I have a 2wd 7.3 and would like to cruise at 75 or 80. Will be doing very little towing. Want to know if there is a better 5 or 6 speed trans that will give the same take off but bring the turbo out of boost at 80.

 

i;ve been researching the same thing for my V10. I don't think its the transmission as much as the final drive ratio on your axles. But if you have the 4 spd like I do, a few more OD gears would be nice. I'm pretty sure I'm going to switch my 4.30s for 3.55s or so.

Has anyone put one of the new 6 speed autos in the X?

 

What you both are looking for is a gearvendors overdrive.

Gear Vendors Under/Overdrive Ford Truck-Car-Van 2-Wheel Drive 4-Speed and 5-Speed Automatics.

 

At 80mph, you'll use more fuel with the turbo "out of boost" to maintain 80mph than a rig with the turbo "in boost"

Or are you looking for lower RPM's at that speed?

Two different animals.

Stewart

 

Sounds like my 3.73LS would be a nice fit, cause Blue sure could use a set of 4.30s!

 

Exactly what I was thinking (but White of course). Love to get some 4.30's...

 

No tranny is going to improve mpg much if at all. It's the final drive that counts.

 

Guess I need to find out my final drive. Where do they post the options list on the vehicle? I remember my old cars had it.

 

If the new tranny going in has a better ratio than the 4r100 4th at .71:1 it will. Changing the gearing by 10% or the Od gear by 10% mathmatically has the same effect.

I know that the 4r100 and the 5r110 have the same OD gear so that change will not help travelling mileage at all.

I do not know which tranny will bolt up to the V10 either. I do know that most people change gears first, or go with gear vendors.

I haved contemplated this for a long time. The cost of a different tranny or the gear vendors tranny would pay for itself in about 80000 miles. I'd rather just live with what I have. gears are cheaper. I changed gears for pulling power and dropped about 1mpg on the road going from 3.73s to 4.56s. I know the 37"s dont help.

 

I'm not so sure anyone has succesfully swapped in a 5 spd to a V-10 or 7.3 EX. Lot's of computer and wiring issues.

TD has the answer, the aftermarket OD unit. Not so sure it would ever pay for itself in fuel savings, but looks like a cool mod.

 

If you want MPG out of your tranny then put in a better torque converter. I really like the x6tc I got from racerx. Otherwise you could trade those 430s to just about anyone. You could also get taller tires. Its all about ratios

 

Seen both a ZF-5 and a ZF-6 handshaker in Excursions. Nifty. I know...not the same.

 

I almost put the zf6 in my swap but you end up needing a bunch of mods to make it work, not the least of which is the rear vents that run through the floor right where the shifter wants to come up. the Ex is to big not to have rear heat/ac