Bigger tires and sloppy transmission shifts

[Iron Outlaw]

So I leveled my truck and got 35 inch tires. I've noticed that my 6th to 5th downshift feels like it slips a little and is harsh. It's bad enough that I hardly run 6th gear now. I only really need it when running 75+ on the interstate as I have 373s. I would like to regear but wonder if this is a tuning issue since I havent tuned it yet for the bigger tires, or is it transmission issues coming to light.


Anyone else with similar experience? I want to do .488 gears but they have to wait for me to save the extra cash. The truck seems to do fine driving normal speeds 1st-5th.

 

[AFMoulton]

So I leveled my truck and got 35 inch tires. I've noticed that my 6th to 5th downshift feels like it slips a little and is harsh. It's bad enough that I hardly run 6th gear now. I only really need it when running 75+ on the interstate as I have 373s. I would like to regear but wonder if this is a tuning issue since I havent tuned it yet for the bigger tires, or is it transmission issues coming to light.


Anyone else with similar experience? I want to do .488 gears but they have to wait for me to save the extra cash. The truck seems to do fine driving normal speeds 1st-5th.

UnHook your battery and leave it off for 24 hrs. That’s will clear the logic in the trans module. Then drive it normal and the shift points will adjust to the new tires.


2018 2500 6.4 4x4 4.10 Amsoil SS 0w-40, Softopper
Black Rhino Armory 18x9 +12mm
Cooper St MAXX LT295/70R18

2016 Durango 5.7 AWD 3.07 Redline 5W-30 RP 10-48
1996 Nissan Altima 2.4 Amsoil SS 5W-30

 

[SouthTexan]

I agree with AFMoulton. Put your trans into relearn mode and take it easy(under 30% throttle) trying to go through all of the gears as much as possible in stop and go driving for the about 30 miles or so. This should be enough drive time to relearn the clutch packs and shift strategies.

 

[Jimmy07]

Disconnecting the batteries will not “reset the logic” for the transmission. This can only be done by performing the quick relearn procedure with a capable scan tool. If you correct the speed for the bigger tires, it will shift like it did before.

 

[olyelr]

Definitely get something to change your shift points back to normal now that you have larger tires. I used the Tazer RAM. Made a world of difference. But it doesn't hide the fact that it still needs a regear.

 

[AFMoulton]

Weird, the battery truck worked for my ‘18 2500. Although it does not change the need for a re-gear! Which will need a programmer or AlphaOBD


2018 2500 6.4 4x4 4.10 Amsoil SS 0w-40, Softopper
Black Rhino Armory 18x9 +12mm
Cooper St MAXX LT295/70R18

2016 Durango 5.7 AWD 3.07 Redline 5W-30 RP 10-48
1996 Nissan Altima 2.4 Amsoil SS 5W-30

 

[Iron Outlaw]

Guess I need to order a tuner of some sort. I'm not sure the taser will work for me because my gauge cluster doesnt show the radio stations. I'm looking at the edge pulsar now. Not too bad expensive and it is supposed to add a noticable amount of power.

 

[Jimmy07]

Guess I need to order a tuner of some sort. I'm not sure the taser will work for me because my gauge cluster doesnt show the radio stations. I'm looking at the edge pulsar now. Not too bad expensive and it is supposed to add a noticable amount of power.

Just get the AlfaOBD. It’s cheaper and FAR more versatile than the one trick pony programmers. https://www.ramforum.com/threads/alfaobd.123982/
Edit: never mind. I see that you actually want to tune also.

 

[mtofell]

But it doesn't hide the fact that it still needs a regear.

^^I agree with this.... stock tires and 3.73 gears is borderline ridiculous, especially paired with the "challenged" 66rfe tranny. Bigger tires are only going to make a bad situation worse.

The good news is I think you'll be super happy with new gears. From doing a lot of reading on here I think 4.56 would be perfect with the stock tires. Maybe a bit taller if you run bigger tires. I suppose it also depends how and where you drive your truck. Where I live, traffic rarely moves faster than 30. If I were in Texas and the speed limit was 80 I might have a different opinion.

 

[Bigseff23]

I did a level and 35's and didn't have a problem.