Changing 3:21 to 3:92

[Narg]

I think I'd agree with those here that say to stay the course on what you have. I also got the 3.21 gears because I expected a lot of highway use. Then my wife came up with a "why don't we trailer camp?" thing after I got the new truck.

Mine is a LoAdEd truck. Seriously, lots of options, and that had an effect I didn't expect in that it made that truck super heavy. I have under 8K towing, and right at 1K of load. Kind of right on the money for a 1/2 ton by definition. Except for towing travel trailers, where many 1/2 tons are capable of much more. Even most ultralights will put this truck over its payload after me and my wife are in it. It's not the GVRW, but that tongue weight that is a killer. So, once we get to that time of trailering, I'll likely trade-in for a 3/4 ton. (My wife would never do a pop-up camper, it'd have to be more substantial...)

I expected the acceleration to be bad with the 3.21 when I got it, but it's really not. The saddest part of acceleration is the system lag in the peddle, which seems to be normal for many modern trucks. Once that Hemi realizes that I'm in the business of get-up-and-go, it's got plenty of power and speed to start from zero or to pass on the highway quite nicely.

 

[Narg]

Never heard this. Had mine on for 3 years worked great, I only took it off because I bought a Pulsar which gave me the same throttle response but with actual power addition.

Yeah, I'd never heard of it either when I bought mine. Google "peddle commander problems" though. It's an eye opener.

 

[Graygoose]

some I think have had Bluetooth issues, the one I have is hard wired, prefer that over the BT personally, never an issue, my 2015 Ram still has that one, and still driven daily.

 

[bchap05]

some I think have had Bluetooth issues, the one I have is hard wired, prefer that over the BT personally, never an issue, my 2015 Ram still has that one, and still driven daily.

Mine was wired as well, no issues ever

 

[MoPowered]

Unless you looking to invest 4K, and then some speedo recalibrating and atrocious gas mileage like single digits, just get yourself a pedal commander you’ll see a nice change in pedal response and performance. My 12 PW has 4:56’s stock but with the 37’s it take’s it down to 4.00’s somewhere and I still only get about 11 mpg.
But hey it is a Power Wagon.

 

[CheechDogg.0n37s]

My 14 RAM 1500 window sticker sai it had 355 gear ratio. But in truth it turned out it had 321. FCA had a good number of these happen. A class action was started by a Attorney and most went with him. Instead I dealt with FCA myself. The cost to change the gears was more than $2,500. FCA asked me what would it take to make me live with the truck? I asked FCA to change the gears as the window sticked stated. FCA offered to buy back the truck and me to pay 35 cents per mile for use. That was unacceptable for me. We came up with FCA putting on remote start and a folding truck bed cover. Retail sales for these items came to about $1,700. This was the best compromise that we settled on. Those who went with the attorney as I understand it got much less.

Changing gears is a huge task, and you might be better trading it in for what you really want.

My truck's window sticker said 3.92s, later I found out it was 3.21s which is BS! I ended up spending the $850 to regear which wasn't that bad I guess, but still I would love to get these fawkers for this bs ...

Good thing my truck is only a 2wd

 

[Pull Ya]

I know that Wild One has already chimed in once, but if you want really accurate information and a solid estimate of the cost you might PM him. He is kind of an expert on the swaps and I think he said he could do one in a couple of hours, in the driveway--maybe even one-handed--LOL. He has done plenty and has a lot of experience and can give you some great hands-on information.
Jay

 

[gfh77665]

This is the first I am hearing about the gearing numbers being incorrect. How can an owner find out if the gearing advertised on the sticker is wrong? How did you guys discover it?

 

[JoeCo]

This is the first I am hearing about the gearing numbers being incorrect. How can an owner find out if the gearing advertised on the sticker is wrong? How did you guys discover it?

The build sheet is more accurate than the window sticker (window sticker is almost always accurate but there have been some examples of incorrect window stickers as well). To get your build sheet, click on this link and enter your vin #:

https://fcacommunity.force.com/RAM/s/equipment-listing

If typing in your vin, make sure you use all capitals for the letters.

 

[crash68]

How can an owner find out if the gearing advertised on the sticker is correct? How did you guys discover it?

Check your rpm at 70 mph in 8th gear
For a truck with 20"s(33" tires):
3.21 gearing 1550 rpms
3.55 gearing 1700 rpms(V-6 engines)
3.92 gearing 1850 rpms
If the truck has 17"s(31.5" tires) the above rpms will be about 100 rpm more

 

[gfh77665]

That's great info guys. Thank you both!

 

[Sherman Bird]

Is it a big job to change my 2018 Express 3:21 to 3:92's? I'm guessing it's not just pulling out and swapping the gears and axles? And yes I did a search and couldn't come up with anything.

I once was married to a very progressive wife in terms of car stuff and humor. I remember kidding her about her "positrac" rear end one time..... she burned dinner.

 

[Sherman Bird]

Is it a big job to change my 2018 Express 3:21 to 3:92's? I'm guessing it's not just pulling out and swapping the gears and axles? And yes I did a search and couldn't come up with anything.

I would think the PCM would have to be configured for such a big gear ratio change.

 

[Ohio5pt7]

I would think the PCM would have to be configured for such a big gear ratio change.

You would have to flash the pcm for any gear change or tire size change if you want the speedo to be accurate.

Sent from my SAMSUNG-SM-G891A using Tapatalk all grammar errors brought you by fat fingers and auto correct.

 

[crash68]

You would have to flash the pcm for any gear change or tire size change if you want the speedo to be accurate.

If your just changing gears the speedometer will still read correctly as the truck uses the ABS wheel speed sensors for the speedometer. The ECM/TCM should be updated with the correct gear ratio for any shifting or control logic.
I know with the EcoDiesel that if the ECM doesn't have the correct gear ratio that there can be issues with the cruise working.

 

[Sherman Bird]

You would have to flash the pcm for any gear change or tire size change if you want the speedo to be accurate.

Sent from my SAMSUNG-SM-G891A using Tapatalk all grammar errors brought you by fat fingers and auto correct.

Actually the speedo is only one factor. The proper function of the torque converter lock up clutch is greatly affected by changes to tire size or gear ratio changes. These newer modern torque converters are controlled by "fuzzy logic" programming. This is a controlled slip that is within a very narrow window of operation to allow slippage without burning the converter up. The point of this is to provide smooth converter clutch operation. You older geezers such as me remember the days that converter clutch lock up felt like a firm shift... and was very annoying when one would dirve in traffic at about 45 MPH under light throttle and the converter clutch would hunt. People used to have me disconnect TCC on older transmissions where there was no risk of damage to the transmission. That's no longer possible to do on new vehicles... and in many cases, one will destroy the trans over a long term if these changes to tire size or gear ratios are done without calibration.

 

[Sherman Bird]

I estimated upwards of $1700 just to change my 3:55 std. rear to a limited slip.
No ratio change so nothing to change up front, just swapping the rear chunk for a posi and the labor.
Just to have two stripes on burnouts? Not worth it.

Food for thought...

It's worth it if you want to maintain control on slippery surfaces... but today's Vehicle Stability Control kind of trumps the necessity for posi-trac. I'd postulate that posi would still play a good part in maintaining traction.

 

[crackerjack1957]

Gear ratio change is actually in the BCM......HPtuners will change Dodge/Ford without having to buy license.

 

[Sherman Bird]

Gear ratio change is actually in the BCM......HPtuners will change Dodge/Ford without having to buy license.

Yes, I can do the changes using my MS906BT Autel. These scanners have really gotten much better about including software for coding and other changes and key programming. I recently repaired a flood damaged 2017 Hyundai Accent and had to replace the SRS (airbag) module, the passenger seat weight wensor and it's converter. These had to be coded and calibrated to turn off the air bag light.... and center the steering angle sensor. Life is good!