2017 Ram 1500 gear swap

[Jim Guyton]

Hello,

I was hoping for some help with the gear swap on my truck. I picked up a 17 Ram 1500 3.6 with the 8 speed trans and was told it would pull 7000 plus pounds (Only reason I was ok with the 3.6 v6) but I sold my RV and was going to buy a tow camper and now I'm finding out that I have the 3.21 gears and it will only handle 4200lbs. I did find that I could of got the same truck with the same drive train and 3.55 gears to get with the 3.6 to be able to pull 7000 plus lbs. I have sourced a full rear setup and front center section from the same year with 3.55 gears. The questions I have are:
1. Do I need new front axles also or just the center section?
2. If I do the swap will the computer pick up on the swap or will my speedo be off and or will I have a check engine light that I will have to deal with?
3. Will I have to have it reprogrammed by the dealership?
4. And will just a gear swap pick up 3000lbs. extra towing lbs.?

 

[U&A]

From experience.

Save some time on the internet searching and show up in person to a place that can actually do the work. Talk to them about what you want.. see if they’ve even done it before on that year of your truck or if they know what is needed.

Use a good calculator like this to find out what gears you really want and you can see if they make what you want. In my opinion I would not do such a small jump in gears. I would jump up to 410s even with that eight speed. JMO.

http://www.grimmjeeper.com/gears.html

Its all about being in the optimal RPM range at the speeds you will be driving when towing.


Sent while firmly grasping my redline lubed RAM [emoji231]

 

[Brandon-w]

2 wheel drive or 4?

 

[Wild one]

2 wheel drive or 4?

I'm guessing he's 4X4 as he mentions front axles.
The deepest you can go with the ZF front diff is 3.92,and you'll need to buy the complete front diff to get the gears,as the ZF front diff is a non-serviceable diff(ring gear is welded to the carrier).If it was me,and you want to tow upwards of 7,000lbs behind your 3.6,i'd start searching the want ads/local market place ads etc.,and see if you can hunt up both diffs from a wrecked truck.They aren't that hard to change on a driveway if you have a decent selection of hand tools /impact and floor jack.Line a buddy up and you should be able to swap both diffs easily on Saturday. Your axles and front diff actuator will swap over to the new front diff

 

[Jim Guyton]

I'm guessing he's 4X4 as he mentions front axles.
The deepest you can go with the ZF front diff is 3.92,and you'll need to buy the complete front diff to get the gears,as the ZF front diff is a non-serviceable diff(ring gear is welded to the carrier).If it was me,and you want to tow upwards of 7,000lbs behind your 3.6,i'd start searching the want ads/local market place ads etc.,and see if you can hunt up both diffs from a wrecked truck.They aren't that hard to change on a driveway if you have a decent selection of hand tools /impact and floor jack.Line a buddy up and you should be able to swap both diffs easily on Saturday. Your axles and front diff actuator will swap over to the new front diff

First off yes 4x4. And I was able to find a front diff and a complete rear end from disc to disc for $15oo.oo same year with only 37k miles on them also running off of a 3.6 v6. do you think it will need to be reprogrammed for the larger gear set?

 

[sheets7777]

Yes you will have to set it / program it to account for your new gear ratio. Atleat I did, even when just changing tire size on another vehicle.

 

[PoMansRam]

Another 2017 3.6L 3.21 owner here.

It does seem unreal that this small of a ratio change increases the tow rating that much, but that's what FCA says. It was the reason my brother went with the 3.55s when he purchased his pentastar powered 2019 Classic. Ridiculous thing is, it was only like a $60 option per the sticker to have the 3.55 ratio. They are not the easiest find, but if you type "3.55" into the dealer's website inventory search, you'll find'em. Other than that you have to walk the lot. Never rely on what the sales team tells you.

Honestly, before I spent a few grand on a 2017 for just swapping differential ratios, I'd look into trading in for a 2019 classic with 3.55s.

 

[crackerjack1957]

If ya want to pull the wet string out of the cat's ass look for the 3.92.......LoL

 

[RedSRT4Me]

Hello,

I was hoping for some help with the gear swap on my truck. I picked up a 17 Ram 1500 3.6 with the 8 speed trans and was told it would pull 7000 plus pounds (Only reason I was ok with the 3.6 v6) but I sold my RV and was going to buy a tow camper and now I'm finding out that I have the 3.21 gears and it will only handle 4200lbs. I did find that I could of got the same truck with the same drive train and 3.55 gears to get with the 3.6 to be able to pull 7000 plus lbs. I have sourced a full rear setup and front center section from the same year with 3.55 gears. The questions I have are:
1. Do I need new front axles also or just the center section?
2. If I do the swap will the computer pick up on the swap or will my speedo be off and or will I have a check engine light that I will have to deal with?
3. Will I have to have it reprogrammed by the dealership?
4. And will just a gear swap pick up 3000lbs. extra towing lbs.?

All this talk about gears but is your wheel and tire setup? That will also effect the ratio if you're putting on a larger than factory setup.

 

[RLJ10X]

I'd look a little longer and do 3.92s.

 

[Jim Guyton]

All this talk about gears but is your wheel and tire setup? That will also effect the ratio if you're putting on a larger than factory setup.

Wheel and tires set up will stay factory. 20" factory wheels and factory tires

 

[Wild one]

First off yes 4x4. And I was able to find a front diff and a complete rear end from disc to disc for $15oo.oo same year with only 37k miles on them also running off of a 3.6 v6. do you think it will need to be reprogrammed for the larger gear set?

You should be okay swapping the gears with-out reprograming.Changing tire sizes will screw things up,but a lot of us who've done gear swaps have never had to reprogram the truck.If it seems to shift or act funny,then you might need a trip to the dealer,but i'd try it first.The computer picks up the speeds etc. from the wheel speed sensors on each wheel,and about the only thing that messes them up,is if you switch to a taller or shorter tire from stock.