Explain Gear Ratio?

[JohnIrish]

Hi..

Help me understand the gearing.

Chevy's have 3.73's normally and 4.10's for towing. Is this the number of "teeth" or what in the rear end? I think the Tundra has 3.95's to fall between the two.

Why is the Titan different and able to use the transmission to cause an overall gear ratio of 410 with a lesser gear in the back? Wouldn't Fords and Chevy's transmission have the same effect?

I understand very little about this subject.

I wish they would offer a tow package and off road without the gear change. The mileage is a concern for me.

thanks

JohnIrish

[Doghouse]

Welcome John,

I am not an engineer, but I think I can get you 90%.

The rear end numbers are the gear ratios. 4.10:1 or 3.73:1. so the drive shaft turns 4.1 times for 1 axle rev.

The difference between nissan and most of the other manufacturers is that you have a 5 speed automatic. So due to the lower transmission gear ratio, the rear axle can have a larger gear ratio.

I hope that helps.

[bestatchess]

Originally Posted by Doghouse

Welcome John,

I am not an engineer, but I think I can get you 90%.

The rear end numbers are the gear ratios. 4.10:1 or 3.73:1. so the drive shaft turns 4.1 times for 1 axel rev.

The difference between nissan and most of the other manufacturers is that you have a 5 speed automatic. So due to the lower transmission gear ratio, the rear axel can have a larger gear ratio.

I hope that helps.

Indeed, you need to look at the final drive ratio, not just the differential. The final drive ratio depends on the transmission, the transfer case, the differential, and the outer diameter of the tires.

[JS02]

The actual gearing for the truck is the combination of gears of the transmission and rear differential. The Titan's transmission is geared lower than other pickups. If you want to compare actual ratio's multiply each transmission gear ratio times the differential ratio. This will give you a comparison between trucks. You will find the Titan has a low first gear and spreads the ratios nicely all the way to fifth or overdrive. Fords and Chevy's just have 4 gears to work with.

A lot guys in the GM forums feel their 4.10 geared trucks do about the same as the 3.73 geared trucks. Not as good on the highway cruising but better around town. The Titan has much more low end torque so I think the 2.94 gears will do better on fuel and that's what the forum members seem to be showing. Most of the things you give up without getting the Big Tow and Offroad packages are things you don't get in other pickups such as VDC, trans temp gauge, Rancho shocks, and big mirrors.

[ChuhBaca]

Also, the tire size figures into the final drive ratio. Bigger tires will increase your final drive (lower numerically).

[Titanparts1]

Originally Posted by JohnIrish

Hi..

Help me understand the gearing.

Chevy's have 3.73's normally and 4.10's for towing. Is this the number of "teeth" or what in the rear end? I think the Tundra has 3.95's to fall between the two.

Why is the Titan different and able to use the transmission to cause an overall gear ratio of 410 with a lesser gear in the back? Wouldn't Fords and Chevy's transmission have the same effect?

I understand very little about this subject.

I wish they would offer a tow package and off road without the gear change. The mileage is a concern for me.

thanks

JohnIrish

Check out this glossary!!
http://www.radleyauto.com/glossfz.htm