e40d need help.............

[joeyjarvis23]

I installed a new ford transmission. when you floor it instantly shifts to a higher gear and falls on its face... i pull a 30 ft fifth wheel, and i had to put it in second because it kept shifting and was running 200 degrees. this was on a flat interstate.. i have replaced the vss. and cps.. im running 35" tires with 3.55 gears, also a tony wildman chip.diy intake and 3 in downpipe.. i bought the truck with out a transmission..... any advice would be apperciated....

[Patrick Feeley]

I can't help you with the tranny, but towing with 3.55's and 35's can't be optimum. Is your speedometer been recalibrated for the 35's? Cheers!

[1Dieselman]

I agree with Patrick. Maybe borrow some smaller tires in the 265-285 range and see if doesn't pull a whole lot better. That size tire with 3.55 gears you are working the heck out of the entire drive train.

[joeyjarvis23]

thanks for the help ill pretty much anything

[joeyjarvis23]

so i installed 4.11 gears and reprogrammed my speedo, it is doing better but while climbing an incline in 3rd you left off the gas a bit it will shift to forth at like 900 rpms and wont down shift unless you flloor it.. also my speedo needle is shaking over 50 mph now