2012 5.3 gear ratio change ??

[n1020m]

I have a 2012 Avalanche LTZ with a 5.3L V8 and a 3.08 gear ratio.  It drives nice, but can't seem to get out of its own way.  Acceleration, especially while merging onto an Interstate is sluggish at best.  So, I have been thinking of changing the gear ratios to a 3.42 or higher.  Chevrolet only offered 3.08 and 3.42 in 2012.  I think there may be an aftermarket 3.73 available also.  I plan on keeping the vehicle a long time, so the expense now will have a good payoff for me.  I know the vehicle computer will have to be reprogrammed to match the higher ratio, but I am not sure if it can be reprogrammed for a non standard ratio.  Suppose I get 3.73 aftermarket gears and the computer reprogramming gives only two selections, 3.08 and 3.42, the standard ones for 2012.  Any ideas on this?  Will the 3.42 give me that much better acceleration?  Or, will the 3.73 be the way to go?  Just wondering!

 

[Randy]

There are a few threads about this that have a lot of answers... Same section you posted...




http://chevyavalanchefanclub.com/cafcna/index.php/topic,145441.0.html

 

[PromptCritical]

3.73 is pretty peppy off the line.  I'm going to miss it when I upsize the tires.

With the gears and the Diablo I'm getting nearly 16 mpg and I can chirp the tires at WOT going into second.

Edit: The Diablo allowed adjustment of ratio by .01 increments up to 3.73.  That's what I had so I didn't go higher, but I imagine it probably works the same out past 4.56.  I would not recommend higher than 3.73 unless you're going to drastically increase tire size.

 

[n1020m]

Thanks!  My tire size is P275/55 R20 from the factory!  So I think 3.42 might be the sweet spot for me.  Like I said, the problem I am trying to solve is slug slow acceleration.  Set up the way it is right now with my 3.08 it can only tow 5,000 pounds.  The 3.42 will bring that up to 5.500 pounds.  With a new radiator, it will be able to tow much higher loads, but for now, the acceleration is what needs fixed. I can always do the radiator later.  However, I may consider a 3.73, as my foot has always enjoyed a little lead in the sole. Thanks again for your input!

 

[shall36]

OP: did you get the gears swapped out? I'm planning a swap.

I was originally going to go with 3.42 but the shop I talked with made a good point when they said if you're going to do a gear change, might as well go more aggressive. So my plan is 3.73.  It's $1,000 for the swap and another $350 for the Diablo.

Even though I plan to tow heavy, I don't plan to swap radiators.  The heavy duty cooling does have a bigger radiator, but it's not that much bigger.  The fans are different, too, but that's really only a factor when stopped or slow. The heavy duty package does have an engine oil cooler in the driver side end tank, which would be nice, but if oil temp is a problem there are plenty of oil cooler options. The biggest deal seems to be the trans cooler, which I already installed a big tru-cool stack plate. The new Silverados with max tow use 3.73s. I wasn't overly impressed by it, but I'm sure they have it toned down.

 

[09chevyavy]

I swapped in 4.56 gears this past weekend on my 2009 with 6 speed. Too low for my 35s I have now but will have to deal with it until I get my 37s at the end of the month

 

[PromptCritical]

I swapped in 4.56 gears this past weekend on my 2009 with 6 speed. Too low for my 35s I have now but will have to deal with it until I get my 37s at the end of the month

How's acceleration?

 

[09chevyavy]

Runs like a bat out of hell haha. Its amazing

 

[SuperSports]

Did you change the gears?

 

[frito]

Did you change the gears?

Don't think he'll answer.  He hasn't logged in for almost four years.