Question Transmission wont shift to hi gear

[dewshooter]

hello all. I have an issue with my 2000 F450 4x4. It seems to not always want to shift into the highest gear, around 80-85 km/hour it will just rev past 3000 rpm without shifting into the next gear. Its about a 50/50 thing. sometimes it will sometimes it wont. I read about a speed sensor on the rear diff, could this be my problem?? any help is appreciated, thanks.

PS- sorry- it is a 7.3 deisel

 

[dewshooter]

I think....

there is slight chance I may have been hitting the overdrive off button on the end of the shift lever...the button housing is broke off so it is easy to depress by accident when engaging the transmission... guess I will keep my eye on that and see if it does it again.

 

[JLDickmon]

there is slight chance I may have been hitting the overdrive off button on the end of the shift lever...the button housing is broke off so it is easy to depress by accident when engaging the transmission... guess I will keep my eye on that and see if it does it again.

well, try that first...
if not, you know where we are...

 

[elliotthere]

hello all. I have an issue with my 2000 F450 4x4. It seems to not always want to shift into the highest gear, around 80-85 km/hour it will just rev past 3000 rpm without shifting into the next gear. Its about a 50/50 thing. sometimes it will sometimes it wont. I read about a speed sensor on the rear diff, could this be my problem?? any help is appreciated, thanks.

PS- sorry- it is a 7.3 deisel

The overdrive button is just to shift in & out of fourth gear, did it feel like as if it was in neutral ? If it did take your foot off the gas & down shift to 2nd gear then back up to drive if it works you may just have a sticky valve or solenoid.

Good luck Dave(elliotthere)

 

[dewshooter]

Well, I intentionally turned the OD Off and the truck does exactly what it was doing whne I thought there was a problem. Funny thing was, first itme it did it, I stopped for fuel, of course turned the truck off, then restarted when leaving and it was fine. So shutting the truck off sets that button back to original position, hence no problem. I have only driven the truck 3 times so far but I figure that was the issue. Have to replace that shift lever one of these days. Thanks for the help and suggestions fellas.