Posi lock: Questions!

I’ve got a 2015 SR5, 4x4 without Posi on the rear end it’s a 3.73. I’m wanting to have that option, so do I have to change out the complete rear axle, or can I just get the rear differential from a off-road with 3.73 with e-locker, and put it in my current rear end housing, I’ve done this stuff to other rigs, but never a Tacoma! Thanks for input!!

 

The rear axle housing for a factory elocker is a different shape than the housing for a non-locker. If you want to keep the same axle housing, best bet would to install a locker of your choice on you existing 3rd member or buy an assembled 3rd member for your truck from a place like East Coast Gear Supply and send in your existing 3rd member as a core.

EDIT: Below is a picture of a factory elocker rear axle housing....notice 'rectangular' cut out to the right side of opening....housing from trucks with without factory elockers don't have this cut out and just have a round opening for the 3rd member (ie no rectangle cutout)

 

While you may not have a mechanical LSD, your truck should have traction control (TRAC or A-TRAC can't remember for SR5) which will selectively use the rear brakes to get you out of a bind when it detects a wheel spinning while the other is stuck.

 

I’ve got OEM 4.10’s front and rear available if you’re interested in regearing.

early Sports had mech LSD
Only 4cyl came with 4.10 option. Rest was 3.73.

OR is weaker 8” elocker. Others are 8.4. Generally 3.73.

people have retrofitted elocker.
Or otherwise you’re looking at aftermarket elocker, air locker, or better LSD type diffs such as TrueTrac. Check what’s available including ECGS.

there’s many places that can do the work whether on truck or bench. It may require doing other things while you’re in there.

my plan is 4.88, truetrac rear, 8.4, and see if I can find anything similar for the front. Their is stuff out there just not always in stock.

don’t really want an elocker that isn’t instant on, or air locker to also needs compressor and whatnot.

I think I’ll be fine with the others. Time will tell. Anything is better than nothing.

ECGS seems pretty competitive
Revolution Gear and Axle is a good parts source as well.
Check out ZUK gearinstalls website.

I don’t believe OR is different tube assembly.

sometimes folks also sell a used rear end if they switched to something different and it may already have been regeared.

personally not a fan of 3.73. There’s a reason Rubicons start at 4.10. Regular sedans have 4.10.