Ok guys since I was away last week you have peaked my interest in changing the gearing on my X. I like all tehopinions here so I figured I woud ask.

I have a 2000 4x4 V10 with stock 4.30 gears I think that the origional tires were 31's. I have since added a 6 inch lift and 315 x12.5x16 BFg AT's i tow a 13000 + lb tow hauler. Yes thats right 13K+. In some of the discussions before it was suggested to moce up to a 4.56 or 4.88 gearing,. This would then change me back to close to what the truck had been designed for.
Whats are you thoughts.

I get 13 MPG at about 70 ish not towing, TOwing on the falts I get 7. and 5 uphills. I live in So Cal and we have hills.

Thanks for your help

 

I would say since ur towing 13k 35's go with the 4.88s

 

Is it really goning to make that big of a difference? Has anyone else changed ou the gears for bigger?

 

X_hemi_guy changed his truck from 3.73 to 4.30. Now granted he has stock tires, but he said it made a big diff. Besides a supercharger, gears are the best mod for the v-10

 

kappy,

It is my STRONG opinion that a 2V V10 should be mated to a final drive of 4.30 when in direct drive (3rd gear on our 4R100's) for STOCK 31.6" tires.

Given that your tires are NOW 35"?...a rear end gearing of 4.88 would achieve a final drive in 3rd of 4.41. A bit deeper than the 4.30's...but given the LOAD you are tugging...deeper isn't a bad thing.

You can run your own numbers here : https://www.ford-trucks.com/calculat...re_sizes/a-td/

For a point of reference...I don't tug anywhere near what you do...so scale my input accordingly...

I roll down the road at 17,000#'s. I have stock 31.6" tires and 4.30's. This summer we pulled on I-64 in West Virginia thru the Appalachians...there are a few 5 mile long 7% grades...IF (big if) I could hit the hill at 3200RPMs I could pull the hill at 70mph...lose 3200RPMs and I'd have to down shift to 2nd and only pull the hill at 60 BUT at 4200-4500RPMs.

IF I had slightly DEEPER gearing...I'd have slightly higher RPMs at slower speeds and wouldn't have to run 70...

So in my experience...this V10 LOVES 3200RPMs...with the taller 'effective' gearing you currently have (3.88's)...you likely experience frequent downshifts on those hills given the weight you are rolling down the road at.

I'd have to say...swapping my 3.73's to my 4.30's was THE SINGLE BEST thing I've done on my Ex.

BTW...you will be able to SELL those 4.30's in a HEARTBEAT...that is the PREFERRED gear for those of us that tow with STOCK tires...

Hope this helps.

joe.

 

joe, u think 4.30s would work well with 33's?

 

Over current 3.73's?

33's and 4.30's would produce an 'effective' final drive (in direct 1:1 drive) of 4.10...a good gear.

What is the 'intended' use of the truck after the gear swap?...if towing HEAVY (near 10K#'s)...If you are paying to swap already...I'd opt for 4.56's and that would result in an 'effective' final drive in direct drive of 4.34...BETTER solution IMO...

BUT if NOT towing...then the 33's and 4.30's would be a good combo...it's all in what your use of the beast will be...deeper gearing will 'slightly' hurt MPGs...but with how heavy most of our right foot is...I don't think you would really notice it...well I guess if someone was a salesman that ALWAYS drove constant straight highway trips...sure the deeper gears would hurt MPGs...but in 'mixed' driving...too many factors BESIDES gearing will alter tank to tank mpgs...

joe.

 

I tow 6-7k somtimes. I dont care about fuel mileage i just want torque! I somtimes use the truck to pull small trees and stuff out of the ground

 

4.56's and 33's would put the motor smack dab in the torque sweet spot...

4.30's and 33's would have you slightly on the low side of the sweet spot most of the time...

If I were paying...I'd go 4.56...then if you ever decide to go 35's on the truck...you've already got some room on the gears...vs having to possibly upgrade AGAIN...

joe.

 

Im deff gonna stay with 33's. I plan on buyin another truck sometime in the near future (mayb a 99-02 350 dually, 7.3 4x4)

 

I called a local gear/driveline shop that does alot of work for the wheel drive community. They said stay with the 4.30 going any higher would scew up the non towing range. that would put the 60 mph in a 1:1 range at 2500-2600rmps Does that sound right?

 

4.30's and 31.6" tires (what I have) in 3rd gear at 65 is 3000RPMs

4.88's and 35" tires (what I proposed) in 3rd gear at 65 would 'likely' be 3100RPMs

I can't see HOW that would screw up MPGs...well it will be WORSE than what you have NOW...but what you have NOW isn't a good towing gear...IMO for the WEIGHT you are towing...sorry...

You are likely with your 4.30's and 35" tires in 3rd gear at 65 at 2600-2700...right?..so YEAH the 4.88's would be worse for MPGs...but you are tugging 13K#'s!!!...you need GEARING...IMO...

 

4.88s and 35s wouldnt be that much worse. What by .5 mpgs to 1 mpgs less?

Did u tell him how much weight u were towin? If u did, Tell the guy at that shop to get his head out of his as*

 

See that why I love your opinions.... Real life situations....

 

Thats why FTE is numb 1!