Installed 4.88 Gears in my 2016

Read the whole thread!

 

I did read the whole dang thread! SEVERAL TIMES!

 

Rehearing is something like this. Although Toyota gears go in the other direction

 

I just got through the first break in period on my truck. Cant wait to get to fully test it out.

 

Regearing absolutely does increase torque at the wheels. That's what gears do, multiply torque.

 

Nope.

It changes the application of the existing available torque. It does not increase torque.

http://www.autos.com/aftermarket-parts/how-does-a-gear-ratio-affect-torque

 

By that same token, stickers also increase horsepower.

 

Wow.. that's an awful article. the 2 examples it gave were a 1st gear ratio of 2.97 and 6th of .56, saying that the wheels turn once for every 2.97 engine revolutions in 1st and every .56 revolutions in 6th. This is completely incorrect.

The article ignores transfer case and differential ratios. It's simple to take the TC out of the equation by assuming a 2wd vehicle or a high range ratio of 1:1, but take that example of 2.97:1 1st gear and a 3.91 rear axle ratio. the wheels would spin once for every 11.6 engine revolutions (2.97x3.91).

If the engine makes 300ftlbs of torque, that would be just under 3500 ftlbs at the rear wheel (2.97*3.91*300). Now let's try the same with a 4.88 ratio (2.97*4.88*300), we get 4348 ftlbs. That added torque is why a vehicle feels faster with shorter gears. The tradeoff is less speed at a given engine RPM. It's the same reason we start off from a stop in 1st gear, or use low range offroad, more torque at the wheel.

 

You clearly don't know anything about power transmission.

I just have a mechanical engineering degree, own an offroad shop that has installed 1,000s of gear sets, travel the world to take part in various offroad events, and am the East coast distributor for a large ring&pinion manufacturer. But what would I know about the subject?

Thanks for the warm welcome to TW

 

I apologize. Yes more torque less rpm. I misread and through the you were referencing power like others earlier in the thread. No ME here just Civil we don't care about rotation.

 

Haha,, no problem.

What do they say, MEs build weapons, CivE's build targets?

 

$900 each or both front and rear diff?

 

Clear water is right, gears don't create torque it simple trades rpm for torque.

Torque T=F(Force) x d(Gear)
HP P=W(Work/Torque) / T(Time)

To travel 60 in on 286/75/16 and 3.9 gears seams sluggish since the engine is at a lower RPM range which the engine HP outputting is lower. Having 4.88 gears and driving 60mph the engine is at a higher RPM range closer to the power band so its driving with more power and can rev faster when needed. Gears just put the required demanding torque at the wheels at the optimal level of power for mileage or power for torque depending what the vehicle is gear for.

 

We're really splitting hairs over semantics here.

Correct, gears don't create torque, they don't generate force. Gears transmit and multiply torque, so by swapping to a shorter gearset you'll end up with more torque at the wheel.

 

This is genius-----I've needed this quote a long time.

I also am a degreed engineer so I'm loving all this gear talk.......and learning a ton.

 

How's it still running? Any better after a few miles?

 

Did the trans learn with the gears any better?

 

haha i knew i would find some fellow MEs in this thread.

 

Good question

 

I guess I am waiting on a crush washer!
My shop told me the last guy that did it, is extremely pleased.