Lunchbox lockers?

Any recommendations on what locker to run in my k1500? I run stock gears and tire size with no lift. I just want to have both tires turning when I hit a mud hole. I know people hate on lunchbox lockers, but I think if it ever does break my axle I can upgrade axles and do a better locker

In the rear? Just weld it.

I hate lunchbox lockers with a passion. I had one for a year and it put me in some real sticky situations when it disengaged BOTH wheels. Granted that only happened when it was cold out but still, TX has been getting below freezing a few times in the winter recently.

Like thz71 said, lock it permanently, either weld it or do a lunchbox spool. Lunchbox spools may not be the strongest choice but it wont disengage unless it fails completely.

If its a factory G80 you're stuck with it unless you swap the carrier. You'll need an open carrier to run a lunchbox.

I looked at several lunch box lockers, for a long time. I kind of though I was going to get a powertrax no slip. Then my rear end started making a lot on noise. So I asked a bunch of people at the car shows that I go to, what they were running. Most of them said, an Eaton trutrac. One of them is using it in his 68 Mustang get 500. He is pushing 865 HP @ the rear wheels. Of course he is running a Ford 9 inch rear end. I also asked about rear end gearing. Running the 275/60/15 tires, and a 4L60E, they were all in agreement that I should go with 373 gears. Man we're they ever rite. It cost me about $1200 to rebuild my rear end my self. All new bearings, races, seals, carrier( the Eaton trutrac) oil, and even new wheel cylinders for the brakes. The trutrac works flawlessly. It is a true limited slip differential. It works on helix gears. There are no clutches to ware out, no springs, and you don't add the additive like you need in clutch systems. It is perfect for the street. If you use your truck for off road mostly, there may be better choices out there, IDK. Also, when I tore into my rear end, I had broker the bearing mount area off of the OE open carrier, so I would have needed another carrier anyway. Now, everything in my rear end is new. The only kicker was a week and a half later, I blew up the transmission. I had to have it rebuilt. I had a shop, do a performance rebuild. HD master rebuild kit, Corvette survos, shift kit, ECT. That was $2800. That was about a year and a half ago. It's holding up grate.

I was looking at lunchbox lockers to start because it was a cheap and easy option. The idea of the clunking when turning sharp on asphalt put me off. Also, I had read that the factory carrier is a weakness. Since I had to regear from the factory 3:43 to 4:11 for the 33" tires I went with the Eaton E-Locker and stronger axles at the same time. This way I have an open diff for the highway but can lock it up tight when in the soft stuff and not worry about breaking it.

The powertrax no slip works great, is reliable, and doesnt clunk around corners. A bit of a learning curve on acceleration and deceleration steering but I loved it in my old truck. I had 26 inch tall cooper cobra (muscle car tires mainly for street) and that truck did really good offroad and in snow because both rear wheels spun evenly.

The No Slip is stronger and quieter than the Lock Right.

The No Slip is more costly and a bit harder to install.

I don't know what spline axles you have. The 8.5 went to 30 spline in 1989 so here are your choices;


A Locker won't break axles. Spools, mini spools, and "Lincoln Lockers" (welded gears) will due to stress reversal around corners.
The Powertrax units will handle three times the torque than your axles will.

With stock tires and gears you won't kill your axles.
Giant tires and 6.14:1 gears and drive aggressively and you will snap axles like toothpicks.

Using this gear lube, https://www.summitracing.com/parts/red-58204 will make the lockers run quieter.

That is my go to goop for over 25 years. They use it in Top Fuel cars because it doesn't allow metal to metal contact.
That's why it quiets down lockers.

Wear gloves! That gear goop doesn't wash off easily and it smells worse than regular gear lube does.