the1adman wrote:
Your right Dreeder get a diesel isn't advice that helps me. I love and have owned diesels for 20 years but sold my 2006 1 ton and 5th wheel and now own something my new budget can afford. For 5500 lbs a 1/2 ton should be fine but figured a 3/4 ton Hemi wouldn't break a sweat. From my calculations for the tire size increase it put the gears at about 3.50 from 3.73. I am thinking 4.56 gears would be needed to haul any significant weight with slightly larger tires on this truck. Cost of swapping out gears in front and rear diffs just not worth it. Probably cheaper to get a different truck. Just surprising cause the truck runs and shifts flawlessly when its empty.
I think the stock tire size on Dodge 2500 is 245/75-16.
I think the stock tire size on the Dodge 3500SRW trucks is 265/75-16.
245/75-16's are about 30.5" diameter.
265/75-16's are about 31.5" diameter.
295/75-16's are about 33.5" diameter.
So, with 295's, you have from a 2" to 3" difference in tire diameter from stock, depending on whether your stock tire size was 245 or 265.
245 / 295 x 3.73 = 3.10
If your stock tire size was 245, your effective axle ratio with 295's is about 3.10. To 'fix' your effective axle ratio back to stock 3.73's, you would need to swap to 295 / 245 x 3.73 = 4.49. Since 4.49 is not an available ratio, 4.56 would be the closest available ratio to swap to.
265 / 295 x 3.73 = 3.35
If your stock tire size was 265, your effective axle ratio with 295's is about 3.35. To 'fix' your effective axle ratio back to stock 3.73's, you would need to swap to 295 / 265 x 3.73 = 4.15. Since 4.15 is not an available ratio, 4.10 would be the closest available ratio to swap to.
If it were my truck, and I wanted to keep the 295 tires, I would swap to 4.88's, which is one step beyond the required 4.56's to fix it back to stock. 4.88 fixes it to an effective 245 / 295 x 4.88 = 4.05, so 4.88's would be similar to having stock 245 tires with 4.10 gears.
Cost of a gear change on a 4wd 3/4-ton or 1-ton is about $1500. That's what it cost me to change from 3.55 to 4.56 in my gas engine F350 4wd.
If you don't want to swap the gears, then swap to the smaller stock 245 size tires. Even then, you may still wish for 4.10 gears instead of the 3.73's.
