Hi,

New here and didn't find what I was looking for searching so far.

I have a 77 W100 I have been rebuilding (rebuilt eng, electrical, etc so far) and need some help with differentials.

It is full time 4 4wd and from what I understand it has Dana 44 front, Chrysler 8.25 rear.

When I originally bought the truck I was told it had "posi" (which I assume to mean limited slip) in the rear. I put it up on a rack and it operates as an open differential. Everything seemed to be orginal at purchase as the truck had exactly 100k miles and all records with it.

Is it possible I burned the clutches out (the first weekend I had it I ran through deep snow for several hours and abused it really bad) and that it causing it to act as an open differential or was it not one to begin with?

I am trying to figure out the most cost effective but durable way to get limted slip/posi (I would only want posi/lockers on the rear as it is full time 4wd and I do not want to change the hubs to manual) on both the front and rear.

I live in extremely rugged country and this truck spends 75% of it's time off pavement. The snow depth and terrain have been really tough the last couple hunting seasons and I think having LS/POSI would really make a difference and save me a lot of shoveling myself out of drifts.

Any input would be appreciated.

 

How about a selectable locker? Most limited slips wearout after time. A quality unit like and Auburn may last longer or you could get a gear limited slip like a Detroit trutrac (if available for your axle). Usually though even with the gear drive units when you really need them they will let you down. This is all from what I have heard though. I only have factory posi experience and those are usually very pathetic.

 

The 8.25 has a distinctive flat bottom on the pumpkin casting with a 10 bolt elongated circle pattern. Limited slip was an option in the 8.25. Chances are you don't have limited slip. Even if the clutches are bad both wheels will generally still turn in the same direction when not under load. If it is limited slip and you can't afford a locker you can rebuild it for about $100.00. If you are using it the way you describe I would recommend you step up to a true locker in the rear only.

http://www.4wheelerssupply.com/catal...9de080&x=0&y=0

 

Thanks for the replies.


If I put a Detroit in the back and a selectable such as an Auburn in the front do I need anything other than the differential and standard install parts? Basically trying to determine if I can still use my factory ring gears, etc.

Looking at something like this:

Front
http://www.ronsmachiningservice.net/...OK-POSI/Detail

Rear

http://completeoffroad.com/i-123210-...and-older.html

 

Both of those have limitations on the gear ratios. What ratio is in your differential? Have you ever set up a ring and pinion? Once you know your ratio you should call them and talk about the set up procedure and any special tools that you will need. They may send you a set of installation instructions so you can decide if you want to tackle this or if you have to have it done.