Locking diffs

[AH64ID]

I agree with Ozy. The OEM helical gear LSD is hands down the best LSD I have ever used, and I have used a few. Based on my experiences in the the late 90's and early 00's I was so sick of the crap LSD's on the market that I was going to have the OEM LSD in my 05 removed in favor of an open differential until I learned it was a helical gear setup. Aside from the low engagement at a stop it out preforms every LSD I have used and operates like an open diff on slick ice and doesn't reduce lateral traction (unlike any clutch pack LSD).

The GM may be called a GovLoc but it's not a locker. It uses a governor and fly weights to apply a clutch pack. Teminology is important. Throwing the term locker around causes a lot of confusion.

With enough differential rpm the Gov-Lok does lock the wheels together. It is a locker, just not a very good one IMHO.

I have driven plenty of miles with a Gov-Lok to know that I really, really, dislike them. In addition to differential rpm they also like to lock (mainly due to clutch pack tension) on low traction surfaces, which is not fun if that surface is a off camber snowy/icy forest service road with a big drop off.

Just as Henderson said about the GovLoc above, the AAM Torsen is not a locker, it is a limited slip. A locker and a limited slip are not the same thing.

He was referring to the Power Wagon locker, and it is exactly as he described. It's a helical gear torque sensing limited slip that has an e-locker option. It's a great unit, and now that it's available for the 11.5" axle I may have to research putting one in.

 

[jhenderson]

Please tell me how a clutch type diff is a locker. Locker implies a mechanical engagement that allows no slippage. Clutch type diffs have clutches in tension from springs for the specific characteristic of slipping under extreem bias. One precludes the other.

 

[AH64ID]

Please tell me how a clutch type diff is a locker. Locker implies a mechanical engagement that allows no slippage. Clutch type diffs have clutches in tension from springs for the specific characteristic of slipping under extreem bias. One precludes the other.

It doesn't have to be black and white. Just like a clutch with a manual transmission, it can slip, be disengaged, or locked up.

With the appropriate wheel speed differential (been a while, but 100 rpmd comes to mind) the Gov-Lok will lock the tires together.

 

[kthaxton]

He was referring to the Power Wagon locker, and it is exactly as he described. It's a helical gear torque sensing limited slip that has an e-locker option. It's a great unit, and now that it's available for the 11.5" axle I may have to research putting one in.

His first sentence implies he is talking about his truck.....which I assumed is not a PowerWagon since I do not see it in his profile. Therefore I assume he is talking about a typical Torsen Limited slip that the rest of us have. Also, I am with henderson, a limited slip is not a locker.

 

[jhenderson]

And clutches are there to provide slip. Doesn't matter if it's a GovLoc, Traclock, or Ford. The factories put in clutch type diffs to allow for decent street manners.

 

[Ozymandias]

To my understanding neither the Gov-Loc nor the AAM-Torsen uses Clutches, so they are not Limited Slip.

 

[AH64ID]

The AAM does not use clutches but rather helical gears to provide the torque sensing action. This is why it's a great LSD, but it is not a locker. The Power Wagon gets helical and e-locker in one unit.

Clutches aren't what define a LSD, but rather what level of torque splitting happens between the tires. If you want a good example of how the OEM LSD works on 3rd and 4th gens lookup a Detroit TruTrac. Lots more info on the TruTrac than the AAM but they are nearly identical in theory and operation. There are some minor differences but the principle is the same.

The Gov-Lok is a different ball of wax all together. The Gov-Lok does have clutches but also a centrificaly driven locking mechanism that locks the rear.


ktahxon, yes I missed the word locker in the first sentence. It's not a locker in these trucks from the factory.

 

[Flash1034]

Either way, Ram should offer at least a real rear wheel switchable locker as an option. When you need it...you need it.

Flash

 

[kthaxton]

...and then there is a third type of LS, the Cone clutch (i.e. Auburn LS) that uses the friction of cone shaped gears and springs.....also not having a clutch pack.

 

[DonFitzwater]

I've hated the AAM "anti-spin" differential (that's what Ram calls it) since they came out. I've yet to have a truck that seems to work even marginally with the exception of my new hemi powered 3500 chassis cab dually. Not sure why in the heck this one works so good but it must have something to do with the duals and added traction of another tire. My srw trucks would just spin one tire on the ice and not go........that torque biasing diff has to have some sort of resistance on the side that's slipping or else it won't transfer any power to the other side..............most folks recommend applying light parking brake pressure but that never worked either.

My little 1500 with a Corporate rear and a limited slip goes places AAM anti-spin equipped trucks can't unless they are in four wheel drive. Hell, even a lowly Toyota Tacoma that ended up in my driveway for a couple of years had a locking diff. Ram needs to step up.

 

[Flash1034]

That's been my experience too with the worthless limited slip Ram puts in their trucks. I can remember being stuck in a snow bank and only one tire spinning in the rear. Hopefully the next gen Rams will get a real locker option.

Flash

 

[AH64ID]

Not sure what you guys have going on, but the AAM LSD is the only LSD I have ever used (been thru many, many others) that actually works as advertised.

Thet don't like to work from a dead stop but with any wheel speed they work better than anything else out there.

Then again almost every LSD complaint is about an LSD that doesn't work like a locker... Weird, considering they aren't lockers... Nearly all LSD complaints are from people who don't understand how they operate.

I am a big fan of selectable lockers; however, for the way that greater than 99% of owners use their pickups there isn't much of a point to an OEM one in a HD pickup. I use my truck iM more backroad/off-road stuff than most and in over 100K miles I could have used a selectable locker once and even then it wouldn't have helped as much as I needed.

 

[griggsd]

ARB selectable lockers are available for AAM front & rear axles in our trucks. Haven't personally installed them on my 2013 yet, but will as I enjoyed 210K trouble free miles on my prior 00' with Dana 60/80 axles.

 

[Ozymandias]

That's been my experience too with the worthless limited slip Ram puts in their trucks. I can remember being stuck in a snow bank and only one tire spinning in the rear. Hopefully the next gen Rams will get a real locker option.

Flash

A little push on the service brake and both tires spin.

You just dont know how the torsen system works. Sorry

 

[Flash1034]

A little push on the service brake and both tires spin.

You just dont know how the torsen system works. Sorry

Guys, I've been Jeeping for 30 years...you can equivocate that a limited slip is "as good" or "works great" but a real selectable locker is the real deal and can get you out of a bind unlike any limited slip. Make it an option. If you limited slip guys wanna stick with it, you can, but a real locker would be oh so nice to have.


Flash

 

[AH64ID]

It all depends on how the vehicle is used. For a trail rig selectable is the best option, but for a tow rig a helical LSD is better, IMHO.

Having done a bit of wheeling I have some experience with ARB's and know the benefits, but this truck just isn't used like my old Toyotas were.

Now that there is a AAM helical/e-locker for the 11.5 my wheels are turning...

 

[DonFitzwater]

Not sure what you guys have going on, but the AAM LSD is the only LSD I have ever used (been thru many, many others) that actually works as advertised.

Thet don't like to work from a dead stop but with any wheel speed they work better than anything else out there.

Then again almost every LSD complaint is about an LSD that doesn't work like a locker... Weird, considering they aren't lockers... Nearly all LSD complaints are from people who don't understand how they operate.

I am a big fan of selectable lockers; however, for the way that greater than 99% of owners use their pickups there isn't much of a point to an OEM one in a HD pickup. I use my truck iM more backroad/off-road stuff than most and in over 100K miles I could have used a selectable locker once and even then it wouldn't have helped as much as I needed.

You sound just like the service manager at my local dealership. He didn't understand either until I had him back my truck into an icy dip in the parking lot and watch one tire spin......all day long. He tried to apply brakes, parking brake......couldn't get out until he put it in four wheel drive.

I have zero issues in dirt where there is some available traction for one tire, my problem is on ice and contrary to the global warmer types, we have plenty of it here in Alaska.

 

[AH64ID]

I have no issues on ice, and we get plenty of it too. In fact I love this LSD on ice since it doesn't lose lateral traction like lockers or clutch style LSD's. Sometimes 4wd is needed, but that was also the case on my trucks and a SUV that had a selectable locker. I've owned 3 rigs with selectable lockers and there honeslty isn't a substitute for 4wd.

Helical gear LSD's do operate a little different and need a little wheel speed and traction to do their best; however, they still do better than other LSD's.

I know mine isn't an anamoly as there are three of them in my family. Two 11.5's and. 10.5 between myself, my dad, and my brother.

If you are dead stopped they don't like to engage, but neither do any other LSD's. If your stuck or stopped and need that extra traction choices are selectable or selectable... along with 4wd.

I had a stuck 8K trailer last winter and even with as little at 3-4" of movement the AAM would provide traction more often than I expected.

Like I said earlier, it just depends on how you use it. For most users the AAM Helical LSD is far more than needed.