M1009 transmission not working properly

[ryan77]

I had a bad vac pump on my blazer with same problems as yours and i couldnt manually shift it! New vac pump problem solved !!

 

[5moker]

Thanks Ryan! My pump feels weak I think (having nothing to compare it too). Pulled the line off while engine was running and heard no vaccum. Stuck it to my finger but barely. Just starting to run low on funds for this project after motor, batteries, paint, ect., ect., ect.

 

[ryan77]

Hook a vac gauge to the pump to verify its bad!

 

[5moker]

Next step! Thanks again. Going to tm's to see if I can find what it should read. Don't have one on hand. Hoping autozone has a loaner. Just felt it again there is something there just don't know how much. Big help Ryan! Just knowing the vaccum pump can cause my problems. Maybe I can sleep now... Been working on this truck every waking hour when I am not at work! Vaccum pump sounds alot easier than trans rebuild!

 

[cliffyp]

Vacuum or governor, independent of each other, they can both cause loss of up shift. Sounds like you might have vacuum issues. If that path leads no where, don't forget to check your governor.

 

[5moker]

Thanks cliffyp. Yes that is scondary to a vaccum pump test. Got both in mind. I;m going to try to run a pump test tomorrow. Can't wait to title this thing and DRIVE it. Anxiety is killing me. I get a little closer and have another hiccup! I see you have 700r4 listed. Where did you get a detent cable bracket? If I have to pull this th400 I will look into a 700r4 (built-up of course).

 

[cliffyp]

The throttle valve cable for the 6.2/700r4 can be hard to find. I was looking for a while. One turned up on that auction site and I hit buy it now. People find them at junk yards too.
There is a member here on SS that was talking about having a machine shop make them if there was enough interest. I don't know what came of that, but if you search for his thread you could see if he has any.

 

[5moker]

I figured... I have a junk yard about 35 miles from me full of 80's model chevys. I have been through there 100 times and don't recall seeing any diesel motors. I am planning a trip up there soon and will be on the look out now. I tell ya a junkyard full of chevys is my heaven. I can get lost for hours. I found one in AL where I got my engine full of mvs. From the 6+6 chevy trucks to generators and tent buildings full of everything you can imagine. I can make a call and have about anything in 3 days! Bent my dipstick tube putting the new motor in at night,and got so irritated I just quit. Left my tools out and all-just had to walk away. It was the Breaking point! The next morning made a call-"$20 in todays mail" was the response on the line! I told her to keep my card on file! THey have at least 10 ACRES of military surplus vehicles and other stuff. Granted they won't have a detent bracket, civy console, ect.,so a trip to my local old chevy yard is in the works.

 

[cliffyp]

Just to clarify:
I said throttle valve cable, but I was talking about the bracket for the cable, not the actual cable. The TV cable is easy, the bracket is hard.

 

[5moker]

I overlooked it! hahaha! Yes I know we were talking about the bracket. I wonder if edelbrock does one??? I know they make unusaul brakets like a throttle and kick down/tv cable barcket for installing a carb on newer vortec engines (Gasoline). I have a lot of chevy experiance. All the th400 trans that i have ran will shift fist to second if you pull the shifter in first and leave it there. It will shift high rpms HARD. with a good motor it feels like someone hit the back of your seat with a hammer! I am in paint mode this week, then I will go back to trans... Now that I have a good Idea of where to go next.

 

[gebirgsoldat]

I'm having similar issues with my 86 CUCV Blazer.. the vacuum pump needs replacing.. does anyone have part no.s or know where I can locate one (NOS)?

 

[rickf]

I have not seen one reference to the vacuum modulator. They do go bad and will cause the no upshift issues that are being mentioned.

 

[cpf240]

It is a good idea to test the vacuum pump with a vacuum gauge before assuming it is bad. The vacuum switch on the side of the IP can also be tested with the vacuum gauge. This should narrow down the problem pretty quickly, assuming it is related to the vacuum system.

 

[gebirgsoldat]

That's all been checked by a good diesel mechanic it has low pressure, and adjustment hasn't worked out.. NOW I Just need to replace it...

 

[gafuller01]

Ok, I rebuilt the transmission and finally got it put back in. After adjusting the linkages and the vacuum modulator the truck runs great in all forward gears. Shifts quick and hard, but not too hard. Downshifts with electric kickdown. I can engine brake by manually downshifting. I still have a problem though. The truck does not reverse very well. It will reverse, but I have to give it a fair amount of throttle, and it kicks and jerks the whole time. Does anyone have any idea what would cause this. I sure hope the fix won't require another full teardown.