Engine/Transmission (1998.5 - 2002) Axle/Diff info, Powr-Lok?

[rspinks]

Can't remember the proper #'s but my service manual refers to the different Ram rear axles as something like 9. 25, 248x, 268x, 286x. 9. 25 is obvious but what about the other 3, are these Dana 60, 70 and 80? What about the "Hybrid" 70/80? And the big question: Who is lucky enough to get the Powr-Lok instead of the Trac-Lok??? Looks like the Dana 70 to me, but I have a hybrid so I get the Trac-Lok? Wahhh, I want the 4-pinion Powr-Lok!:{ It's one of the best and strongest LSD's available.

 

[Bugman]

Dave Fritz's page has some good axle info:



http://www.dodgeram.org



Bugman.

 

[tarussell]

The 248,267,and 286 are the metric sizes to the Dana 60,70 and 80 ring gears. The Dana 60 can come w/ the Trac-Lok one piece case and two pinion gears. The Dana 70 comes w/the Powr-Lok two piece case four pinion design and the Dana 80 comes w/ the Trac-Lok two piece case and four pinion gears.



The standard Trac-Lok [one piece case and two pinion gears] for the Dana 70 was not strong enough. At least Spicer made a stronger Trac-Lok for the Dana 80 since they were not going to offer the Powr-Lok. In case you are interested , it is possible to put a Dana 70 H. D. Detroit Locker into the 80 if the ring gear bolt holes are enlarged to the 80 size. DO NOT get a locker for a regular 70 they are not the same. The 70's that I am talking about have the letters H D casted into the housing , four inch dia. axle tubes and huge carrier bearings just like to Dana 80.



I hope this helps.....

 

[rspinks]

Tarussell thanks for the info, you read my mind because I went through this axle obsession with my '94 gasser and ended up putting a Detroit in the Dana 60. Nothing hooks up like a locker when you need it, I kind of miss it and find the LSD somewhat useless offroad. I went to Trachtech.com and found some interesting Detroit Locker information:



1. They show 4 different locker part numbers for Dana 70, 1 for Dana 70HD and one for Dana 80 (4. 10 and up only).

2. They make a TrueTrac for the Dana 80. I thought this was a small-axle device only. I like the gear-driven design vs. clutch plates, and I think it will still torque-bias with one wheel off the ground, not sure.

3. They list the Dana 80 as 11. 5" ring gear, Fritz says 11".

4. They show the Dana 80 having 1. 52" instead of 1. 50" axle shafts, while Fritz has both at 1. 50". Both are 35 spline shafts, is this a typo or are they different shafts



I love axle and diff stuff.

 

[tarussell]

rspinks I agree w/you about the True-Trac. I thought it was for the smaller diff's too.



I have seen many publications that state that the ring gear size for the Dana 80 is 11. 00" and 11. 50" but Spicer only list the metric size,so I did the math and it comes out to 11. 259842". That sounds like 11. 25" to me.



As far as axle dia. we should have 1. 50" 35 spline axles in our trucks. I have seen larger axles in G. M. 3500H. D. [old body style] 1. 625" 37 spline and Ford f-450's. I can't remember what the Ford spline count was but it was BIG.



The carrier split for the Dana 80 is between 3. 73 and 4. 10,but I have seen catalogs that list an offset pinion for the Dana 80 so they are not all created equal.



I'll bet the reason for the locker listing only showing a 4. 10 and up carrier is for sales reason's[not enough people w/the other ratios buying lockers--not cost effective to make].



I hope this helps. I like all this axle and gear stuff too.

 

[MJawsman]

I was told by Randy's Ring & Pinion that it's really a Torsen diff not a True-Trac. I guess Torsen is the brand in the Hummer and from what the guy told me, it's huge and looked bullet-proof. That's the unit I was thinking about trying if I go to a limited slip unit.

 

[rspinks]

Reading the service manual last night and they say 11. 25" ring gear diameter for the D80. I guess Fritz rounds down and Tractech rounds up . Sounds like we have relatively small axleshafts for the ring gear size, don't some Dana 60's come with 1. 5" 35 spline axles?



I wouldn't be surprised if the True-trac was licenced from Torsen, it sounds similar in design. I remember reading in Road&Track about 15years ago when the Torsen first came out, they thought it was a great invention.



That's very interesting that the Hummer has the Torsen style diff, it must work pretty well to be used in that application. Perhaps this is the magic diff that is better than a clutch-type LSD but not as brutal on the street as a locker. My main complaint with the LSD is that it will easily spin one wheel on ice or when off the ground.