1984 Chevrolet CUC/V M1009 K5 Blazer (The Mule)

[cucvrus]

I have a question about the VCV on the injection pump of my M1009. Last week I had short shifts in drive by 20 MPH. I went to the parts store and replaced all of the vacuum hoses top and bottom. Still the same. I purchased a new modulator at Auto zone and now it shifts late. And it hangs in 2nd till 50. And I mean hangs in 2nd. I disconnected the pass switch on the fuel pedal inside. No fix. I then adjusted the VCV valve several times no change. I then hooked the line from the vacuum pump directly to the metal line going to the modulator. Now the truck shifts fine. Will it do damage to the tranmission if I leave it this way? And also can the VCV be taken apart and rebuilt. I am sorry if I am bringing up a subject that has already been covered. But if someone could direct me in the right direction i will go from there. Thank you.

 

[Warthog]

The tech manual has a great step by step to test and adjust the VCV

 

[cucvrus]

At this time I have adjusted the VCV to no avail. I would like to know if harm is being done to the transmission if it is driven this way. I will look into changing the VCV when time allows. I have a new GM one. But for a few days I have been driving it hooked directly to the modulator. Will that hurt the transmission in any way? Also I know I saw a post on SS about the ease of setting these in the past. Do you recall the post that I can find this information? Something like moving the VCV toward the firewall makes the shifts do 1 thing and towards the radiator does another thing. If you recall that post I would like to know that information. Because I also recall that they were discussing the rebuilding of the VCV. I would rather repair then replace the valve. As long as it is repairable. I like to keep my new OEM parts until all else fails. They are hard to come by. Any Help?

 

[Warthog]

http://www.steelsoldiers.com/showthread.php?50568-CUCV-Throttle-Vacuum-Valve-Adjustment

I do not believe the valve is rebuildable. The plastic is fused together.

 

[cucvrus]

Thank you. That was the information I was looking for. Will driving it hooked up directly from the vacuum pump to the modilator damage the transmission in any way? And how do you post pictures of your CUC/V on this site?

 

[Warthog]

The tranmission is designed to shift at around 8" of vacuum. That is about half throttle of gasser engine. Since diesels do not produce a vacuum like a gasser engine, they install a vacuum pump and the throttle valve to simulate the gasser vacuum.

If your vacuum pump is functioning properly, it will be providing 20" of vacuum to the modulator all the time. The transmission will not know when to shift correctly.

Will it break anything? Who knows, but it really isn't good for it.

Here is the picture posting tutorial

http://www.steelsoldiers.com/showthread.php?59917-How-to-post-pictures-a-tutorial

 

[cucvrus]

I will be on it as soon as I am able to do so. For now it shifts fine and the kick down is electric and that still works fine. I know they put the VCV there for a reason but I do not want to damage the transmission just to avoid replacing the VCV. I am surprised at how nice it does shift. I would never know that anything was not hooked up properly if I did not see and know it. I have bought some CUC/V's that had no vacuum and they shift with neck snapping speed. This is not the case. It shifts smoothly and at the right time. A mechanic told me it was the governor in the trans. I don't think that is the case. But maybe. I will let you all know. How can I post some pictures on the site?

 

[Warthog]

How can I post some pictures on the site?

Here is the picture posting tutorial


http://www.steelsoldiers.com/showthread.php?59917-How-to-post-pictures-a-tutorial

 

[cucvrus]

I can't find that screen. Manage attachments????

 

[Warthog]

Start reading at post #33. It says that in bold letters in the first post.

 

[cucvrus]

I give up at this point on posting pictures. I will keep my pictures until I get someone else that can post them. I can not get anything up on screen that is the same as the tutorial. (Manage attachments) Sorry.

 

[MarcusOReallyus]

When you hit 'Reply' or 'Post New Thread', look down the page. It's there.

 

[cucvrus]

1984 Chevrolet M1009 The Mule

When you hit 'Reply' or 'Post New Thread', look down the page. It's there.

 

[cucvrus]

I purchased this vehicle 8 years ago at a scrap sale. It was missing the tires, wheels ,radiator, alternators. starter, seats, and injection pump. It was pushed around with a loader several times it had another M1009 stacked on top of it in the same condition. It amazed me that when I bought 4 of them in the same condition that 3 of the 4 ran. I removed the broken roof and cut it down to fit the lower part of the cab floor. I took a front bed wall from a M1008 and attached it to the sides and floor of the M1009. I then took a bench seat and attached it in the cab. I bought a HMMWV canvas top and cut it down to fit my new design. I removed the M1009 tailgate and used all the attaching hardware for the pickup and bolted it all up. I also made a set of short troop seats that attached via the M1009 rear gate striker bolts and the front side roof bolts. They were a rattle issue and someone else wanted them bad enough and offered me a fair price for them. You guessed it a new owner. It has current PA title and everything works well. Not much to go wrong. No radio it is as is from the factory inside with exception of LED overhead lighting and under dash LED lighting. The grille is the original grille I milled it out for the quad headlamp turn signal lamps so I could mount the Bosch driving lamps in the OEM park turn lamp position. I hope you like the pictures. I enjoy driving it when ever and where ever I can. I have several CUC/V vehicles that I will post at a later date. Sorry for any issues I caused with the miss placed photos.

 

[Warthog]

Good looking truck. Interesting solution for the top.

Where is Jonestown located? Can you update your profile to list your state of residence? Site rules.

 

[Skinny]

I forget which direction to push the VCV but if you flip it in the other direction and it doesn't change the shift pattern more than likely it is defective. I would rule out the governor sticking as you were able to change the shift sequence with a direct vacuum connection.

Realistically, you should be able to dial the VCV in just with a test drive. You can get technical with it but if its not too firm or soft, run with it. Wait...that doesn't sound right