch that is located where the 4wd switch or coin holder(2wd models) is. I won't however be running it through the factory computer. I will be ordering this part in the next couple of months and then come back to this thread and do a step by step. If anyone else has tried this PLEASE chime in.

 

Are you planning on swapping gear sets while you have it apart ? I'd take it up to 3.73's or 4.11's.

 

I would love to run some 4.10's but the gas milage would take a dive. I drive A LOT! I have put 9000 miles on the truck since OCT 25th...

 

what switch needs to be mounted and how much does the locker cost

 

I couldn't find an exact picture online but it is similar in style to this switch, but you click it one position clockwise and it locks the read end. No pulling it out to lock, and obviously it doesn't have the 4wd option. I am almost positive the tremor has this switch standard. The differential part that I have listed above sells for just under $400 and is the section that the ring gear bolts too.

 

I'm really anxious to see how this goes. We have talked about this on our 2wd shop truck.

 

Just be sure to find a good shop. It's not a simple job for the typical home mechanic.

 

I'm interested in this mod as well - whether you do yourself or have a shop do it for you. Would be great if you could let us know what it cost (parts & labor) as well as functionality once installed. I have the same 3.31 gears so let us know if you keep the gears you have or change those out?

Thanks & good luck!

 

Subd on this. Interesting idea.

 

Why not just go with one of the selectable aftermarket ones?

In the long run they probably would be cheaper.