limited Slip Rear Diff

[gpintler]

My brother is about to buy his 1st Ram -- 2015 long box with 3.42 axle ratio.

The build sheets say -- Conventional Differential Rear Axle.

Honestly -- how much trouble is it NOT to have limited slip or can you change out the Pumkin to a 3.42 limited slip.

My 04 has a LS diff but I can't say that I have ever been in a place where I have needed a LS diff.

Opinions Please.

 

[AH64ID]

Must be a 2500.

It completely depends on the driving he will do, but most people don’t need a LSD for where/how they drive.

 

[BigPapa]

It all depends on how he’ll use the truck. Is it RWD?

In my experience owning two 2nd Gen RWD trucks, the LSD helped pulling steep hills on gravel roads, and MAYBE a few times on hills in the grass. Other than that, unless he’s drag racing, it’s not a benefit at all. A tight LSD makes the truck practically useless in snow and ice. It’s next to impossible to take off without spinning, and unless you’re on PERFECTLY level ground, the back end is going down hill. I also found that the LSD is very hard on rear tires.

 

[lpennock]

Not hard to switch the carrier to a LSD. Easily within the capabilities of most shade tree mechanics. Hardest part is pressing bearings on. If he does decide to add an lsd, use a Eaton (Detroit) Truetrac rather than a stock AAM unit, much better unit.

 

[lpennock]

It all depends on how he’ll use the truck. Is it RWD?

In my experience owning two 2nd Gen RWD trucks, the LSD helped pulling steep hills on gravel roads, and MAYBE a few times on hills in the grass. Other than that, unless he’s drag racing, it’s not a benefit at all. A tight LSD makes the truck practically useless in snow and ice. It’s next to impossible to take off without spinning, and unless you’re on PERFECTLY level ground, the back end is going down hill. I also found that the LSD is very hard on rear tires.

My experiences with the torsen style diffs used in our trucks is exactly opposite what you say with the tight clutch pack units. I've found the back tires to have more even wear. I will agree if you break the tires loose the back will slide but I also find it easier to get moving rather than just sitting with one tire spinning.

 

[AH64ID]

It all depends on how he’ll use the truck. Is it RWD?

In my experience owning two 2nd Gen RWD trucks, the LSD helped pulling steep hills on gravel roads, and MAYBE a few times on hills in the grass. Other than that, unless he’s drag racing, it’s not a benefit at all. A tight LSD makes the truck practically useless in snow and ice. It’s next to impossible to take off without spinning, and unless you’re on PERFECTLY level ground, the back end is going down hill. I also found that the LSD is very hard on rear tires.

You really can’t compare the clutch pack style LSD (2nd Gen) to the helical gear style (03-18). The helical gear LSD is a far superior design and works fantastic in snow and ice.

Of all the things I’m excited about on the ‘22 I’ve ordered there is one thing I’m not looking forward to and that’s the clutch style LSD that Ram/AAM went back to for the 19+ trucks. We’ll see how it does on snow/ice as my experience with clutch style LSD’s is the same as yours and I’d rather have a open diff. In fact I was all set to remove the LSD when I bought my 05 until I learned it was a helical gear LSD.

 

[Ozymandias]

Has Eaton a replacement Truetrac for the 12" available now?

 

[lpennock]

Has Eaton a replacement Truetrac for the 12" available now?

No just the AAM 9.5 and 11.5.
https://www.eaton.com/content/dam/e...ormance-differential-application-guide-en.pdf

 

[BigPapa]

Good to know. When I bought the ‘98, I thought the clutches had been restacked to make it tighter, but when we rebuilt the rear axle a few years ago, everything was still the factory setup.

 

[kthaxton]

I thought a LS was standard with a Cummins?

 

[p-Bar]

One wheel drive sucks. I had countless times on jobsites and my own property that I would sit there and spin. At 65 years old I finally bought my first 4wd love it.

 

[AH64ID]

I thought a LS was standard with a Cummins?

Optional on 2500's and standard on 3500's.

 

[NIsaacs]

I thought a LS was standard with a Cummins?

It was an option on my 2500.

"Anti–Spin Differential Rear Axle $445"

 

[Boaring1961]

IMO, the LSD on my 2018 is WAYYY better than the LSD I had in my 2005.

 

[Jim W]

My brother is about to buy his 1st Ram -- 2015 long box with 3.42 axle ratio.

The build sheets say -- Conventional Differential Rear Axle.

Honestly -- how much trouble is it NOT to have limited slip or can you change out the Pumkin to a 3.42 limited slip.

My 04 has a LS diff but I can't say that I have ever been in a place where I have needed a LS diff.

Opinions Please.

BUT what is the ROI benefit on the LS diff? Is he willing to spend the money for this feature and will he get the cost out of the LS diff over the length of time that he keeps the truck? That is what he needs to decide on.

 

[Ozymandias]

If someone drives loaded most of the time I think it works fine without, empty driving not so much.
To much torque from that engine for a single unloaded tire to provide traction.

But that's my opinion.

 

[gpintler]

Thank you all. If it is a problem in the next year we will just go aftermarket and slip one in.

 

[jkern]

Had a '99 with clutch pack style, it was worthless stock. i restacked it pretty tight, it was great in gravel, grass, field, and a little extra when in the mud; but on snow and ice it was too tight. It also did wear the tires much quicker. After i re-stacked it, i consistently got 5-7k miles less life from my tires. My 2011 has the stock LSD and it works pretty well in most situations.

 

[verk]

I've heard others say that Detroit Truetrac exhibits more lash than factory LSD in these trucks and when combined with a manual transmission it feels very sloppy (didn't see OP indicate transmission). My '04 manual with open diff already feels very sloppy and in combination with very poor traction in slippery conditions has had me thinking about upgrading or at least fixing for a long time. If others here have manual transmission with LSD of any kind I would appreciate hearing their experiences. Eaton application guide here.

 

[Ozymandias]

Eaton Truetrac has no lash at all, you are talking about a Detroit Locker which has quite an amount of backlash.