Ok so one of my best friend's is looking to buy a 2009 Laramie 4X2 and he's found a few with everything he wants including color but they are missing one MUST HAVE...the 3.92s with LSD. My truck has it as a factory option and I know it's a $375 factory option but does anyone KNOW what it will cost or has cost them to upgrade from 3.55s to 3.92s with the LSD? OTD prices is what I'm looking for.

Also, not knowing a lot about gear replacement, he's wondering if in replacing the 3.55s with 3.92s, is it a "complete replacement of the rear differential, or do they just insert a different gear"?

Thanks in advance!!
Jason

 

They just change the ring and pinion. On a 4x2 it ought to cost $700-$900 if a shop does it. Who knows what a dealership would charge.

 

if your friend hasent bought it yet then tell him to tell the dealership to do it for the 375. its that simple

 

That's what I was thinking but I wanted to see if anyone had had a dealership do it. My truck didn't come with the MOPAR Chrome Tubular Side Steps and they're a $655 option from the factory but my dealer only charged me $695 for them installed which I thought was fair.

Jason

 

Make the gear change the "deal maker". Besides, you want the dealer to do it to preserve the drivetrain warranty on the diff.

 

The gear ratio part is just a ring/pinion swap. The LSD part is a whole new differential.

New differential plus new ring/pinion + labor is a lot of money. But, at least it's two wheel drive so it only needs to be paid once.

 

Probably a question for the dealer, but from my understanding it's more involved than a ring and pinion swap. I believe the LSD is operated by a computer that applies the brake to a spinning wheel so the other one will drive. Also there is an on/off switch on the dash along with an idiot light in the instrument panel. Sound like he needs to keep searching to me.

 

no, what you are talking about is ESP (traction control). The LSD is an actual differential. It will still work when esp is turned off.

 

I just figured out how the LSD works in offroad conditions and why I'm lucky to have it on my TRX4. One wheel in the air.... the ground wheel will push me along....nice..

 

Inbred is right. BTW all the new Rams have the ESP traction control as per gov't requirements.