I’m going nuts with 3.21s and 35” tires

[Dragon62]

I have 3.21s with 35s on 22 inch stocks and have zero issues. maybe the wheel you are using is extremely heavy?? But these trucks can easy handle 35s or 33s. Now if you are trying to haul *** everywhere on 35s vs stock tires/lighter, that's diffrent, they truck will respond to how how u treat it

Hi, I know this is an older post but hoping you catch this... I just picked up my '21 bighorn and sound like you might have some input. I have had several GM's and this is my first Ram. Finding myself in unfamiliar waters, these trucks are setup different. I have the 3.21 rear and want to put on 35" Nittos on 20" rims. How are you getting along with the 3.21 and your 35's? Still good with the over all ride and no issue thoughts? I stay on flat grounds and some fire trails, mixed city/ hwy driving.. Thanks.

 

[Dragon62]

My 19 is my second ram with 321s and 35s. I don't really notice any difference between stock and the 35s with custom wheels and lift.

Still liking the 3.21 and the 35" ride and fuel setup? Any special programming done other then speedo? I'm looking at putting 35" on my new ride. Thanks.

 

[Troyoffroad]

I just installed a set of 295/70 R18 Falken Wildpeak at3w tires (actual size 34”) and Fuel Shok wheels 2 days ago on my 2019 Ram 1509 Laramie with 3.21’s. I also installed a Motofab 2.5 leveling kit. Took my 1st 3 hour road trip yesterday. It drives awesome but definitely was hunting between 7th and 8th gear trying to maintain 70-80mph speed. I averaged 21 mpg on highway trips with my stock tires but only got 14mpg yesterday. Definitely going to regear to 4.10’s soon if possible. Also installed the Banks Pedal Monster which made a huge difference in overall drivability around town. Definitely recommend the Banks

 

[Mountain Whiskey]

Good luck getting different gears installed. It's not a Jeep.

Yea, plenty of guys on the thread for 3:21 vs 3:92 going back and forth. Most defending their mistake of getting an anemic gear ratio that does not really give room for upgrades or modifications, swearing they get great gas milage. Others just pointing out the obvious mistake of 3:21s.

 

[Pertzbro]

Anything over 70mph you're dealing with a massive amount of extra wind drag on the truck being higher off the ground and larger width tires.

 

[KWKSLVR]

I mean, it's simple. If you want fuel economy with 3.21 gears stick with OEM specs. This tends to be true with everything. If you want to ride around with a gaudy looking redneck truck getting 10mpg riding slow as sin, get 3.92 gears. To each their own, just know what you're buying before you buy it.

 

[Drivinfast247]

I mean, it's simple. If you want fuel economy with 3.21 gears stick with OEM specs. This tends to be true with everything. If you want to ride around with a gaudy looking redneck truck getting 10mpg riding slow as sin, get 3.92 gears. To each their own, just know what you're buying before you buy it.

Quite sure you don't know how gear ratios work. Lol

Sent from my SM-G998U using Tapatalk

 

[KWKSLVR]

J-O-K-E

Kinda like the endless gear ratio conversations here.

 

[Mountain Whiskey]

I can't believe the gear argument thread has died down with less than 1000 usless posts. It was a great thread for stirring the poop!

 

[Maxum]

I knew when I installed the 35s I would lose some cruise rpm and effective gearing but I really did not expect the truck to be hunting between 7-8th gears on flat ground. This is killing me. I am aware I can just get some shorter tires but the current stance I have is important to me. I asked my dealer to price out a loaded 3.92 new rear housing and front section but they arent even sure it is available and if so what the cost will be. This crazy there is no aftermarket support for these axles.
I think my best bet here is to either find someone to switch and pay for the labor, or trade in on a different truck. But my truck is a good one so i hate to roll that dice. For now i have to keep hitting the steering wheel gear limit button and lock out 8th gear.
I made a big mistake.

I have 33" with 3.92 and even that is noticeable, so 35's on 3.21 is cring worthy for sure! You can get 33" in a P rated, which are about 10lbs lighter per tire in some cases, so that might be your cheapest and best option. 35's are all LT as far as I know. The weight is as much an issue as the diameter, maybe more.

 

[DJ menace]

I recently installed a 3.5 readylift leveling kit and have been shopping for tires. However, I recently noticed that people experienced shifting issues after installing 35s with 3.21 gear ratio. I didn't even know this was an issue. Is this still a problem currently? I have a 2022 ram 1500, 4x4 crew cab big horn...

 

[Mountain Whiskey]

I recently installed a 3.5 readylift leveling kit and have been shopping for tires. However, I recently noticed that people experienced shifting issues after installing 35s with 3.21 gear ratio. I didn't even know this was an issue. Is this still a problem currently? I have a 2022 ram 1500, 4x4 crew cab big horn...

Yes, it is an issue. Nothing has changed. You are getting ready to put the truck up at the height it should come from the factory with adding wind resistance. Then you plan to add heavier, larger diameter tires like it should have come with, more resistance. Unless you are stretching rubber bands over wagon wheels like some guys do. This all adds up to the need for torque to keep rolling. It is not a matter of rpm, or towing capacity. You just want gears to move the giant hunk of steel efficiently. Drivetrain torque. 3.92 torque.

 

[6of36]

Yes, it is an issue. Nothing has changed. You are getting ready to put the truck up at the height it should come from the factory with adding wind resistance. Then you plan to add heavier, larger diameter tires like it should have come with, more resistance. Unless you are stretching rubber bands over wagon wheels like some guys do. This all adds up to the need for torque to keep rolling. It is not a matter of rpm, or towing capacity. You just want gears to move the giant hunk of steel efficiently. Drivetrain torque. 3.92 torque.

I finally agree with you. When people make all sorts of modifications, they could need a 3.92.

 

[Mountain Whiskey]

I finally agree with you. When people make all sorts of modifications, they could need a 3.92.

Haha! We can go back to the gear ratio grand royal thread and throw dirt!

 

[RVTRKN]

I don't like the 3:21 ratio, however I've found to have plenty of power, even towing my light Tritoon (est 5K lbs). I didn't buy new so I found something as close as I could get to what I needed, seeing how I downgraded from a 2019 3500 SRW HO, (What a nice truck) I hadn't really studied the 1500's. I did find that every truck I looked at, did not have the 3:92 option. I'll be driving the 2020 1500 3K + miles, and the 3:21 will payoff for sure on the trip.

I don't understand why owners change so much from stock form, that they run into issues like the OP.

 

[JerryBsizzle]

35x12.50s and 3.21s and I have zero issues. Can do 77-78mph in 8th at about 1700 rpm. This is my 2nd 5th gen with a 6" lift and 35s, and on the first one I didn't recalibrate the speedo right away and it hunted for gears (of course). Speedo cal with the actual measured height, not listed height from a website, fixes it.

 

[RVTRKN]

That would make since, if the computer takes into account the different parameters of new values, that your truck is different than the OP. Is it the TCM or the ECM that changed inputs ?

 

[DJ menace]

35x12.50s and 3.21s and I have zero issues. Can do 77-78mph in 8th at about 1700 rpm. This is my 2nd 5th gen with a 6" lift and 35s, and on the first one I didn't recalibrate the speedo right away and it hunted for gears (of course). Speedo cal with the actual measured height, not listed height from a website, fixes it.

So just recalibrating the speedo to the correct tire height fixes the shifting issues?

 

[JerryBsizzle]

So just recalibrating the speedo to the correct tire height fixes the shifting issues?

It did for me. I'm on my second 5th Gen with 6" lift and 35x12.50s with 3.21s. No issues. Would do it again.

 

[DJ menace]

It did for me. I'm on my second 5th Gen with 6" lift and 35x12.50s with 3.21s. No issues. Would do it again.

I used alfaobd to recalibrate my speedometer after upgrading my tires to 295/60r20. Only time will tell if updating the tire size on my BCM alone will work. If not, I'm going to buy rough country's speed recalibration tool. It apparently not only calibrates the speedometer but adjusts the ECM to modify the shift point base on the tire sze.