I am considering changing from 3:31 gears to 4:10 gears. I am pulling a 5,000 lb camper and the 3:11 gears just don't cut it. I have a 95 F-150, 302, 4x4. Will I notice a considerable increase in torque? I am running P265/75R/15 tires.
Also, I don't see many axles codes that list the 3:31 gears. Are these gears for economy? Thanks in advance

 

4.10 gears are excellent for towing. A change of .5 or more will provide excellent results. You will have plenty of top speed with 4.10s. 3.31 are not as quick or capable for towing and are more oriented for highway driving and all around. I hope this helps some.

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2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification,Superchip,
Dynomax ultra-flow welded 3" cat-back.

 

Go with 4.10's, you probably don't need that low, but you'll be WAY happier. You'll lose a little mileage, maybe 1-2mpgs? you can gain that back with some mods. higher gears(3.31) are made for commuting, like max mentioned. The have too low, low end torque but have more high end than lower gears(4.10). 3.31 gears, means that the engine is rotating 3.31 tires, where the 4.10's are rotating 4.10 times. I think that means for ever complete spin of the wheel. Plus if you ever decide to go with a lift and/or larger tires, it won't hurt acceleration so bad. The larger the tire, the higher the gear ratio will actually be turning. for example, if you had 235's you would actually be spinning at 3.31 times, but you have 265's so you probably are spinning at maybe 3.00 instead. does this jargon make since??

 

One complete tire revolution = 3.31/4.10 driveshaft revolutions.

-Pastmaster: your jargon makes good sense.
235/265 is tire tread width only. As not to confuse 1ToughTruck, lets say tire height can change your effective ratio. The 235/265 scenario only applies when aspect ratio is included.

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2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification,Superchip,
Dynomax ultra-flow welded 3" cat-back.

 

Max: Isn't 265's actual height about 31"?
I know that 235's height is almost 29".
I think 285's height is about 33".

I'm not used to these styles of sizes of tires. I know the 31's and 33's and etc. Even though they don't actually add up to their titles.

 

Are you locking out OD when you tow? I have the 3.31s in my truck. They're great on gas on the road, but when the truck had no mods it had a hard time staying in OD with a heavy load. I just do the heavy stuff in 3rd, the revs are still fine. Keep in mind that once you go to the 4.10s your highways revs will be up when you're not towing, and your mileage will go down. Unless you tow frequently it might not be worth the change. Another thought..... the same money in other mods will help the truck pull the taller gear ratio. I put a Jacobs ignition and some underdrive pulleys on, and did some intake mods. The extra torque lets me keep the truck in OD if I want to...

 

Pastmaster- 285/265/235 are all tread width only. Your height is determined when you combine this number with your aspect ratio (ex. 75/70/60). A 235/70/16 has a sidewall height that is 70% of 235mm. So changing width or aspect ratio or both can change tire height [ex. a 235/70/16 is approx. the same height as a 285/60/16). 50mm more tread hitting the pavement; lower profile (60) combined with wider tread (285), but still has approx. same sidewall height.]. Increasing width but not changing the aspect ratio yields a taller tire. Lowering width is opposite. Lowering your aspect ratio (from say 70 to 60) but not changing you tire width yields a shorter tire. Raising aspect ratio is opposite. If you actually measure tires from several manufacturers you will find out that they vary some (we are talking mms.)

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2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification,Superchip,
Dynomax ultra-flow welded 3" cat-back.

 

I ordered my gears from Randy's Ring & Pinion in California. They really know their stuff. I learned my P265/75R/15 tires are 30.5 inches tall. Replacing the 3.55 gears with 4.10 will increase my RPM's but I am willing to give up a couple of mpg's for the extra power. I have some mountains to pull a camper over and it's really a strain with the 3.31's. We have a local programer who sells the computer chips at reasonable prices and that's my next purchase. Thanks for the help.