Open diff or Power lock?

[fisherman]

Yesterday I was out to some friends property in the foothills. I attempted to climb a rather steep rutted driveway in reverse, only because of the lack of room to turn around. I made it almost to the top when the bed started bouncing, both tires were spinning and then the rear started to slide off the road. I tried this twice with relatively low speed in reverse, each time I had two tires spinning. I ended up turning around and driving up it forward in two wheel drive. The same thing happened it looks and feels like there is something other than an open diff in the rear of my truck. I stopped on the hill going up and rpm'd up a little and dropped the clutch again I had traction coming from both tires, pretty evenly. Although you could tell which tire started to spin first and which tire had the most traction. Do open diff's do this? Or is there a power lock in there? I posted a picture of my open rear diff a couple years ago and everyone said it was open. I just figured if it was open diff I would have only had one drive tire and been able to keep the truck straighter climbing the hill due to only one tire spinning. Maybe I should repost my picture?

[fisherman]

There I found it. Open diff? or not. Since I can't tell by looking at the picture and I'm not ready to remove the rear cover yet.

[dahoyle]

Certainly looks like a 2 piece open diff from the picture, but it is possible that it has a Detroit installed it the stock carrier. I would think that you would be able to hear it clicking on dry pavement if it were a detroit, tho.

[bor]

Call Memphis Equipment and or send them the pic. They will be able to confirm one way or another. memphisequipment.com

[fisherman]

I took a look at the power lock in the shop and it definately looks different. I don't hear or feel anything on the road. I'm confused. I guess I need to do some more severe wheeling to figure this out.

[fisherman]

For those in the know? If I jack the truck up and spin a rear wheel will a detroit show itself? And what should I look for. The gear guy who will be setting up my diffs is a long drive. I don't want to take it all the way down there if I already have something installed. It's been so long since I've had a Jeep to drive I don't remember the characteristics of a locker or power lock.

[ryanroo]

For those in the know? If I jack the truck up and spin a rear wheel will a detroit show itself? And what should I look for. The gear guy who will be setting up my diffs is a long drive. I don't want to take it all the way down there if I already have something installed. It's been so long since I've had a Jeep to drive I don't remember the characteristics of a locker or power lock.

it should. might not seem like it at first, but if its a detroit it will spin both after a revolution or so. a d70 usually with open carriers you have good visual of the spiders/side gears. with that one being so closed in it makes me think it is some form of traction aiding diff. i am not very familiar with the 715 variant of the d60/d70, so i may be all wet.

and with it spinning both backing up a hill, it seems like it would have locker or limited slip. in that condition the weight is all on the front of the truck, and would make it really easy for just one to spin.
Ryan

[dahoyle]

a d70 usually with open carriers you have good visual of the spiders/side gears. with that one being so closed in it makes me think it is some form of traction aiding diff.


Ryan

D70 open carriers come in two flavors. 1 piece and 2 piece. The 2 piece carriers have 2 cross pins and 4 spiders, much like a powrloc. I don't think that they are quite as common as the open style that you are describing, but they certainly aren't rare, or limited to 715 applications. The 2 piece carrier is similar to the 14 bolt carrier, in that you don't have to replace the entire piect to install a Detroit. Most of the 2 piece carriers are in fact, open, and if it is what was originally installed in his truck, then it was open.

[ryanroo]

well, i am no expert on rear ends, so i believe you. my experience is more with GM rear ends in most flavors. but now i know, thanks for the info
Ryan

[brute4c]

If its an open diff, you can spin one tire and the other will go in the opposite direction.
Locker, both spin the same direction.

If you want...jack up one rear tire and try to turn it while the othr is down, by hand...if you can, open diff. If you cant, locker or posi...if you can with difficulty and the other one doesnt move, posi with wear.