Differential options & comments

[TStinson]

This has probably been asked before, but didn't have time to research thru all the posts.

My ride is a 2006 CTD 2WD Quadcab SWB 48RE automatic with AAM open differential 3.73 gearset, and am pondering installing some type of differential upgrade to help eliminate the one-tire drive, 1/4 mile burnout ability Dodge unbelievably blessed this truck with.
I know there are a number of options ranging from the stock AAM helical LSD setup, to the other end of the spectrum with a spool.
Neither of these seems to be what I need, and I would welcome informed (meaning having experience with the various types available) comments from members who stumble across this post.
The end use of the truck is as a daily driver, with occassional drag strip visit, and generally used to shock the unsuspecting who think pawpaw's truck is a leadsled.
Currrent upgrade is a Smarty s-06 with current software. Best 1/4 mile time/speed to date is 14.67 @ 96.5 mph with slug-paced 60' of 2.48 (basically have to roll into the throttle until well into 2nd gear - cannot takeoff hard at all due to open differential).
There are too many differential options and one-sided comments out there, I'm hoping to get some good suggestioins from TDR member who have played-the-field so to speak, and have experienced the different setups.
I am planning to start adding more goodies to make this Ram a real sleeper/shocker, but realize that all the power in the world is useless with extremely-limited traction, so am starting there.

Any serious suggetions/comments are welcome.

 

[Bob4x4]

I have been very happy with my OEM lmtd slip,get on it hard and there are to stripes-do it in a turn and you will get sideways

 

[jhenderson]

An air or E locker is my 1st choice. Next and only other option for me would be a Tru Trac.

 

[Ozymandias]

ARB Airlocker is also available, proven solid Design can handle high HP.

 

[BDaugherty]

The OEM limited slip would probably work great for your use. If you can't find a deal on one, get a true trac. Ifor my application, i have not been real impressed with my factory LSD. I would like to have a locker...less the giant price tag. With larger tires and under harder useage, the stock LSD just isn't strong enough to pull both tires when I meed it most.

 

[lpennock]

No compare between a factory helical limited slip and a truetrac. Factory LSD is only a 2:1 torque bias while the truetrac is 3.5:1. This means that for ever 1lb of torque available on the low torque side the truetrac will put 3.5lb of torque to the high torque side. When I had the factory unit I could easily break one wheel loose in the rain with the truetrac both wheels break loose.

Driving the truetrac doesn't feel any different than the stock LSD, it just provides better traction. I sold my stock LSD for $350 so you should be able to pick one up around that price but I would recommend skipping the stock unit a go to the truetrac.

 

[p-Bar]

I second the ARB air locker

 

[lpennock]

I'll be the the descenting voice on any selectable locker. (ARB, E-Locker, etc). If the primary reason for the locker is to give off road performance and still give good street manners the selectable lockers are hard to beat. But, If the primary purpose is to give improved traction under all conditions the selectable lockers aren't that good a choice. When you need improved traction in rain, light snow, etc the selectable lockers don't help because they are an open when unlocked. For all condition traction improvement the truetrac is the better choice.

I'm not anti selectable locker but one needs to way off when traction improvement is required and if the desire is to improve traction in all conditions the truetrac is a better choice. If the purpose is extreme off road performance with stock open diff street manners the selectable is the best choice.

 

[thashane]

Looking for options myself, I was hoping auburn ected would be available for the 11.5 but I dont think they can handle the torque. Also it seems like things that try to do two things never seem to do either as well as one that only does 1 thing.

Now the question is helical or clutch type.

 

[lpennock]

Now the question is helical or clutch type.

Who makes a clutch type? I think your option is helical, Detroit locker, or selectable.

 

[Prairie Dog]

I have been very happy with my OEM lmtd slip,get on it hard and there are to stripes-do it in a turn and you will get sideways

Same here. Mine works flawlessly.
I had some work done by a local diff shop. He drives a 1T Chev and told me he not only replaced the clutch type LSD in his truck with an AAM Locker but also does it for customers all the time.

 

[TStinson]

Forgot to mention that this truck has the 10.5 AAM rear axle.

 

[lpennock]

You sure about that. I believe all diesels had an 11.5.

 

[jhenderson]

All after 04 for sure had an 11.5

 

[AH64ID]

Forgot to mention that this truck has the 10.5 AAM rear axle.

Your truck has a 11.5" AAM, all diesels has the 11.5" from 2004 on. Only some SO trucks had the 10.5" in 2003.

Clutch style LSDs should be discontinued, and I'd rather have an open diff. I was actually going to have my OEM LSD removed for an open diff until I learned it was a helical style. Clutch only work when the shouldn't, and reduce lateral traction. I have yet to drive any vehicle with a clutch LSD where the LSD didn't reduce performance.

So your viable options are OEM, Detroit TT, or an ARB.

I have ran ARB's and love the locker, but unless it's a dedicated track truck they have no real world 2wd application. Get the TT or OEM, whichever is cheaper.

 

[TStinson]

Well ... I really want to agree with all of the comments about how it has to be an 11.5, but .....
The cover has the 10.5 bolt pattern, and the VIN decoder I found on the DodgeForum.com site says it has the 10.5 rear axle, so what else could I check to know for certain which size it really is?
At this point, I guess the next step is to go by a local differential shop and see what they can tell me.
Since I am a firm beliver that Murphy is alive and well .... it won't surprise me to find that I have a truck that was supposed to have received a 5.7 hemi ... but lucked out and got a CTD dropped into it.

 

[AH64ID]

What is the size of the axle tube?

How about a pic of your diff?

I found enough errors on the VIN decoder just now to say I wouldn't trust it at all.

The base axle for a 2500 is 10.5", and probably why it says that. The base GVWR for a 3500 is 11,500", on a base 2wd, which is what it says my GVWR is. My GVWR is 9,900#.

My dad has an 06 2500 CTD and the standard equipment lists 10.5", but it has the 11.5".

 

[Ozymandias]

Yes a picture would help greatly.

 

[Bob4x4]

With the last 8 of the vin I can see the options/build sheet

 

[TStinson]

Nott he best photo, but should let you see what you need.

What is the size of the axle tube?

How about a pic of your diff?

I found enough errors on the VIN decoder just now to say I wouldn't trust it at all.

The base axle for a 2500 is 10.5", and probably why it says that. The base GVWR for a 3500 is 11,500", on a base 2wd, which is what it says my GVWR is. My GVWR is 9,900#.

My dad has an 06 2500 CTD and the standard equipment lists 10.5", but it has the 11.5".