Problem with M920 Transmission

[vinceM920]

I have an M920 I put a dump bed on, runs 40hrs a week. GREAT GREAT truck! Trans has been fine, put in line oiler have had no problems till today. stoped at stop sign, down shifted to 5th to start out, now the truck wont move. put 10oz air tool oil thru the ambilical on shifter. no better. Every thing sounds like it always has. when I rev it to move, nothing. Also if I pull it in 1st gear to engage the PTO it grinds, never done that before, once in, it will not raise bed. THIS TRUCK IS LOSING WORK. Does anyone know any checks or tricks before I have to lowboy it to a transmission shop and pay through the nose to people who know nothing about it?

 

[NDT]

I am dreading the day mine does this. Almost always the prob is in the air manifold on top of the trans. It comes out thru the floorboard. Cat has most of the rebuild parts.

 

[jcappeljr]

I will pm you RRacings #.Hes a member on here.

 

[wreckerman893]

I will pm you RRacings #.Hes a member on here.

He is the CAT tranny guru on here......he can talk you though a trouble shoot and can help you source parts. Very good guy to deal with.

 

[Construction]

Take off the airline from the outside passenger tank that feeds the top of the transmission. Fill it with ATF, reconnect, start truck, let air pressure build, and shift through the gears. Do not move yet. Cut off truck, drain off air from tank. Repeat. Repeat. Repeat. Run a quart through. This will take 1/2 a day. Take off umbilical chord, fill it slowly, go through the same process.

This has worked for me.

 

[86m1028]

Hey Vince

1st check all your air vents !!!
I told you about mine doing this (after being parked for a long time).
We have a little bug down here that likes to plug holes.
I found air release port plugged & cleared it, trans shifts fine now.
I have also done some of what Construction has done with good results.

Good luck