Gear swap Do I need computer reflash?

[swathdiver]

Bruce, I think you're information is correct, I've seen nowhere to make such a change. The wheel speed sensors probably tell the speedo what to do and the transmission measures engine rpm, input shaft speed, output shaft speed and even slippage. There's no place to even see an axle ratio. The transmission and transfer case modules do show their gear ratios but no final drive ratios. I think you're good to go.

Nate, do you know what our final drive ratio is in 1st gear for a 6L80E? It's 13.77:1. A fella with a 4L65E and a 3.42 will see 10.46:1 and with a 3.73 gear will see 11.41:1, about the same as a Duramax in front of an Allison with 3.73s.

If he's near max weight in tow/haul mode he'll just have to slow down some to keep the motor in the sweet spot if he doesn't want to run the 3.73s. What was it, 2200-2300 rpms?

 

[Scottydoggs]

im still new to hp tuners, but we got this gear tire wizard.

 

[kbuskill]

ABS sensors or not.... your Speedo will not be accurate. There is a reason why we have the option to calibrate the Speedo with a Diablo.

When you get in the mountains you will wish you had 4:11s.... lol

 

[Doubeleive]

Hello I have a question. I've searched the forum and I didn't see anything on it. I havea 2012 Tahoe 5.3 with 3.08 gear ratio. I haul a 2017 Forest River wolf pup and a 16 foot enclosed with toys. I'm wanting to go to 3.42 gear ratio because I live in West kentucky. And I'm taking family to Yellowstone for the first time in June. Besides the normal ring and pinion labor. What has to be done to computer. Also since I can't find any definte answers what the heck is the tow rating for this stupid thing. I've read 5k with 3.08 then 3.42 is 7000 to 8600 with or without a trans cooler. Thanks

Yellowstone is awesome, just go prepared even in nice summery July weather can turn on a dime. and---bring whatever supplies you think you might need there isn't much of anything near or in the park

 

[jrstroh]

Thanks guys. Now to find the ring and pinion I want and make sure my tuner will do the job just in case the computer doesn't play nice. If it wasn't for using this thing to make money I would have my duramax I want. But until I can finish college and find a job that'll hire a broke dick infantryman. I'm stuck with Uber. So I think 3.42 will help a little all around and not kill my gas mileage. From Kentucky to penscola beach and back I averaged 8.8 mpg with camper, enclosed I get 14 mpg and summer in Nashville hauling customers around I get 16.8 then highway depending on terrain and my goot 18-22 mpg. I have to tear her apart tomorrow because I'm hearing and feeling something again. i hope it's not my hub assemblies again. If it is I'm glad I bought lifetime warranty one's. Plus it's time to rotate tires and change oil. Well see if I can cheat on gear ratio swap. If I can find a axle cheap enough I may swap the complete assembly. But we'll see. Thanks again

 

[jrstroh]

Yellowstone is awesome, just go prepared even in nice summery July weather can turn on a dime. and---bring whatever supplies you think you might need there isn't much of anything near or in the park

We're hitting Yellowstone May 29-June 7th. So we'll be chilly

 

[HiHoeSilver]

Bruce, I think you're information is correct, I've seen nowhere to make such a change. The wheel speed sensors probably tell the speedo what to do and the transmission measures engine rpm, input shaft speed, output shaft speed and even slippage. There's no place to even see an axle ratio. The transmission and transfer case modules do show their gear ratios but no final drive ratios. I think you're good to go.

Nate, do you know what our final drive ratio is in 1st gear for a 6L80E? It's 13.77:1. A fella with a 4L65E and a 3.42 will see 10.46:1 and with a 3.73 gear will see 11.41:1, about the same as a Duramax in front of an Allison with 3.73s.

If he's near max weight in tow/haul mode he'll just have to slow down some to keep the motor in the sweet spot if he doesn't want to run the 3.73s. What was it, 2200-2300 rpms?

I'm on a 4l60 with 3.42. My mileage seems to have fallen off a little since we last talked about it. I'm not sure if it's just from warming it up all the time or if there's more to it. Tune up plart are in the garage. I can only see avg. There is no real time reading in NBS.
No question my milage is better than when i had 3.73, but getting her moving is noticeably different. If I was towing near capacity, I'd trade back in no time.

 

[jrstroh]

I had a 04 Silverado Z71 with 3.73, 5.3 and the 4l60e. Cold air intake with Flowmaster. But this tahoe seems to to take off harder that it did and its a ton load faster than the silverado. I know it has a few horsepower more factory and the Tahoe seems to weight more. It kind of makes me wonder if the previous over changed gearing. I haven't pulled it apart yet so I don't know.

 

[swathdiver]

Check CL. There was a guy selling the ring and pinion for the longest time but I don't see it now. I do however see a guy selling the whole rear axle for $300 in my neck of the woods. Check yours.

 

[jrstroh]

Check CL. There was a guy selling the ring and pinion for the longest time but I don't see it now. I do however see a guy selling the whole rear axle for $300 in my neck of the woods. Check yours.

I will do. I just got do changing oil, spark plugs, wires and rotating tire. I found my right rear axle seal is leaking not bad but I can smell the gear lube or baby crap. Then I found one of the plastic clips and o ring is leaking for rear heater core. Right above number 8 cylinder. Not bad but enough to catch my attention. Fun fun