I have a 2010 f150 5.4l with 3:55 gear ratio. I am installing a 6 inch lift kit with 35x12.5x18 pro cam tires. Although I have the trailer package with a radiator for the transmission should i be concerned about damaging the transmission? I've read a lot about fitting the gear ratio to the tire for enhanced efficiency and performance. Just wondering if there is no change to the gear ratio will the transmission suffer an earlier death?:

 

If you really want the transmission to last a long time then keep the tranny cool and don't plan on towing much. Keep up on fluid changes. Seems like you're already on top of that so I'm not telling you anything new.

FYI - Truck is going to be slow as the hills unless you change axle gears. It's going to look cool, though.

 

do these transmissions have a drain plug, dip stick? or does it require dropping the pan?

 

On the passenger side of the transmission (under the truck), there's a stubby little bolt that's actually the dipstick. easy to find, it's right there bright yellow.

 

the difference it tire size is going to approx 9%

meaning:
your new effective gear ratio will be about 3.25
or
to keep the same effective gear ratio you would need to change to 3.87 (no such thing, so 3.73's would be your closest bet)

i don't remember all the gear combo's available in '10, but i think they offered something in that 3.31 range with the 5.4L. so you are in the ballpark with what was offered from the factory.

you will feel the difference, for sure. but i don't think i'd freak out about it. might be worth having your speedo recalibrated though... it will be way off as you get up to highway speed.

 

Thanks for the feed back! I have3:55 gear ratio. based on the comments I wil leave the gears as is and see how big of an impact it has on performance. hopefully minimal since its a v8 with the towing pkg, will see. Thanks a bunch!

 

This guy can help you with that. I run about the same size tires with a 2" LK same rear/engine. Mike knows how to wake 'em up

 

Which guy are you referring to? also, i had a 4x4 shop tell me that i could increase horse power by 15% by increasing air flow and changing the electronics. the mentioned this might be an alternative to changing gears, also said it would improve gas milage. any truth to this? if there is does anyone have recommendations on the best components?

 

Hi Jake, D8Chumley included a link where he highlighted "This Guy" click on those blue letters and it should take you over to 5 star tuning. I haven't done anything like that with my truck, but 5 star seems to be a very reputable dealer on these boards as I've personally only seen smiles from the people that received tunes/modifications from them.

 

Here's the link to 5 Star:
5 Star Tuning | Custom Dynomemeter Chassis Tuning Products and Services

The man's name is Mike Butler. He's a site sponsor, as well as being a vendor for SCT programmers.

 

Thanks bro! I should've just done that instead of trying to be fancy My bad

 

easy to find, it's right there bright yellow.

 

if you are truly worried about your trans and performance taking a hit, get your axles regeared to 4.56

that will reset your final driveline ratio back to nearly stock. many many guys also report their MPG's in town going back up.

While you are in there, getting a traction adder wouldn't hurt. I myself am about to get my PSD regeared with a detroit rear, and true-trac front and 4.56 gears.




your highway MPG might take a 1 mpg hit...but then again, you are upgrading from 32" to 35" rubber. So your highway mileage is going to drop regardless. new gears will make it less so

 

Raptors have 35's, what do they run for gears- 4.10s?

 

yes, they have 4.10's