Lockers

[Blazer Ralph]

FYI, just something to consider.

All selectable lockers, when locked, act like a spool. So essentially the rear tires are locked together as one axle. When unlocked it acts like an open diff. But this means when locked it may want to push the truck straight in some offroad situations if you have more traction in the back than the front.

A Detroit locker is different. Many people assume it automatically locks, which is not really the case(that is the case with a G80 "gov lock"). What the detroit locker and many lunchbox lockers actually do, is they are usually locked and they automatically unlock. Think of a ratchet, each side works like a ratchet and can spin faster than the ring gear, but not slower. So if you go around a curve the outside tire that wants to spin faster can disengage and spin faster. The moment it stops spinning faster either from going straight or applying more power than the inside tire can hold, then it catches and is under power again.

The drawback to that is there is a little more backlash so the cam can switch ratchet directions when you put it in reverse. This can be harsh sometimes, for example if you go around a curve or change lanes under power and you let off during that maneuver it can go from driving the inside tire to engine braking on the outside tire.

So a selectable can be either be a spool or open, whereas a Detroit is in between and in a way both at the same time, something the selectable cannot do.

Either way, having all power available to one axle means that axle needs to be strong enough to take all the torque.

Anyway, just helping you decide what's right for you.

Thank you for this info, I don’t like the idea of a Detroit locker just because of the turning situation and seems like it will be a lot harsher on my rearend. I think I like the idea of the ox locker because I can turn it on when I actually need it and less stress on the rear end.

 

[formercruiserhead]

love my good working G80 rear in 14ff . tried a detroit for 1 winter and took it the hell out . sucked a$$ in the snow daily driving . had to have it in 4wd to go in a straight line in more than 2" of snow .

I had my front driveshaft out and made a 5 mile trip in 2wd with a Detroit rear. Scariest 5miles of my life. Would not turn it just pushed you straight on snow covered streets.

 

[Barrman]

Another personal experience Detroit Locker warning. I put one in the rear of my M715. I had a 396 Big Block in it then with a NV4500 5 speed. Depending on tire pressure I found I could change lanes just by jumping on or off the throttle in 3rd gear around 35 mph with the steering wheel never moving. Very unsettling.

Then I tried towing another M715 on a trailer in the rain. I have never been so scared in a vehicle before or since. I made a set of block out plates after that adventure so if I ever got in that situation again I would pull 1 axle shaft from the full float D70 rear axle, install a plate to keep the oil in and just drive with 1 wheel drive. If that didn’t work I planned to pull and block off the other rear and try front wheel drive. Anything had to be better that rear locker in the rain with a trailer.

Putting a 6.2 diesel in the M715 after I broke the 396 made the locker much more friendly to drive. Less power equals less excitement.

I have to write though that a locker in the rear is amazing when traction off road is needed.

I have a G80 equipped 14 bolt semi float in my 3/4 ton Suburban. Perfect towing manners in any weather and as described in several post in this thread already. Great off road in loose stuff as long as you give it a little throttle to get the locker engaged. Too much spinning and it won’t work right. I actually practiced in some mud in 2wd just to get a feel for it. I love the G80 in that axle.

All of my M1009 trucks have the 10 bolt G80. Even with a 6.2 diesel I have read too many horror stories to even practice engaging the G80. Aired down tires, 4 lo and thinking my way through before I get into a situation is how I drive them off road.

 

[Chickntrk]

Sooooo if you don’t think you want a Detroit I dunno that I’d recommend a lunchbox locker. My lockrights are way more noticeable than my Detroit.