Re-gear for 33" tires - What Ratio would you choose?

Kerrslight · December 15, 2015

I've read through just about every gearing thread on here and I'm still up in the air. I think my mind is trying to find a direct answer to what ratio most would go with or have experience with when going to a 33" tire, but in the end it is all personal opinion. That being said, I will throw out my dilemma.

I currently have the 3.08 ratio and after the first of the year I will be picking up some 33" Toyo MT's. Some say the 3.08 is fine with larger tires and others disagree. From my experience on stock tires and the occasional towing, I hate the 3.08. I do like the mileage I am getting, but it's not the biggest factor in the world if it decreases with larger tires and a gear swap. I don't tow all that often, but when I do is usually a fourwheeler/dirt bikes, jetskis, and occasionally my 26' boat. I don't want 4.56 as that's more than I need, but I'm stuck between 3.73 and 4.10. My guess is in the end I'd probably go the 4.10, but want some feedback as to what you guys would do.

If replaced with 4.10, any idea what RPM's would be like cruising down the highway?

KMGZ400 · December 15, 2015

I would see how it drives with the 3.08s first, a 33 is barley taller then a stock 265. But if you do swap, definitely 4.10s, 4.56 is a little aggressive for a stock height truck on 33's

Kerrslight · December 15, 2015

I would see how it drives with the 3.08s first, a 33 is barley taller then a stock 265. But if you do swap, definitely 4.10s, 4.56 is a little aggressive for a stock height truck on 33's

Yea it's not the size I'm worried about. I have a tuner than I can correct the speedo with. I'm looking more at the added weight. 72lbs/tire. I just don't want to be handicapped when it comes to towing because I've got larger/heavier tires.

Thanks for your input.

KMGZ400 · December 15, 2015

If you plan on keeping the truck for a while if go for the regear.. Towing with the 3.08s is pretty brutal on even stock tires

Kerrslight · December 15, 2015

Yea it is. I hate it. Even just putting my dirtbike and gear in the bed I can tell a difference in the way it drives. Pretty pathetic.

07Softail · December 15, 2015

4.10 would be my pick.

RT

Txjose · December 15, 2015

Im re gearing to 4.10s from 308s and have 33x12.50x20s.... Truck hunts for gears as is i can imagine towing. I havent pulled anything with it yet but i plan on going to 35s later on and hooking up an RV.

How it is right now i think my 2005 5cyl colorado crew cab can out tow my 2014 silverado 5.3 lol

07Softail · December 15, 2015

With 4.10's and 33's Running 70 MPH the Tach will read 1958RPM. With 4.56 RPMs will be 2178 so you get the idea.

RT

Kerrslight · December 16, 2015

Thanks guys. Very helpful.

Im re gearing to 4.10s from 308s and have 33x12.50x20s.... Truck hunts for gears as is i can imagine towing. I havent pulled anything with it yet but i plan on going to 35s later on and hooking up an RV.

How it is right now i think my 2005 5cyl colorado crew cab can out tow my 2014 silverado 5.3 lol

Do you have a tune or anything on your truck now? I've got diablew tune so I'm hopeful that will minimize the gear hunting a little bit at least until I do the fear swap.

Txjose · December 16, 2015

Thanks guys. Very helpful.

Do you have a tune or anything on your truck now? I've got diablew tune so I'm hopeful that will minimize the gear hunting a little bit at least until I do the fear swap.

Not yet. All i have is an Airaid CAI.i have acess back home to very talented tuners that have LS world records in trucks ao im in good hands when i get home. Unfortunately i will not be able to compare just the tune its self as the truck is going in for the full treatment of head work, ARH headers, 4.10s all around, custom exhaust.... And if all goes well a whipple

sailor9908 · December 16, 2015

Not yet. All i have is an Airaid CAI.i have acess back home to very talented tuners that have LS world records in trucks ao im in good hands when i get home. Unfortunately i will not be able to compare just the tune its self as the truck is going in for the full treatment of head work, ARH headers, 4.10s all around, custom exhaust.... And if all goes well a whipple

I've currently got 3.43's in mine with 6.5" of lift and 35" tires. The blower, headers and tune help and have given me essentially a brand new truck but I still plan on going with 4.10's or 4.56's when they make some for the new rear diff's and it doesn't cost an arm and a leg for them.

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Maine-iac · December 16, 2015

Why is it they would put this gear in a truck? It seems to me to have almost no use, even as a strict driving truck. I have heard nothing good about the gears in all truthfulness. Has this(the use of 3.08) occurred in the past? I don't know anything about it besides the complaints. WHY did GM put it in their trucks?

robvas · December 16, 2015

Why is it they would put this gear in a truck? It seems to me to have almost no use, even as a strict driving truck. I have heard nothing good about the gears in all truthfulness. Has this(the use of 3.08) occurred in the past? I don't know anything about it besides the complaints. WHY did GM put it in their trucks?

Because it's still better than the old 3.42/4-speed combo. Heck its about equal to a 4.10/4-speed combo , with an extra gear to boot!

That chart is how many times the engine must turn to make the rear wheels turn one time in a given gear with a given gear ratio. The higher the #, the better.

Georgia1911 · December 16, 2015

I've currently got 3.43's in mine with 6.5" of lift and 35" tires. The blower, headers and tune help and have given me essentially a brand new truck but I still plan on going with 4.10's or 4.56's when they make some for the new rear diff's and it doesn't cost an arm and a leg for them.

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I believe AAM offers a 4.10 gear set that will fit a new 9.5" 12 bolt. Same carrier as the 3.42, but would need to change if you had a 3.08.

Georgia1911 · December 16, 2015

Because it's still better than the old 3.42/4-speed combo. Heck its about equal to a 4.10/4-speed combo , with an extra gear to boot!

That chart is how many times the engine must turn to make the rear wheels turn one time in a given gear with a given gear ratio. The higher the #, the better.

Yeah, I read all these threads on regearing where it seems we are stuck in the '70s. With the 6L80 and especially the 8L90, we pick up lower gears that put the overall ratio right where it should be with a higher (lower numerically) ring and pinion. Nothing wrong with a taller overall gear for highway use with light loads if we still have the short ratio to get out of the hole when loaded.