@012 Limited slip

[Animal]

I just picked up my 2012 3500 CC with max tow. I changed out the rear tires for my winter tires and the rear diff acts like it has one wheel wonder not limited slip like the window sticker said. I turn one wheel counter clockwise and the other tire goes clockwise.



Is there a new limited slip out there that does this?

 

[LNaugle]

That ls is a helical gear style i believe, and proper way to chck it would be both rears off the ground and trans in neutral and turn the shaft yourself...

 

[cerberusiam]

All the AAM LS diffs act like that. It is a TQ bias limited slip not a posi.

 

[Animal]

Thanks for the replies. I didn't know helical gears did that.

 

[Bob V]

It's more than just helical gears. It was covered in a recent TDR magazine. They are a good design but wont work if one of the tires has zero traction (load). When this happens apply the parking brake a little and it will help get to axle "locked".

 

[Wygate]

I have a 09 that never seems to "find" that 2nd wheel. Fixed it tonight, called Dave Smiths to try again

 

[AEdelheit]

I've never had an issue spinning both tires, the helical grad LS seem to work well.

 

[Bob4x4]

I love mine it works awsome.

 

[AH64ID]

I love the helical gear design. I am not a fan at all of the clutch style limited slips, they work when you don't want them to and don't work when you want them too. I have had more sliding from clutch style LSD's and prefer not to run them anymore. In fact I was going to remove the LSD when I bought my 05 until I learned it was a helical gear design. The helical gear design is the only one I have ran that tracks true in ice, especially off camber and slick forest service roads.

They don't work as well when stopped as a clutch style, but the rest of the time they are much better.

 

[Wygate]

Seems to me that a standing start is when it sure would be nice to have, I. e. merging in to traffic w/ trailer in the rain, parking lot in the snow, steep driveway w/ mailbox stop, ranch/farm work in wet grass, god help you if you get in 1" of wet silt... I guess I am in the minority w/ the desire for the more aggressive LS
Never the less I am trying it again, didn't someone say something about doing the same thing over and over expecting different results?

 

[Prairie Dog]

I love mine it works awsome.

Me too. Mine works flawlessly.

 

[AH64ID]

Any motion on both wheels makes the helical out preform a clutch pack, IMHO. A dead stop where your traction limited is they fall back, but I have yet to have a scenario where it has caused me an issue. I have had the truck stuck in the snow and the loss of traction is equal and they both spin.

 

[seafish]

I run my 2005 LS on my steep gravel road and off road on grass all the time... it seems to work flawlessly for me... only once or twice have I needed to tap the brake while starting to go to get the second wheel to engage on gravel.

 

[Wygate]

If mine worked like you guys I wouldn't have broken my front drive shaft. 2 wheel drive in about 8" of snow on gravel, only one rear would spin, 4 wd still only could get 2 to spin. I was cross ways on the road and some pushed up snow and the crown of the road held me firmly in place. As I worked the wheel I heard a dull thud, got out and checked the axle joints expecting to see the short side broken. I saw nothing, got back in back in gear and another thud. Looked under the truck this time from the side and shaft was hanging down.
I tied it up, used my winch to slide the front back on the road and drove the few miles home to put her in the barn to get a better look.
Broke the slip yoke ear down into the barrel of the body of the slip yoke, also snapped 2 ears off the u joint, on flush w/ the cross body the other half way down the bearing surface area.
I have just resigned that it is a Friday afternoon build we will see w/ the new one tomorrow!

 

[AH64ID]

It sounds like you were stuck, which makes the helical gear loading difficult. Only 1 spun on the front because it's a open diff up front. Depending on how much traction the wheel that wasn't spinning had applying the ebrake or service brakes a little can load the diff enough to get torque to transfer.

Working the wheel hard while spinning tires can easily lead to broken parts, as you found out, especially if traction comes and goes.

 

[Wygate]

It sounds like you were stuck, which makes the helical gear loading difficult. Only 1 spun on the front because it's a open diff up front. Depending on how much traction the wheel that wasn't spinning had applying the ebrake or service brakes a little can load the diff enough to get torque to transfer.

Working the wheel hard while spinning tires can easily lead to broken parts, as you found out, especially if traction comes and goes.

I started off turning around, walking out my turn before hand to keep out of trouble ie big hole, ditch ... . got half way through when I couldn't climb the crown of the road, the back would not engage both no matter what I did, yes I am aware and used the brake to help transfer power. I am also we'll aware of the open diff in front. I build trucks from diffs to roll cages, you could not have known that.
I have a winch (hitch mounted) for just this case, not to keep me going down a trail, just for piece of mind when alone
I am just saying I know diff better than most, I have been inside all types, clutch, gear,air spools and open so I have a better idea than most of what and how it should preform. Took apart my first gear LS to see what was up, broken gears. I have more experience w/ the old gov-llock than I care to reveal,
that was a great one until u got some wheel speed and then got traction.
Any way, that's enough, leaving to get the new truck 12 Mega cab 6. 7

 

[AH64ID]

Hey, a new truck sounds like more fun than a broken drive-shaft

I too carry a hitch mounted winch for piece of mind, and it's been handy a few times.

The gov-lock was a good unit on flat ground, but it worked too good on slick off-camber stuff and would cause the rear end to walk downhill which on a 1 lane road isn't ideal. .

Be sure to pist up some pic's of the new truck! Are you keeping any goodies off the 09 for it?

 

[Wygate]

Hey, a new truck sounds like more fun than a broken drive-shaft

I too carry a hitch mounted winch for piece of mind, and it's been handy a few times.

The gov-lock was a good unit on flat ground, but it worked too good on slick off-camber stuff and would cause the rear end to walk downhill which on a 1 lane road isn't ideal. .

Be sure to pist up some pic's of the new truck! Are you keeping any goodies off the 09 for it?

They want a stock truck, so everything but the Fass stays w/ me, 30 gal of fuel in her short notice on the trade so= too much hassle to put it all back, that tank is a hand full empty and no time

 

[Wygate]

Got the new Mega cab, just drove back from Idaho, and the LS works much better big diff just between hotel and Dave Smiths.
She ran great on the way back, me on the other hand, got food poisoning! As long as the truck keeps running good!

 

[PLohr]

How many of you that prefer the AAM 11. 5 factory differential have 4WD? My truck is 2WD and has been stuck in soft sand and mud. A vehicle with poor weight distribution, poor suspension geometry, and springs that are too hard to absorb any shock from quickly applied torque will get stuck in the silliest places. This could be avoided with a clutch style differential.

AAM says to use the emergency brake to get the left rear tire to drive. Some of you have suggested this. I have tried it. Please take a minute to consider the logic behind this. For this to work, the right rear emergency brake has to engage before the left rear. Otherwise the right rear continues to drive and bury itself. Of course the e-brake is intended to apply equal pressure to left and rear. If this works, it is coincidence and not design. A separate lever to apply pressure to only the right rear e-brake may correct this.

If the truck is moving and the right rear breaks loose, the left rear will then takeover and break loose. By then I have let off the throttle. This happens on wet pavement quite a bit. I would trade this for both tires driving from a dead stop. AAM has admitted that both rear wheels need to be turning at a slow rate for its differential to work as they intend. That can't happen when stuck in mud or sand.

This AAM 11. 5" differential cannot be an inexpensive piece. The benefit is so low that Chrysler could have just as well used an open differential in my truck.