How much to upgrade the rear diff and power towing mirrors?

TxCowboy · Oct 28, 2016

Just wondering -- any idea what it would cost to upgrade the rear diff on my 1500 from the 3.21 to the 3.92?

I assume I'll have to have it done at the dealership because they'll probably have to reprogram the computer because it changes the ship points on the A8 tranny.

Also, is it possible to replace the standard folding mirrors with the power towing mirrors? Anyone have this done and have a idea what that might run?

Thanks!!

drittal · Oct 28, 2016

Won't change anything with the shift points. If you get them changed you will have to have the speedo calibrated.

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TRCM · Oct 29, 2016

Why do you want to change the gears ? (N/M, just saw your other post)

If it is for towing more, do a search.....many many posts on this, and changing them won't make your truck able to legally tow any more.

If you bought it with 3.21 gears and a towing limit of 8k, then even if you put 5.13 gears in it, the towing limit will still be 8k.

Based on this post and your previous, you need a new truck with a bigger towing capacity, or get a smaller RV to tow.....changing gears will not solve your problem.

TxCowboy · Oct 29, 2016

TRCM said:
Why do you want to change the gears ? (N/M, just saw your other post)

If it is for towing more, do a search.....many many posts on this, and changing them won't make your truck able to legally tow any more.

If you bought it with 3.21 gears and a towing limit of 8k, then even if you put 5.13 gears in it, the towing limit will still be 8k.

Based on this post and your previous, you need a new truck with a bigger towing capacity, or get a smaller RV to tow.....changing gears will not solve your problem.

Boldfaced your comment above.

Am I to understand that changing the rear differential will NOT increase the towing capacity?

Maybe I'm misreading the chart on the RAM website under the "towing and payload capacity" guide, changing the rear diff from 3.21 to 3.92 increases the towing capacity from 7900 to 10,050 pounds. (Note: I'm looking under Light Duty - 6.4" box - 5.7L HEMI - Auto - 4x2.)

What am I missing?

drittal · Oct 29, 2016

TxCowboy said:
What am I missing?

Changing your gears won't change your truck's GVWR or GCWR.

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mtofell · Oct 29, 2016

It's a clerical thing - the numbers on the door are the end all no matter what modifications you make. Will it handle the load more easily? Yes. But, it's theoretically possible that if you were in a wreck and it was determined you were overloaded it could work against you. This has been argued about over and over on RV message forums for years and actual cases are extremely rare. But of course, it happens to people's sister-in-law's hairdresser's uncle all the time.

Aside from all of that, I agree you should be looking at the right truck for the job rather than trying the band-aid approach. I've done the whole maxed out 1/2 ton towing thing and it's no fun at all. Squishy tires, soft suspension and undersized brakes = white knuckles.

TRCM · Oct 29, 2016

TxCowboy said:
Boldfaced your comment above.

Am I to understand that changing the rear differential will NOT increase the towing capacity?

Maybe I'm misreading the chart on the RAM website under the "towing and payload capacity" guide, changing the rear diff from 3.21 to 3.92 increases the towing capacity from 7900 to 10,050 pounds. (Note: I'm looking under Light Duty - 6.4" box - 5.7L HEMI - Auto - 4x2.)

What am I missing?

You are correct. Changing it to different gears will not change anything except the money in your bank account.

What you are reading is true, but unless it was sold with the 3.92 gears, it will never legally be able to tow any more...unless you spend well north of 6 figures to get it certified as a custom vehicle.

The GVWR & GCWR are tied to your trucks VIN as it was built by dodge/ram....and nothing you can do short of recertifying it will change that.

It's cheaper to get a smaller camper or a bigger truck.

I looked into getting the truck in my avatar (a 79 ramcharger with a shortbed conversion) recertified as a 1 ton vehicle, since it had a complete 1 ton drivetrain......to do so would have cost me over $100,000, and it would have had to be taken completely apart and tested.

Simply not worth it. All because it was built as a 1/2 ton truck. Didn't matter that I had 1 ton running gear/engine/trans/brakes/t-case/suspension, etc......

TxCowboy · Nov 8, 2016

Thanks for the replies. Check my signature below for the response to your good advice.

EJR_3 · Nov 15, 2016

TxCowboy said:
Thanks for the replies. Check my signature below for the response to your good advice.

Nice upgrade

How much to upgrade the rear diff and power towing mirrors?

TxCowboy

Member

drittal

Senior Member

TRCM

USN, Retired

TxCowboy

Member

drittal

Senior Member

mtofell

Senior Member

TRCM

USN, Retired

TxCowboy

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EJR_3

Senior Member

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