913A561 Trutrac Differential with 31 Spline for Ford 8.8"

The differential itself is awesome. It's amazing how it's unnoticeable it is until you need it. None of the drawbacks of a lunchbox locker, but plenty of the advantages. I drive my truck pretty hard sometimes, even on the street and around corners it acts just like an open diff until the inside slips. You feel it just briefly as the power moves to the outside and carries you through. No crazy locking or wheel hopping, chirping or anything else to upset the balance, it just stays nice and smooth and carries you through with control. I love it, even in the rain it improves normal day to day driving as you miss the occasional slip as you go around corners with too much throttle or climb a steep turn. Offroad and light snow it does wonders as well, it's just so transparent and pulls you through most things quite nicely. You can easily put both left tires on ice or mud on the side of the road and take off just on the grip of the right just like you're supposed to be able to. Definitely helps keep speed in low traction environments. Be sure to get new carrier bearings and a shim kit (the Yukon kit is great Yukon (SK SS12) Super Carrier Shim Kit ). You'll definitely need a press for the carrier bearings as it's a tight fit, I wouldn't risk damaging a bearing trying to use a hammer. It takes 2 minutes with a good press, so even if you need a shop or a buddy to do it, it's worth it. The gears and abs ring on the old carrier came off with a hammer and pry tool pretty easily and can be driven to the new carrier with the bolts, easy peasy no press needed. A little grease or prussian blue helps mark the gears to ensure proper alignment, also a dial indicator for backlash. I replaced the axle bearings and seals at the same time, they were a breeze to pull with a slide hammer even on my old truck. A new diff cover and gasket isn't a bad idea either, they're cheap. I didn't touch the gears or forward parts on the differential. I think it took me about 4 hours start to finish taking my time, I was surprised how fast and easy it went.

Does not lock consistently, I shoulda went ARB

Update: I'm a couple years in now on this diff, and it's been flawless. Lots of street miles, countless drag strip passes, over 930rwh, and a 9.90@145 in a 4,000lb GT500. I'm about to upgrade to 33 spline, and I'll be going with a truetrac again. I've run many of the gear diffs currently available, and this TruTrac is the best, hands down. It's incredibly strong, absolutely quiet, and easy to install. So far with this diff I've run a 10.30@137 in a 3950lb GT500. I've also autorossed with it, and put many street miles on it, all with flawless results. I highly recommend this diff to anyone. It's a pretty amazing piece of hardware for the money.

Replaced the clutch pack type differential with this unit which never required a rebuild. Runs quiet and lockup is very quick. Glad I'll never have to go back in for maintenance like with the oe unit.

This thing is awesome. Expensive, but it does everything it claims!

Sends both tires up in smoke on the street but no ratcheting or banging like the competitor around parking lots or turns. Cant wait to hit the 1/8 mile this summer, I'll update then... I upgraded to this unit from a stock ford 8.8 limited slip

Wow! This Detroit Locker is worth every penny I spent on it! I put it on my Ford F-150 pickup truck with 6-cylinder engine. What a difference it has made! I now have traction like never before! I highly recommend it. Also, the Locker fit very well on my truck. Was pretty easy to install, too.

This thing works great until a tire comes off the ground. if your wheeling... apply the parking brake slightly and it will stay locked in