Rear differential help

1

12vtwin

diesel enthusiast
Joined
May 4, 2015
Messages
24
Hey guys, so I've been riding the old girl pretty hard lately and have noticed on a few occasions now that when I stepped on it a little too much in 2wd my right rear tire only starts spinning..No spin out of the left tire. I'm thinking my rear dif is on it's last legs? If that is the case, what is a good upgrade for the stock dana 80 posi in the single wheel 2500? I am 561/1089 at the rear wheels uncorrected right now but plan on taking that to the 700/1400 range soon. This truck is a daily driver, manual trans, 3:55 gear, 35" tires. Thanks in advance!
 
I favor Detroit lockers for the strength and simplicity but there are other options out there as well.
 
For the time being drain out the gear oil, clean off the clutches with spray brake clean and fill with regular 90weight without the friction additive. The additive is there to make the clutches slip. If its to aggressive and chirps the tires when turning add the additive a little at a time until you like it.
 
You could also remove the diff clutches and restack them friction steel friction steel etc instead of the less aggressive factory setup with only two or three stacked correctly for posi traction.
 
Big Blue24 said:
You could also remove the diff clutches and restack them friction steel friction steel etc instead of the less aggressive factory setup with only two or three stacked correctly for posi traction.
Click to expand...

I'm kind of interested to know more about this.
 
It doesn't require a special tool but if you want to add a second steel and clutch you need to modify a socket to press the pack together tighter. This has been done for a generation or so. The stock configuration is steel, steel, clutch. Change it to steel, clutch, steel, clutch and add a second set and you've essentially made a locker. Rebuild kits for the D80 LSD are just over $100 last time I priced one out.
 
whitneyj said:
The stock configuration is steel, steel, clutch. Change it to steel, clutch, steel, clutch and add a second set and you've essentially made a locker.
Click to expand...

By locker do you mean spool? Can't you change the preload to tune the clutch engagement characteristics?
 
You should find a factory service manual for the restacking, assembly.
This only applies to the second gens too. The AAM axles don't use clutches.
TheD80 can be made very tight and can make the tires act locked in corners so be careful.
 
dpaqu said:
By locker do you mean spool? Can't you change the preload to tune the clutch engagement characteristics?
Click to expand...

Potentially? I've never tried.

I wouldn't call it a "spool" at this point as there's still slip, just not much under any sort of power, so it's still a "locker" of sorts.
 
Detroit locker. Just put one in my dana 80, daily driver.

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Dammit... I just rebuilt my power-loc and wish I read this first. I would have restacked them steel, friction, steel friction. I thought it was odd how the OE did it but figured it was to make it less aggressive. For my purpose of being a dedicated tow pig, it is probably fine in OE config.

These were my old clutches.
2015-06-07%25252009.40.48.jpg


2015-06-07%25252009.40.34.jpg
 
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You don't want it to lock too early or under power with a tow rig. That'll make quick work of your center pin, LSD clutches, shafts, yada yada yada. It's a good thing you rebuilt it to stock.
 
I have a locker in my truck I never notice it during turning. Its fine in parking lots etc...
 
It's honestly just fine. I really don't notice it unless I wanna feel it, AKA stay on the throttle around a turn.

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