does anyone here have a gear ratio of 3:55 and runnin on 33s

[johnnydee3]

wont 4:11s be to hard on the engine when your on the highway?

 

[FROADER]

wont 4:11s be to hard on the engine when your on the highway?

It will be close to the stock ratio, so no

 

[johnnydee3]

can you get gears installed at any shop tho..or does it have to be a gear shop?

 

[FROADER]

Depends on the shop. Most can do it, but just call the local shops and ask. Compare prices and choose that way.

 

[johnnydee3]

are 4:10 and 4:11 the same thing

 

[FROADER]

For the 8.8 rear end you have, you'll be getting 4.10, but yes pretty much.

 

[DeRocha]

wont 4:11s be to hard on the engine when your on the highway?

Not at all... 4.10s with 33s will be the same as running 3.55s with stock tires (235/75R15). Follow the link in my sig line for axle gear calculators..
Find new Gear Ratio with new tire size
If you input new tire size 33, old tire size 28.5
You'll get a gearing value of 4.11
this value will give you the same performance you currently have (maybe slightly more power depending on the actual tire diameters involved since not all tires are exact measurements from manufacturer to manuafacturer.

In a nutshell if you're running 33s tires and regear to 4.10s it'll feel the same as running stock tires with your stock 3.55 gearing.. If you regear to 4.56s you feel a noticeable increase in power. The trade off or balance is power vs economy when running highway speeds. Again plug in the numbers in the RPM section and you'll see that with 33s and 4.10s you'll be running 2,035 at 65mph.. with 4.56s you'll be @ 2,263 rpm.

 

[johnnydee3]

Not at all... 4.10s with 33s will be the same as running 3.55s with stock tires (235/75R15). Follow the link in my sig line for axle gear calculators..
Find new Gear Ratio with new tire size
If you input new tire size 33, old tire size 28.5
You'll get a gearing value of 4.11
this value will give you the same performance you currently have (maybe slightly more power depending on the actual tire diameters involved since not all tires are exact measurements from manufacturer to manuafacturer.

In a nutshell if you're running 33s tires and regear to 4.10s it'll feel the same as running stock tires with your stock 3.55 gearing.. If you regear to 4.56s you feel a noticeable increase in power. The trade off or balance is power vs economy when running highway speeds. Again plug in the numbers in the RPM section and you'll see that with 33s and 4.10s you'll be running 2,035 at 65mph.. with 4.56s you'll be @ 2,263 rpm.

um...is says that 33s and 4.10s will run at 2713at 65 mph...when really at 2713 with 4.10s youd be goin 48 MPH.

 

[JDraper]

um...is says that 33s and 4.10s will run at 2713at 65 mph...when really at 2713 with 4.10s youd be goin 48 MPH.

Nope...you're putting something into the calculator wrong. I'm on 33's with 4.56's and I know I'm turning under 3k at 65mph.

 

[johnnydee3]

no im not...i double checked like five times...do it for yourself
http://www.4lo.com/4LoCalc.htm

 

[JDraper]

MPH:65
Axle Ratio: 4.10
Transmission Ratio: .75 (overdrive)
Transfer case Ratio:1 (in 2wd or 4 Hi)
Tire Diameter: 33

Answer from the Calculator is 2035.090

I drive my truck daily on 33's with 4.56's. I have corrected the gear in the speedometer to offset the change in tire/axle ratios. At 60 mph, I'm turning just about 2100 rpm's which matches up nicely with the calculator.

 

[johnnydee3]

what about with it not in overdrive

 

[JDraper]

what about with it not in overdrive

The calculator spits out 2713.454 rpms at 65 mph with 33's and 4.10 gears.

 

[johnnydee3]

with it not in over drive the transfer case is 1 right?

 

[JDraper]

Transfer case in 2WD or 4WD hi is a 1:1 ratio. For no overdrive, you plug in 65 mph, 1 for the transmission ratio, 1 for the transfer case ratio, 4.10 for the gear ratio, 33 for the tire size, and it spits out the 2713 number.

 

[johnnydee3]

ok...i think i am just goin to install a tranny cooler and shift kit and avoid doin gears

what do you think?

 

[JDraper]

See post #15 in this thread.


A cooler will help increase the transmission life, but it will still be a dog on the highway. There is no cheap way to get around it. IF you want the truck to perform decently on 33's with your stock 4.0 motor, you need to regear..period.

 

[johnnydee3]

the shift kit will help to...and by the way...i dont really care that i wont be able to go screamin by ppl anyways..id prolly get better gas mileage cruisin at 65 and 1600 rpms

 

[JDraper]

the shift kit will help to...and by the way...i dont really care that i wont be able to go screamin by ppl anyways..id prolly get better gas mileage cruisin at 65 and 1600 rpms

Actually, you won't get better mileage. You'll get worse because the truck will be laboring hard to hold speed with all the rotating mass and low ratios. Trust me, I've been doing this kind of stuff for almost 30 years...

The shift kit might help the tranny life some, but it won't help on mileage or acceleration much. You can set the shift points higher with most shift kits, which will help a little, but with that size tire and 3.55's, you're going to be on the floor a lot anyways, so a delayed shift won't be noticed much.

I ran my truck on 3.27 gears and 33's for about a week before I got my 4.56's, and it was horrible. Gas mileage was around 10 mpg and the tranny shifted constantly. Put the 4.56 gears in and went back up to about 15-16 mpg and the transmission is much happier.

 

[johnnydee3]

hwo is it happier when ur spinning under 3k rpms goin 65 mph