Power shuttle problem.....need help please

[sampsue]

Hello, I have a Challenger MT455B 4x4 with the 8x8 gearbox. The tractor will start fine but will only move if the Differential is locked. When in 2wd and/or 4x4 it will not move fwd or rev and the indicator arrows do not light up or blink. There doesn't seem to be a blinking error code as far as I can tell. Also, with the tractor in neutral, 2wd and rear diff unlocked the green 4x4 symbol lights up on the dash if im pressing the brake pedals. The fuses are good, and I've cleaned and played with all the connections. After reading many post about the power shuttle I replaced the Bottom of Clutch switch but that didn't help. I'm trying to learn as much as I can cause I hate having to trailer it to the dealer for obvious reasons. I do have the factory repair manual and I'm making my way through it. If anyone has had this problem or can assist in any way I would greatly appreciate it. Thank you !

Jonny

 

[Richardjw~]

seems like you have a leak in the low=pressure regulated circuit, i'm not familiar with this tractor but as rule the Diff, MFD, trans clutch packs & PTO work around 280psi.
What you are describing sounds like that pressure is draining away through the difflock disengage circuit.

 

[sampsue]

Richardjw, Thanks for the info......will look into that as soon as I can. The Challenger tractors are the same as the massey fergusons. I imagine theres a test port in that system.

Thanks again
Jonny

 

[wood]

Did you find problem with drive?

 

[BuMach]

probely had bad seals in 4wd clutchpack.. most common problem with the transmissions.