AAM 11.5, carrier gears damaged

[AH64ID]

Exactly, I hate plate LSD's with a passion based on them being totally unpredictable on ice/low traction. . especially on a slightly off-camber FS road with 6" of snow on it. The helical is great in that kind of driving, you just have to be a little more careful when/where you stop.

 

[steved]

Exactly, I hate plate LSD's with a passion based on them being totally unpredictable on ice/low traction. . especially on a slightly off-camber FS road with 6" of snow on it. The helical is great in that kind of driving, you just have to be a little more careful when/where you stop.

What's unpredictable about a plate style?? You know it will break both tires loose, and will head whichever way the road is crowned... I don't see that as unpredictable.



I'd take a worn out Dana 80 Trac-Loc over this AAM Trac-Rite any day of the week... I have never liked it, and find the idea of being hung more of a concern than it being "unpredictable"... I've probably got close to a million miles on the old style plate LSDs... never once did any one of them mysteriously do something I didn't know it was going to do.



And if you think about it... I apply power on ice and it spins (while rolling down the road)... by the definition provided in earlier posts, an AAM LSD isn't going to slip both tires on ice how???? Its stated that it works best rolling... rolling and applying load. Its going to behave the same way as any other LSD on ice. You guys are stretching the imagination thinking it doesn't...



Further, I find the AAM LSD more UNPREDICTABLE on ice because you never know if one tire is going to spin or if both tires are going to spin... at least with my plate-styles LSDs, I knew both tires were going to spin predictably.



Not to mention, you can adjust the preload on the Dana 70/80 LSDs to make them as aggressive as you want... try that with a AAM.

 

[AH64ID]

What's unpredictable about a plate style?? You know it will break both tires loose, and will head whichever way the road is crowned... I don't see that as unpredictable.



I'd take a worn out Dana 80 Trac-Loc over this AAM Trac-Rite any day of the week... I have never liked it, and find the idea of being hung more of a concern than it being "unpredictable"... I've probably got close to a million miles on the old style plate LSDs... never once did any one of them mysteriously do something I didn't know it was going to do.



And if you think about it... I apply power on ice and it spins (while rolling down the road)... by the definition provided in earlier posts, an AAM LSD isn't going to slip both tires on ice how???? Its stated that it works best rolling... rolling and applying load. Its going to behave the same way as any other LSD on ice. You guys are stretching the imagination thinking it doesn't...



Further, I find the AAM LSD more UNPREDICTABLE on ice because you never know if one tire is going to spin or if both tires are going to spin... at least with my plate-styles LSDs, I knew both tires were going to spin predictably.



Not to mention, you can adjust the preload on the Dana 70/80 LSDs to make them as aggressive as you want... try that with a AAM.

Well in that regard its predictable, but as far as moving traction on anything but ice it's not predictable. . other than it seems to help when you don't need it, and doesn't when you do.



The helical gear design puts power to both wheels when moving but doesn't have the lateral traction issues of a clutch-plate LSD.



The AAM has always worked perfectly for me on snow/ice/mud/dirt/etc, as long as I am not stopped in a deep snow situation its excellent. I know it will give me good power, but not kick me sideways when I don't want it to.



I will take an open diff any day over any clutch-plate LSD.

 

[jrgough]

differential additive

I changed the fluids about 10,000 mile ago with mopar 75/90 and now have some funky popping when i cross a small swall or ditch. i did not add the additive beacause it said not should I? Will it hurt if I do? Should i go back with 75/140 gear oil? I do not see any leaks also.



i just check my window sticker from when I bought it and it said i have anti spin 11. 5 axles

 

[steved]

I've used three different fluids, only one of them has required additional LSD modifier.



Regardless of what they state, some fluids will cause chatter which feels like two pieces of rubber sliding past each other in turns (under load). Adding it won't cause any problems... I've been running 4oz of Mopar additive for the last 50k, and sit at 250k.

 

[jgillott]

I've started getting a popping sound out of the rear of my '07 especially in a slow speed tight turn in a parking lot etc. I've got a little vibration at highway speed every once in a while. I've been trying to convince myself that the vibration is a tire out of balance or the like. Seeing those gears like that make me worried what I'm going to find when I get in there. The fluid in mine isn't that old, but I'll probably change it out again this weekend to see what it looks like in there.

 

[llotton]

I don't understand what some are saying here. In the late 70s in a Blazer we installed a "Detroit" true trac in both diffs. . As a test we jacked both axles off the ground and put jack stands under three corners with only the left front on the ground. I then engaged four WD and proceeded to drive the veh. off the jack stands. This I know because I did it. Perhaps they have changed the unit in the interim years.

 

[mpaulson]

There is no clutches in these, so the additive is not required and has nothing to add friction to. The end of the day cost came to $2800. 00 to put in a tru trac carrier and all new bearings in for the pinion and the carrier and a new seal. :{

 

[steved]

The Trac-rite does have clutches, they are termed "brake shoes" in IPL diagrams from what I remember... they operate a little different than a plate style or "real" helical.

On edit:

Now that I'm sitting in front of my computer... the Trac-Rite isn't a true helical LSD, it appears sort of like a hybrid between a clutch style and helical. I think that's what causes the most confusion is that its incorrectly thought to be the exact equivalent to the Detroit True-Trac. From what I can understand from the IPL diagrams and its description in the FSM, it seems to operate similar to a helical LSD but forces the "brake shoes" (friction material) together causing the friction which translates into the slip limiting force. The reason some have LSD chatter in the Trac-Rite, is because of the brake shoes (your friction material) grabbing just like a clutch type LSD. And the reason they don't have any slip limiting action from a standing start is that they appear to have zero preload on the brake shoes... the tires have to initially rotate at different speeds in order to cause the Trac-Rite to function.

Hopefully that makes sense...

 

[BIGNASTY]

Are we overlooking Amsoil the BETTER snake oil :-laf a guy at work swore by Amsoil and always had some kind of gear prob. front / rear/diff. transfer case always something but it was the best oil to him and he was paying the repair bills so I agree its the best

 

[BIGNASTY]

I changed the fluids about 10,000 mile ago with mopar 75/90 and now have some funky popping when i cross a small swall or ditch. i did not add the additive beacause it said not should I? Will it hurt if I do? Should i go back with 75/140 gear oil? I do not see any leaks also.



i just check my window sticker from when I bought it and it said i have anti spin 11. 5 axles

Get the VIN and call Dodge NOT the STEALERSHIPS, but Dodge and they will tell you if you need the additive or not. I have used 75/90 Chevron NO ADDITIVE

 

[steved]

Are we overlooking Amsoil the BETTER snake oil :-laf a guy at work swore by Amsoil and always had some kind of gear prob. front / rear/diff. transfer case always something but it was the best oil to him and he was paying the repair bills so I agree its the best

I hope not, I just bought some Amsoil 75w90 Severe Gear for my Forester XT! :-laf

 

[AH64ID]

Are we overlooking Amsoil the BETTER snake oil :-laf a guy at work swore by Amsoil and always had some kind of gear prob. front / rear/diff. transfer case always something but it was the best oil to him and he was paying the repair bills so I agree its the best

I have always used Amsoil in all my diffs/trans/xcase and never had a lube related issue, and in my dads older auto trans chevies (700R4, 4L60, and now a 4L80E) they have always lasted longer than most and done well. I have no doubt that there was some driver abuse in your buddies case, Amsoil lube is pretty hard to beat.

 

[BIGNASTY]

I dont think that the pic in the #1 post was done by ANY kind of gear lube but I do think that allot of people put allot of stock in oil/additives/and other snake oil products. Hell even I do I use Amalgamated fuel additive and love the stuff. But talk to some people from TEXAS and its snake oil thats his opinion and thats what matters to him. Amsoil is just as good if not better than what I use I have used Chevron for a very long time WHY because it was FREE I do like their products with the exception of the Grease I have been using Valvoline Palladium and think it is hands down the best grease on the shelf and I have 4 cases of Chevron Black Pearl on the shelf in the shop. So if you are willing to pay the difference in price and think its better then go for it only time will tell and that is why I look at all the different posts and products to find out.

 

[amsoilman]

There is no lubricant that is going to damage one component in a gear box, and leave all the other gears in good shape! Has anyone given any consideration that perhaps the metal the gear was made from was defective?

 

[BIGNASTY]

NO IT HAS TO BE THE AMSOIL ! just kidding but if your statement is true wouldnt there be a whole lot of this going on. Im sure that it wouldn't be just one.

 

[AH64ID]

It's probably not just one, and probably a defective part. I bet most people/shops don't look that close on fluid changes.

 

[steved]

It's probably not just one, and probably a defective part. I bet most people/shops don't look that close on fluid changes.

I remember seeing pictures posted some years back that looked a lot like the OP's... same gear damaged. Oil had nothing to do with that failed part, or there would be obvious signs of oil-related damage throughout.



It happens, even with good quality control a bad part sometime slips through the cracks. Think about the 9. 25 Corp Trac-Loc in the 1500 Ram, it has a known issue with retaining clips breaking and causing all sorts of havoc. That same LSD had been used in countless Dana applications and was pretty reliable up to that point.

 

[DGamelin]

Well I am at a 126k and my second posi is coming apart again, just found small pieces in there again. I am going to put an open carrier in this time. I have had enough.





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93 250 2wd xcab 354 auto 286k

04. 5 3500 4wd cc dully 373 6speed 126k

 

[mpaulson]

Update, since I did the diff, I have pulled the bottom plug about 6 times and each time I have found what looked like a bunch of small metal matter compressed into what looked like chunks!! Tonight I pulled the bottom plug (it has a magnet on it) and it had a few more chunks and one of them is a piece of a gear! I have talked with the shop serveral times and they were just in the hubs a few weeks ago doing the seals and the hubs and bearings were good. I have had the cover off several times myself and done a clean out of the crap in the diff. It seems odd that pieces keep appearing. What sucks it with the true trac, it doesn't have the holes in the carrier unit to see the gears like the oem one did in my original post, so how is one to tell if these are new pieces, or just reminants of the old one that are hiding and coming out of the axle tubes or something? yet I don't know where they would be coming from unless they were in the axle tubes and the shop didn't clean them out, but I wouldn't think they would get there in the first place. I've only got about 12,000kms on it since the rebuild and about 4 oil changes!!! If I have to replace the carrier again, it will be a plate style. I have to admit that I'm thinking of going with oem oil to eliminate that issue from the equation. Next step will be retro fitting a diff in from the 5500 trucks that will handle being used like a truck should be able to. This diff is obiously sub standard since on the new Max Tow trucks, they upgraded the axle on the 3500 truck which tell me that Dodge knows that the diff can't hold up to the loads of those of us that push their trucks at the top end of the load spectrum.