2015 Silverado regear??

Silverado0925 · January 27, 2016

I know this topic has come up more then anyone wants but I'm new to this and didn't find much on the newer model silverado's. So I currently have a 2015 5.3l 4x4 Silverado and ordered (but not installed yet) the mcgaughy 7-9" SS lift kit with plans on setting it to 9" .. Fuel maverick rims and 37" tires. I also order a complete master ring and pinion 4.88 kit with a Yukon duragrip clutch type posi. Is this gear ratio a good setup for what I have and plan to do? Has anyone done a similar setup or know of anyone who has? I don't want my rpm's to be at 3000 at 65mph. A few say it won't be that high and others say it will. Does the tires make the only difference or does the lift also factor in when doing a regear? The shop I'm talking to said the lift doesn't make much of a difference (saying it does but not enough to notice) and tires is where the main factor comes in. I don't want to end up putting something in that's overkill ? I have a few other questions but I'll start with this and see if I can get any help or info. Thanks

07Softail · January 27, 2016

4.88's ,37's at 65 MPH at 1930 RPM's give or take a few rpms

RT

Silverado0925 · January 27, 2016

Thanks so much.. That's about where I am stock with 31.5" and 3.08 gears.. Have you ran the sane setup ?

Silverado0925 · January 27, 2016

Correction it's about 1400 rpm's at 65 stock

redwngr · January 27, 2016

OP didn't indicate which eng/trans, but rpm will depends a little on whether 6 speed or 8 speed (since the ratios are different).

Lift doesn't change gear ratio, so the shop is wrong that it makes 'a little' difference. If they told you that it does, I'd be looking for another shop for parts and advice.

Silverado0925 · January 27, 2016

It's an 5.3l automatic 6 speed ...

Txjose · January 28, 2016

I think 4.56s are better off for 37s

Sent from my Note 4 on Tapashit

royrjs · January 28, 2016

I'd even go with 4.10 if you'd like to have the same feel and get go with the current setup, here's my calculation according to my logic.

Current tire size (31.5) is to current gearing (3.08) like new tire size (37) is to new gearing.

NG = 37*3.08/31.5 = 3.61, which in reality rounds up to 3.73, as that's the gear ratio available for the 9.5 rear end (assuming that's the one you got on your truck).

Having the 3.73 as a result, I'd go one size ratio lower (4.10) to compensate for heavier tires; that's how I came up with the decision of going with 3.73 for my situation (35's) coming from the same stock setup you're coming. I haven't bought the parts, but I'll be doing so as soon as I get the moneyz.

Silverado0925 · January 28, 2016

I purchased fuel 37x13.50r24 and they are over 80lbs each .. With rims I'd say I'm looking at roughly 130lbs per rim and tire totaling 520lbs .. I know the lift is over 300 lbs as well and the gears for front and back with the duragrip arrived today and was 100lbs .. With my truck cover and other parts I'm easily over 1000lbs .. I also want the ability to tow if something comes up.. Figured 4.88 would be good but now I'm second guessing myself

royrjs · January 28, 2016

I considered the weight of the tires because it's unsprung and rolling weight; they are heavier to turn.

CAtaylor · January 28, 2016

4.88 minimum with 37's. 4.56 was perfect for much lighter 35's.

Kennith Pujol · February 23, 2016

I purchased fuel 37x13.50r24 and they are over 80lbs each .. With rims I'd say I'm looking at roughly 130lbs per rim and tire totaling 520lbs .. I know the lift is over 300 lbs as well and the gears for front and back with the duragrip arrived today and was 100lbs .. With my truck cover and other parts I'm easily over 1000lbs .. I also want the ability to tow if something comes up.. Figured 4.88 would be good but now I'm second guessing myself

Hey brother, did you ever get your wheels, tires, and gears installed? If so, how was the fit with the 37sx13.50 with the 9inch mcgaughys lift? How do you like the 4.88s and do you think you went too low for gears and should of did 4.56s? Thanks in advance man!

Silverado0925 · February 23, 2016

everything was done this week.. There is a little rubbing at full turns on the inner fender .. The gears all went in.. As far as gears go I would say 4.56 is plenty .. I'm fine with the 4.88 .. Rpm's are about 2250 at 70mph give or take.

Here is a list of what's done so far

7-9" mcgaughy lift set to 9" with rear add a leaf 1.5" ss kit

Custom grill and hood scoop painted to match

37x13.50r24 fuel mud tires

24x12 fuel maverick rims with center powder coated to match paint

Extang solid fold 2.0 cover

Dual exhaust

Complete regear from stock 3.08 to 4.88 front to back with duragrip posi track

Diablo t1000 tuner

N-fab chrome side steps

5% window tint all around

54" curved light bar arrived today and will be installed this week

Kennith Pujol · February 23, 2016

everything was done this week.. There is a little rubbing at full turns on the inner fender .. The gears all went in.. As far as gears go I would say 4.56 is plenty .. I'm fine with the 4.88 .. Rpm's are about 2250 at 70mph give or take.

Here is a list of what's done so far

7-9" mcgaughy lift set to 9" with rear add a leaf 1.5" ss kit

Custom grill and hood scoop painted to match

37x13.50r24 fuel mud tires

24x12 fuel maverick rims with center powder coated to match paint

Extang solid fold 2.0 cover

Dual exhaust

Complete regear from stock 3.08 to 4.88 front to back with duragrip posi track

Diablo t1000 tuner

N-fab chrome side steps

5% window tint all around

54" curved light bar arrived today and will be installed this week

Damn, that looks really good man. Makes me happy to see a new body truck with 37s and a re gear. Same exact rims I'm looking to run. Did they have to cut any of the bumper other then the plastic valance? In your honest opinion do you think the 4.88s is over kill for the 37s? How does the truck shift now compared to before with the 3.08s? Thanks again man. Truck looks good, keep it up!