Differential swap

wes wrote:
dodge guy,

Thanks for the voice of experience. With my lighter TT (8k), I only drop to 2nd once in a great while around ND with my Excursion. But it might be pretty common to hit 2nd in the SD Black Hills, or mountainous regions. It already seems like 2nd is then a bit too low, even for 3.73's, but there is no intermediate gear between it and 3rd. Since 2nd sometimes already spins the rear tires, 1st is way too low, unless one has 4x4 engaged to spread the traction.

My buddy has an extended cab 2000 F-250 and pulls a 5vr closer to 11K with 3.73's. He shifts to 2nd more often than I, even occasionally on the ND I-94 if bucking a good wind on a hill. He recently likely overheated his tranny, blew a tranny seal, and lost his torque converter in the Black Hills. I will say that he probably had a hard time maintaining over 35 mph in some of the tight curves, which might have meant the converter was at least not frequently locked up.

One other thing I noted is that my 2000 Ex and buddies 2000 F-250 seem to shift slightly differently when not towing. My Ex seems softer, gentler, something I do not consider a durability advantage. Even my 2000 diesel shifts mushier, although it holds OD well on hills (3.73's). As second owner, maybe my buddy has an internal shift kit and doesn't know it.

Wes
...

Yes, that 3-400rpms makes a huge difference! my X was a chore to tow with when I had the 3.73`s. it always seemed like it needed a few hundred rpm more in any gear! With the 3.73`s at 65mph I couldn't hold O/D. and in 3rd at 65 it was under the rpm where it made its best power for towing. I would have to speed up to 70 to get it into the power band. with the 4.30`s it now holds O/D and it works less at 65 now too!

3.73`s are good for lower weight and less frontal area, but more is needed for heavier and taller trailers.