dubless

Hi Guys,
In the next few weeks I'm going to be lifting my 15' 2500 4.8L van and putting on a set of 33" tires.
I'm also planning on regearing to a GM 4.10 gearset to compensate for the larger tires.

If anyone has any experience regearing their van, do you need to reprogram the ECM for the correct gears, tires, speedo etc.
If so, do you have any recommendations? I can't seem to find one that specifies an application for the Express van.
Also any issues with the Stabilitrak after reagearing?

Thanks!

mountainmanjoe

what is your original tire size? Calculate the RPM change from tire size.

what is your original axle gear ratio? Calculate the RPM change from gear ratio.

One will offset the other, and you might be fine. But if the the final RPM change is too far from the original, then it will negatively affect the traction control system, the stabilitrak, ABS, the speedo, odo, and transmission shifting. In that case, yes the PCM would have to be reprogrammed by a shop that owns the equipment capable of it. 33" diameter tires were never a factory option though (and I don't think I've seen 4.10 gears on a 2015), so it would have to allow some kind of custom calibration.

How are you lifting the rear?

dubless

My differential guy tried to decode my VIN / Build code sticker to determine my axle ratio but for some reason it comes back NA. He believes it's most likely 3.42 but won't know for sure until he opens it up. In terms of gearsets, he did check and find there is a factory GM 4.11 R&P that fits my application.

Still on the fence though as it's a pretty big jump going from 3.42 to 4.11 especially since my original tire is a 30.5" 245/75/16 to a 32.6" 285/75/16. He recommended 3.73 for mpg and 4.11 if I plan to do any heaving towing. I'm not planning on towing anything large anytime soon but would be good to know my axle ratio would be up to task if I decide to. He also wasn't entirely sure if I'd need to reprogram the ECU or not since he hasn't done any gear upgrades on an Express van. He did mention that Silverados definitely need to be programmed as like you mentioned it effected their abs and stabilitrak triggering.

Looks like I need to study these online calculators a bit more to see where my RPM's will be.

tech2

my 2500 pu had the 4.10's. I've driven 3.73 and 4.10 and the 4.10 is way better...truck has *****

dubless

Awesome! Did you have to reprogram your ecu for the new gears? What year is your PU?

tech2

I didn't swap. you will have to change the programing for the transmission

Andres david

hi brother how was your

mountainmanjoe

tire size calibration