Hi Guys,

Im looking to get a little more pep out of my truck on the road. Im tired of it constantly going out of overdrive with the smallest grade. It has always felt so bogged down. It has 3:31 Gears in it and a 4R70W. Im running stock tires and am looking for a good replacement gears that wont sacrifice mileage but will will improve low end/highway power. My buddy has a similar truck with the same engine but different gears (his gear tag identifier is missing) and it great on the highway as far as staying in overdrive.

Open to any suggestions or thoughts you can offer!

Thanks all

Jer

 

How fast do you drive on the highway?

If it's 70mph or less go to 4.10 but regardless don't chose anything less than 3.73.

 

Typically 70-80 Range on the interstate. That Where I have to Keep it if I don't want to drop out of overdrive as much. Will 3:73's make it feel a bit more peppy for the passing gear/ acceleration. Hoping to make the truck feel lighter on its feet lol.

 

Yes 3.73s will improve performance across the board and it should actually improve fuel milage since the engine will be under a lighter load and trans will be downshifting less.

 

Excellent. Last question. Any recommendations on sites where I can purchase 3:73's?
Appreciate the help!

 

I have always had great service and products from Randy's Ring & Pinion

Personally I would go with 4.10s, but then again I am a gear wh*re....my 2004 V10 Excursion has 4.30s. I found 4.10s to be tolerable in my last two 1993 F150 Lightnings w/5.8L engine.

If you are going to spend the time and $expense$ to change gears, go big...

 

I am very green when it comes to gears. What differences can I expect from 3:31's to 3:73 or to 4:10's? Would the difference be instead of being at 2000 rpms at 70MPH, I may be at 2500? Almost like bike gears, easier to start our in a lower gear vs a highier?

thanks!

 

The larger the number the more torque multiplication you will have at any given RPM. There does come a point of diminishing returns and needlessly over-revving the engine at cruising speeds. Yes, there will be an RPM change associate with any gear change. The same can be said for taller or shorter tires. Those will also change the effective gear ratio.

 

You say your truck has stock sized tires on it now, does that mean 235/75-15? If so then if you were to go with 4.10 gears and found the motor was reving too much on the highway you could up the tire size to 31" or 32" and reduce engine speed back down.

 

Yes 235/75-15. I will probably go with your suggestion of 3:73's. something that make it feel more peppy but without having to go with different tires. Im somewhat limited on the money I can spend lol. Im looking at the site that was recemmonded to me.

Is it as simple as ordering the gear and pinyon to replace this? Or do I need to order additional items for the shop to install with it?

Thanks!!!

 

If you are going to open up the axles it's best to plan on replacing bearings, races, crush sleeve, limited slip clutches if equipped. This project is not going to be cheap, especially if you have a shop do it. While it is not rocket science to do, it does take some special tools and some training to perform properly.