3.31 gears at 40,000 lbs gross.
Just to give a bit of a feel for how different gear ratios would behave while towing I locked out 10 then 10th and 9th then added them back again while travelling on a straight stretch of road w...
Forum Discussion
blt2ski wrote:
Roy,
If that frod with 6.15 gears had 40" tires vs standard 32" tires. Might be a good setup.
2nd setup looks kinda normal for some OTR rigs where top rpm is 2000!
Tire diam, tra s ratio's, all effect how a RA ratio should be at.
A rig with 28" tires, 3.42 gears, another with 3.73 and 30" tires, or 4.10 with 32" tires, assuming same trans, engine, all have the same shift points, should accelerate and pull the same load equally. I'm positive there will be some difference's, but in reality, nothing too major.
Marty
Funny enough, I just recently put the smallest, highest payload tires on my old V10 Ram, because re-gearing may cost more than the old truck! I chose 235/65/16C, off of a Transit van. Compared to the 31.5", I made my 3.54 effectively into a 4.00.
My point though, was folks only look at rear end ratios. The 4R100 has a 2.75:1 1st, and the 10R140 a 4.615:1.
I bet if we did a random poll of what's better for towing: old 4 speed Ford with 6.10 rear end, or new 10 speed Ford with 3.31. 9 out of 10 would pick the 6.10 rear end without thinking twice.
