th400. do I have a shift kit?

[asg13]

My transmission seems to shift out of first between 30 and 35 miles per hour is this normal with a th400 or has someone possibly installed a shift kit? Bear with me as I am a newbie and could not find my answer and I search

 

[patracy]

Doubtful. Most likely your vacuum modulator or valve isn't adjusted correctly. What truck?

 

[roveroverme]

or your vacuum pump is toast. As it happened to me.

 

[patracy]

or your vacuum pump is toast. As it happened to me.

Or, it's something as simple as a loose/rotten vacuum line.

 

[truck1]

I had the same problem in my 1028. Turned out to be a corroded hard vacuum line against the firewall. Loss of vacuum equals no shift. Bridged the break with a short piece of rubber vacuum line and a couple clamps. Shifts perfect now. Check all your lines from the IP back to the modulator at the tranny for leaks before you start replacing any parts.

 

[asg13]

M1008

 

[roveroverme]

Or, it's something as simple as a loose/rotten vacuum line.

Yes, it could be that.
I found out by having the engine run and took a vacuum line off and was putting my finger on the hose- No suction equals either. broken hose or vacuum pump.
I took the tee off the vacuum pump and did the same thing again, no suction.

 

[Warthog]

The TM 9-2320-289-20 tech manual has sections that cover your transmission problems.

 

[roveroverme]

The TM 9-2320-289-20 tech manual has sections that cover your transmission problems.

true...

 

[asg13]

The TM 9-2320-289-20 tech manual has sections that cover your transmission problems.

available on steel soldiers or do I need to purchase it online I do not have a manual that came with the vehicle

 

[moving chicane]

http://www.steelsoldiers.com/upload/CUCV/TM9-2320-289-20.pdf
download and save for best results along with the rest of the CUCV TMs

 

[Warthog]

A huge amount of tech manuals are available for free here on this site. You just have to click on the Technical Manuals button at the top of the page.

 

[asg13]

Ok.so far I have changed the two rubber hoses coming off of the VRV. Both were dry rotted. Problem still not solved. I have traceed the metal hose back to the vacuum module that connects into the tranny. Seems to be fine as well. i replaced the rubber hose that connects the metal hose to the module as well, only an 1" or so but went ahead while i was under it. No tranny fluid in the hose or module either. Bone Dry. So im guessing that means the module is in proper working order? Does the module just pull out or twist? Guessing that leaves me with needing to replace the Vacuum Regulator? Again, shift out of first at redline, which seems to be about 35 and second at 45 to 50 on the speedo. 33" tires on the rig FYI. Other then that, seems to run fine. Almost like when it does get out of first it will only stay in 2nd and third until i come to a complete stop. Tranny fluid level seems fine as well. I spoke to the mechanic that normally serviced this truck about a week ago. The original owners serviced the truck every spring from oil to changing all filters etc. So the truck is very well maintained, just this lil hiccup in which the previous owner thought it was supposed to be that way?????

 

[roveroverme]

Have you checked the vacuum pump behind the airfilter?

 

[asg13]

Have you checked the vacuum pump behind the airfilter?

No i have not..not real sure how...no means a mechanic..is there a simple way or a special tool needed?

 

[roveroverme]

yes, take the tee off on top of the vacuum pump. start the engine. put your finger on the rubber hose. you feel any suction= there is a vacuum. No or very little suction = broken diaphragm.
Ask me how I know. solved my shift problems instantly.

 

[asg13]

so remove the tee, the suction should be on the removed hose correct? If suction, then the vacuum pump is the problem, correct?

Thanks

 

[asg13]

Ok...Put my finger over the rubber hose connected to the vacuum pump after removing the tee...their is suction. Not sure how much is good however..When placing my finger over the hole, upon removing I get s slight popping whistle sound..but definitely a noticeable amount...

Does this leave the REGULATOR as the source?

Hate to change a ton of parts and not get to the source. Mayb I should just take it to a mechanic?

 

[doghead]

That, or follow the TM instructions in the troubleshooting section of the -20TM.

 

[roveroverme]

Ok...Put my finger over the rubber hose connected to the vacuum pump after removing the tee...their is suction. Not sure how much is good however..When placing my finger over the hole, upon removing I get s slight popping whistle sound..but definitely a noticeable amount...

Does this leave the REGULATOR as the source?

Hate to change a ton of parts and not get to the source. Mayb I should just take it to a mechanic?

since the pump hasn't failed. I would suggest to get a vacuum gauge and go through the steps of the TM