Discussion Starter · #1 ·
Where is the best place to get some 4.30's for an 02psd front and rear?thanks
second that, also don't forget that the rear will take a 10.25 ring and pinion incase you wanted to look around for some factory gears some one might be selling on the cheap.
All '99-up SRW Superduty pickups have a 10.5" ring gear in a Ford axle. But if the rebuilder knows what he's doing, the 10.25 replacement parts for the '97 and earlier Heavy duty pickups can be made to work.Now i am confused.Do i have a 10.50 or 10.25?
It may be either one.what is the front?A 50 or 60?
2002 F-250 4x4 had LT265/75R16 stock and 3.73 ratio.With 325/60/18's would a 4.30 be to much???
Thanks for all the info.You really seem to know your stuff.I think the 4.10 will get me where i want to be.All '99-up SRW Superduty pickups have a 10.5" ring gear in a Ford axle. But if the rebuilder knows what he's doing, the 10.25 replacement parts for the '97 and earlier Heavy duty pickups can be made to work.
It may be either one.
The Source Book specs say your front diff is a Dana 50. However, the source Book is published before the model year begins. If memory serves, 2002 was the model year that Ford changed to the Dana 60 after the model year began. So it depends on when your pickup was assembled - and no I don't know the changeover date.
2002 F-250 4x4 had LT265/75R16 stock and 3.73 ratio.
LT265/75R16 tires have 655 revs/mile.
LT325/60R18 tires have 626 revs/mile
That's 4.4 percent difference in revs/mile.
3.73 plus 4.4 percent = 3.89 ratio needed if tire diameter were the only factor.
Plus you would need a smidgen shorter legs than the tire diameter (revs/mile) math answer to compensate for the increased aerodynamic and mechanical drag of those big meats.
Therefore, to get around the same or a bit better performance with the big tires you had been getting with stock tires and stock gear ratio, the 4.10 ratio would be close to perfect. The 4.30 ratio with the big tires will be better for heavy towing (trailers over 10,000 pounds) in mountains or the hill country, but it will cost you even more loss of MPG because of the higher RPM required for the same road speed.
So the short answer is: yeah, the 4.30 ratio will probably be "too much" unless you plan to tow heavy or win drag races, and don't care about fuel mileage.