what axle ratio?
 

Hi Everyone,

I have a landscaping company in San Francisco and currently drive an 03 f350, 6.0., cab and chassis. I do 90 percent of my driving in the city and pull a dump trailer in excess of 16K up and down the hills of SF on a regular basis. I bought the truck new, am on my 3rd tranny and second rear end. I think its because it has 3.31 rear end and too much pressure on the drive train.

Anyways, I am buying the new 6.7 and can't decide whether to go with the f450, 4.3 gear ratio or go with the 4.8 gear ratio which would require that I get the f550.

Also, although I want the new truck now, should I wait 6 months or so for the 2012 or does it not make a difference?

Thanks all,

Paul

The 6-speed trans in the 2011 has a much lower 1st gear, so the differential doesn't have to be as low. 4.30 will be plenty low, it will seem probably two times lower than the 3.31 behind your 5-speed. 4.30s would have been a good fit for your 6.0L with that kind of usage.

I have a 6.0 with the 4.88's, works fine for that setup, but on my ordered 2011 6.7 I skipped the 4.88's in favor of the 4.30's. seems better as the motor makes more torque at lower rpm and it does not rev as high. I think that 4.88's would be overkill and keep it reving out of its power range.

4.88 gear
 

Thanks for the imput. If using the truck to haul 16k dump trailer up and down the hills of San Francisco on a regular basis doesn't warrant the 4.88 gear ratio, what is the 4.88 made for?

Thanks

You can get the 4.88s if you want, but if you're 6.0L did it with 3.31s then the 2011 won't even break a sweat with 4.30s and the lower 1st gear in the transmission. If you get the 4.88s you'll hate it on the highway.