Open diff or limited slip
Im changing the rear axle on my 99 4x4 2500 Dodge to a dually Dana 80 I can get an open differential or a factory limited slip Ive had a 03 4x4 Dodge dually with open diff and my SRW truck now has ...
Forum Discussion
okan,
I've had plenty of lockers and limited slips in rigs and each style has it's place. My jeep at one time had a Lock Right rear and a Power loc front which worked pretty well. When I was over on one of the Dodge Diesel sites, there was plenty of discussion about which one to get if you are hauling a heavy load (like a camper). Here are the results:
Every pickup should have at least a limited slip type rear diff. There are many contenders, but the main ones for a Dodge are the infamous Trac-lok (aka: trashlok) which has a set of wet clutches that have little preload. The woe is they don't last carrying a heavy load. My estimate is 50-70K miles before rebuild. I got 70K out of the set on my '80 Scout Traveler TD. Only about 55K from the ones in various XJ's i've owned (and still do). There is a slow degradation over time and in the end you have little more than an open diff. Most people don't even notice the lack of traction and just live with it until they sell. My current XJ has a Trac-lok and is acting like an open diff at about 20K miles. Changing the oil and using more additive helps bring it back, but not all the way.
The other one, the one that won the Dodge Diesel lottery over Detroit, Loc Right, and all the others is the tried-and-true Power Loc. It too has wet clutches but they are slightly cone shaped like finger cymbals and are under a pretty good preload, so they don't give up easily and are pretty transparent. They were used by the Military during the 1970's and 80's on Dodges as being the most trouble free. I've had mine in the pig for 6 years and have had one oil change. The fish oil lube wears out before the clutches do, unlike the Trac-lok which just wears out.
The main thing is the Power-loc is the only one that will hold up under a long term, heavily loaded pickup. The very hard 'shock loading' of the true lockers makes them a non-contender as they won't last and have quirky banging and steering woes. I know, the sainted Detroit Locker? Yep, the self-same. The nature of a full locker is to oversteer under engine acceleration and under steer upon deceleration. It's the joint between the two where you get the herky-jerkys. I got used to it in my Jeep using Detroits and Lock Rights but it can be a caution on ice. Like anything else, you learn to live with it or try a new route.
Yes, when unloaded, my Power-loc is so tight (adjustable by preload shims) the inside wheel will chirp when accelerating around a sharp corner from a stop. But, it has gotten me to just use 2WD a lot when I could be in 4WD as both wheels keep on-a-churning back there, even with those super singles.
If you have had good luck with a Track-loc, well, God bless you.
The other choice, albeit most expensive, is a selectable locker like the ARB air locker (my jeep has those front and rear) and for a Dana 60 the cable operated OX Locker. I have no experience with the Eaton open/limited slip/full locked, but the blow up diagram looks pretty complicated to me. I had a friend with a Gov-lok and it went quite a ways in his 3/4 ton chevy van before the cross shaft snapped. AAM axles are supposed to have a limited slip available (at least on their website) but i have not seen one in-the-flesh. Any of you with an AAM axle speak up if you have a limited slip about it's operation and longevity.
regards, as always, jefe
I've had plenty of lockers and limited slips in rigs and each style has it's place. My jeep at one time had a Lock Right rear and a Power loc front which worked pretty well. When I was over on one of the Dodge Diesel sites, there was plenty of discussion about which one to get if you are hauling a heavy load (like a camper). Here are the results:
Every pickup should have at least a limited slip type rear diff. There are many contenders, but the main ones for a Dodge are the infamous Trac-lok (aka: trashlok) which has a set of wet clutches that have little preload. The woe is they don't last carrying a heavy load. My estimate is 50-70K miles before rebuild. I got 70K out of the set on my '80 Scout Traveler TD. Only about 55K from the ones in various XJ's i've owned (and still do). There is a slow degradation over time and in the end you have little more than an open diff. Most people don't even notice the lack of traction and just live with it until they sell. My current XJ has a Trac-lok and is acting like an open diff at about 20K miles. Changing the oil and using more additive helps bring it back, but not all the way.
The other one, the one that won the Dodge Diesel lottery over Detroit, Loc Right, and all the others is the tried-and-true Power Loc. It too has wet clutches but they are slightly cone shaped like finger cymbals and are under a pretty good preload, so they don't give up easily and are pretty transparent. They were used by the Military during the 1970's and 80's on Dodges as being the most trouble free. I've had mine in the pig for 6 years and have had one oil change. The fish oil lube wears out before the clutches do, unlike the Trac-lok which just wears out.
The main thing is the Power-loc is the only one that will hold up under a long term, heavily loaded pickup. The very hard 'shock loading' of the true lockers makes them a non-contender as they won't last and have quirky banging and steering woes. I know, the sainted Detroit Locker? Yep, the self-same. The nature of a full locker is to oversteer under engine acceleration and under steer upon deceleration. It's the joint between the two where you get the herky-jerkys. I got used to it in my Jeep using Detroits and Lock Rights but it can be a caution on ice. Like anything else, you learn to live with it or try a new route.
Yes, when unloaded, my Power-loc is so tight (adjustable by preload shims) the inside wheel will chirp when accelerating around a sharp corner from a stop. But, it has gotten me to just use 2WD a lot when I could be in 4WD as both wheels keep on-a-churning back there, even with those super singles.
If you have had good luck with a Track-loc, well, God bless you.
The other choice, albeit most expensive, is a selectable locker like the ARB air locker (my jeep has those front and rear) and for a Dana 60 the cable operated OX Locker. I have no experience with the Eaton open/limited slip/full locked, but the blow up diagram looks pretty complicated to me. I had a friend with a Gov-lok and it went quite a ways in his 3/4 ton chevy van before the cross shaft snapped. AAM axles are supposed to have a limited slip available (at least on their website) but i have not seen one in-the-flesh. Any of you with an AAM axle speak up if you have a limited slip about it's operation and longevity.
regards, as always, jefe
