Stage II of 2012 Superduty build... differential ratio questions.
#1
Stage II of 2012 Superduty build... differential ratio questions.
I have a 2012 crew cab short box ford superduty FX4 6.2L. yes it is a gasser. yes i like it. yes i am keeping it.
factory FX4 suspension etc. rear e-locker and all. the only modification from the frame rails down is a set of 315 cooper st maxx tires. And some spiffy wheels.
I plan on getting a good suspension. Probably BDS? i am looking at 4"...But i still tow a Horse trailer from time to time (goose neck, 22 foot, living quarters, about 8500lbs empty and 10,500 loaded with horses and gear.
Yes... sometimes the trailer goes off the pavement too. But nothing crazy.
THE POINT: I want to run a true 35x12.50 R17 tire. 4 inches should net that for me. and increase clearance. But what ratio gears are in a 2012 FX4 Gasser and what should i go back with? i want a front locker too... though i have no idea what type yet
so... gears, front locker, trans cooler??, and anything else you can think of.. she will be a tank... but its my tank.
factory FX4 suspension etc. rear e-locker and all. the only modification from the frame rails down is a set of 315 cooper st maxx tires. And some spiffy wheels.
I plan on getting a good suspension. Probably BDS? i am looking at 4"...But i still tow a Horse trailer from time to time (goose neck, 22 foot, living quarters, about 8500lbs empty and 10,500 loaded with horses and gear.
Yes... sometimes the trailer goes off the pavement too. But nothing crazy.
THE POINT: I want to run a true 35x12.50 R17 tire. 4 inches should net that for me. and increase clearance. But what ratio gears are in a 2012 FX4 Gasser and what should i go back with? i want a front locker too... though i have no idea what type yet
so... gears, front locker, trans cooler??, and anything else you can think of.. she will be a tank... but its my tank.
#3
#4
Will the 4" lift and extra tire height negatively affect the horse trailer's level stance and bedrail clearance?
I don't think a '12 SD needs a full 4" lift to safely clear 35"s, my '05 EX has a whisker under 4" of lift and clears my 35"s fine and the EX starts out life 2" lower than the SD.
I don't think a '12 SD needs a full 4" lift to safely clear 35"s, my '05 EX has a whisker under 4" of lift and clears my 35"s fine and the EX starts out life 2" lower than the SD.
#5
I agree with WE3ZS that you likely need somewhere between 0-2" of lift in order to clear the true 35X12.5 tires on that 2012. The 2011+ trucks have larger wheel well openings than the older trucks and come with 34" tires as a stock option on the 20" wheels. Someone on here is running 37x12.50 tires with a 2.5" level on his 2011+ truck. I think that I would forego the lift and just stuff those slightly larger tires underneath what you have. Your truck likely came from the factory with the 3.73:1 gears since very few were ordered with the available 4.30:1 gears. With the trailer you are towing, you want to go with the 4.30:1 gears, or maybe even up to a 4.56:1 with the 35" tires. The factory tow rating for a 6.2 with 34" tires and the 4.30:1 gears is a shade over 15k lbs.
Good looking rig by the way. I like what you have done with it so far.
Good looking rig by the way. I like what you have done with it so far.
#7
I agree with WE3ZS that you likely need somewhere between 0-2" of lift in order to clear the true 35X12.5 tires on that 2012. The 2011+ trucks have larger wheel well openings than the older trucks and come with 34" tires as a stock option on the 20" wheels. Someone on here is running 37x12.50 tires with a 2.5" level on his 2011+ truck.
I happen to be at least one of the people running 37's on a leveled truck. 37x13.5x20 Toyo RT's on a Carli 2.5" level to be exact. It only rubs the radius arm just like the 35's did. I also ran 35's with no lift and had no rubbing other than the radius arms.
35's with no lift.
37's leveled.
And I just towed this through the Rockies, so it tows just fine.
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well i did some maint. and looked at it closer before i buy the parts and take the plunge.
looks like the front bump stops are hitting regularly. nice shiny spot where they paint is gone :-( i didnt think a bump stop was a constant in any suspension system.. more of a back up plan... anyone else only have like 2 inches of up travel?
truck has been on the pavement 90% and dirt roads 10% tops... i work alot so the only time the truck leaves pavement (maybe) is when i am on vacation or long weekend.
ALSO: ... why is it i cannot see any of the awesome pics yall posted? i am grateful for that! but i never get to see them.
looks like the front bump stops are hitting regularly. nice shiny spot where they paint is gone :-( i didnt think a bump stop was a constant in any suspension system.. more of a back up plan... anyone else only have like 2 inches of up travel?
truck has been on the pavement 90% and dirt roads 10% tops... i work alot so the only time the truck leaves pavement (maybe) is when i am on vacation or long weekend.
ALSO: ... why is it i cannot see any of the awesome pics yall posted? i am grateful for that! but i never get to see them.
#13
Are you talking about the bump stops in the front? Up travel is used for speed off road, down travel is for slow crawling. If you don't need much high speed action, a lesser up travel is fine. There's nothing wrong with bouncing off your bump stops occasionally. It just means your suspension isn't exactly tuned for your terrain.
#14
With the taller tires you will most definitely want to go with 4.56. Maybe even a 4.88 given what you're towing. I'm not familiar with what is available in regards to a locker system and what ratios are compatible. If 4.30's is all that can be used then so be it, but if at all possible it would be good go with the aforementioned 4.56's or 4.88's.
#15
With the taller tires you will most definitely want to go with 4.56. Maybe even a 4.88 given what you're towing. I'm not familiar with what is available in regards to a locker system and what ratios are compatible. If 4.30's is all that can be used then so be it, but if at all possible it would be good go with the aforementioned 4.56's or 4.88's.
i think a 430 gear would be ok its really flat here in south east tx
if i had mountain passes to worry about then that would be different.