turbo 400 wont shift

[4x4k20]

i have an 85 m1008 the 400 will not shift i have replaced the filter / modulator vavle checked the kick down switch only thing i havent done is change the vac regulator could that be what causes it not to shift ? i tryed to by pass it but if i do that it doesnt wont to go in drive it acts like it slips but if i hook it back up to the reg it will go rite in drive but still doesnt shift any suggestions ?

 

[BARRAZA]

Doubt that it is caused by the vacuum regulator valve. The tranny should shift with it disconnected, just late and harsh. First thought was a detent switch or stuck detent solenoid but the no engagement in drive may be the indicator of a serious problem. You need to run a pressure test to nail it down.

 

[Diesel Dan]

I would check the vacuum pump. Make sure it is producing enough vacuum. It should shift without vacuum, but you'll need to rev it pretty high.

 

[rugger03]

I had the same problem in my M1009. It was shifting just fine, parked it. the next time i went to drive it it wouldnt shift out of first. Turns the govenor was sticking. you can try taking it out and cleaning it(didn't work for me), or replace it as my tranny guy sugusted. No more problems for the last 20,000 miles. Hope this helps, rugger

 

[imiceman44]

Like rugger said, I have seen that same question so many times here and on the second generation K5 forum in the past month.
This behavior is exactly what a bad governor will do.
I have seen some sticky, some with broken gears, some with worn valves, and sometimes it's someone rebuilding the tranny and putting a different governor that was meant for a racing car with lighter weights and stronger springs.

 

[4x4k20]

i didnt even think about the governor i will check it out

 

[4x4k20]

little gear on the governor is stripped out hopefully a new gear will fix my junk.

 

[imiceman44]

I knew it.
/forums/images/graemlins/thumb.gif
Glad you found your problem.