I have a detroit trutrac in my street/track car. One of the benifits/downsides is the power transfer. On dry pavement, torque is almost perfectly split. But if one tire loses all traction, you don't go anywhere.

That's a big plus in racing. I broke an axle one day. With a factory type LSD, it would have sent a lot of power to the unbroken side. That causes the car to make a hard turn. Instead, my car gently rolled to a stop. No power at all to the unbroken side.

That would make me think that if one wheel was on pavement, and one on the ice, you wouldn't go anywhere. Maybe that's not a good thing in a 4x4 truck?

Maybe that's what happend to your son's truck. One tire had no traction on wet gras. That wheel got all the power.

 

If you apply a little brake in the same condition you can get the other tire to spin. Sort of like doing a brake torque but for a different reason. I have even heard some that will apply the parking brake slowly until the other tire starts to move then once you are back on common gound release the brake. I would rather have the trac-rite gears than clutch packs to replace.

 

As mentioned, ARB is supposed to be releasing an air locker sometime in Q1 '09.

At least that's what the US president emailed me 2 months ago.

Tony

 

Well after doing all service work today on my 03 it is apparent that I need a new carrier (posi) and ring and pinion. After searching for an ARB which there is none yet then went to auburn with no luck, then tried eaton, with the same results. It looks like I'm gonna have to go with the factory setup again and hope for better luck this time. It just kinda seems like they don't make the good stuff for us big boys yet. As for LSD I perfer auburn. I've had better luck with the cones than the clutches.

 

Have you thought about getting an entire rear end from a Powerwagon and just replacing it as a whole?

The cost *should* be comparable to parts/labor of the ring/pinion/seals/carrier and as a bonus you get an electrically controlled Locker.

Food for thought.

 

Powerwagons have a 10.5 not the 11.5 that most of our CTDs came with.

 

No haven't given it any thought but I would rather have a 11.5 to a 10.5.. I checked through dodge and it looks like I can probally get away with just under 1500 in parts for a full rebuild.

 

I've been having my differential "AAM TracRite" act funny for several years now. It is stated you don't have to use friction modifyed lub in these but I'm starting to wander if they may work better with it. I've been running Mobile 80W-90 synthetic sence the first oil change at 30K.
Mine will lock if both tires are on equil type terrain. If the right tire is in dirt and the left on pavement it will try to lock for a moment and spin the left tire briefly. With the left tire in the dirt and the right tire on pavement it will stay locked and spin them both. At the drag strip it will spin them both comming out the water box and then quite frequently unlock and just spin the right tire.
It's claimed these 11.5s in the Dodges don't have clutches and don't need friction modifiers but I'm thinking some friction may be needed to get these things to lock up. Mine seems to have been getting worse for the last 40K miles and it may be from parts getting polished from wear and the oil with high film strength. Every time I changed the oil there were no parts or shavings in the oil and the oil looked too clean to be changing.
Billy

 

Friction Modifiers reduce the coefficient of friction - make the oil slipperier (is that a word?). That allows the clutchs to slip a little bit, and not chatter during operation. Adding it to a non-clutch type diff won't hurt anything. Probably won't help, either.

 

Well I drained off some oil and added 2 4oz bottles of friction modifier. We'll see what happens.
Billy

 

Well I'm using Amsoil Severe Gear 80w90.My first tow with that fluid pulling about 10k after a hundred miles or so when starting off from a stop I had a NASTY shudder in low gear.After a little cool down it would go away.Also a CHRIP on left turns hot from a stop.I pulled drive shaft and put in joints.Old ones were like NEW inside.Wasted time and money.Then I had a tech at the Dodge dealer check drive line angles with trailer hooked and unhooked.In specs and not on the border,but in the preferred area.Then I did a lot of using the SEARCH function.Found a OLD similar post.Fixed it with a bottle of anti chatter additive(not suppose to need!)then I called some rear axle shops,two of them that did stock and custom work.The said use ADDITIVE even tho no clutch packs.Then I added ONE bottle of Purolator(I think)additive from Auto Zone or what not.Darn FIXED it in a few miles.No chirp on left turn and I've towed several times since with no shudder on take off.Something not SLICK enough in the Amsoil fliud! The other posts I found still had Factory fliud in them.Go figure.

 

Synthetics are for sure superior.Group 4 synthetics are much more stable and slicker,longer lived then non synthetics by far.Something in the formula I guess. The answer is in the brew I think.The answer/reason why a few of these axles do that with who evers fliud I'm sure can be explained.I just don't know where to find that answer.

 

Well the friction modifier added didn't help. It made it worse. So from the looks of the oil I drained off it's time to change it out. With only running 30-40K miles on the oil I don't see the need for the expensive synthetics and going to refill with dino oil."No friction modifier"
Billy

 

The AXEL MANUACTURE says SYNTHETIC FLIUD.No where does it say its ok to use non synthetic fliud.Every body uses SYNTHETIC fliud.Well MOST everbody.But what ever.If a little posi additive made it worse I would think you have a bigger issue.