Bought 91.5 4x4 with 138K Speedometer off though

[GardnerM]

Hi All, Bought a 91.5 with the 46rh behind it and it shifts like a dream exept OD hunts and drops back down as soon as I hit a grade. The truck is here to stay so I ordered a TPS delete kit . The speedo looks to be off by about ten. Recon its a speed sensor on transmission ? Hoping thats it, should run just over 100 bucks. Could be why it doesnt want to stay in OD but .....

 

[RWherley]

It sounds to me like some has put taller tires on it or maybe changed the rear gears in the truck at some point, that's what messed up your speed-o wheat you need to do is change the speed-o drive gear in the trans. that should fix it.

 

[GardnerM]

It sounds to me like some has put taller tires on it or maybe changed the rear gears in the truck at some point, that's what messed up your speed-o wheat you need to do is change the speed-o drive gear in the trans. that should fix it.

Its all stock, tires rims axles... just looks like its at least 10mph off. Run it through first three shifts perfect no slip...then OD will only shift in when you let off it ,then ease back into it. Soon as you hit a hill and want to stay with traffic it drops back to third. Wonder if the getrag sending unit is the same one as I have an early 91 w stick in the weeds that rusted out cab mounts....

 

[DVolk]

might be dirty connection