Vacuum regulator valve - sources? Replacements? Rebuilding?

[GeneralDisorder]

I got this M1009 unit running and first drive - no shift out of 1st gear. Got 20" of vacuum from the pump. Nothing from the regulator valve. I took it apart and cleaned it up - did get it to function at least a little bit by unscrewing the top to put more tension on the spring inside. Got it into second gear if I lift the throttle.... Looks like the springs have seen better days inside the valve.

Also appears they are discontinued. I did order a NOS one from ebay. Don't like that I can't fix it without a discontinued plastic whackadoodle that some drunken engineer designed to cobble a gas transmission to a diesel with no throttle plate......

Anyone experiment with rebuilding? What about alternate parts or some other control mechanism for the vacuum modulator?

Also - I see people have had success in bypassing them entirely but when I tried that it seemed like the trans went into 2nd when stopped at idle. Wasn't happy about starting up a hill. But it did move. I'm wondering if I may also have a vacuum modulator issue in addition to the valve.

Bueller?

 

[Barrman]

replacing the modulator on the side of the transmission with one that is adjustable works well when the IP mounted valve is bypassed. However, try adjusting the one you have. As in all the way forward, test drive. All the way back, test drive. Adjust to what you want. If no difference, then obviously, your fix didn’t work. If you get the 1-2 shift below 20 mph with very partial throttle and the 2-3 shift around 35 mph then you got it as good as it will ever get.

 

[GeneralDisorder]

Thanks for the tips!

The modulator on the transmission looks to have a small threaded grub screw in the end of it - is that the adjustable unit? This truck has only 8k miles on it but seems to have been messed with by complete idiots that couldn't get it to run or drive correctly so they have touched a bunch of stuff they probably didn't need to touch.

Also ran across this page about a gentleman's (super human) effort to replicate the (almost identical) vacuum regulating valve used in the IDI 7.3 found in the older Ford trucks. I'm thinking of contacting him:

New ‘IDI-Online’ C6 VRV (Vacuum Regulator Valve) - IDI Online

We have new or already-rebuilt replacement C6 IDI VRV's (Vacuum Regulator Valves) for sale. Also, we can rebuild your existing VRV if it is not working or broken. Since the IDI C6 VRV (Vacuum Regulator Valve) was discontinued years ago, they are becoming scarcer and scarcer. We have manufactured...

www.nickpisca.com

 

[Barrman]

Yes, that screw inside it what you adjust it with.

 

[GeneralDisorder]

Yes, that screw inside it what you adjust it with.

The one on the truck looks like it's original and has the "adjustment" on the end - like this one listed on ebay:

Cadillac Chevy vacuum modulator 400 turbo NOS USA | eBay

<p dir="ltr" style="margin-top:0; margin-bottom:0;">Cadillac 1964 Chevrolet 400 turbo vacuum modulator brand new NOS Delco</p> <p dir="ltr" style="margin-top:0; margin-bottom:0;"> Free shipping USA</p>

www.ebay.com

What effect will adjusting this have? Should I tighten or loosen it?

The bulk of my transmission experience is 700R4's and 4L60/80E's so I'm not clear on exactly which way I should adjust this guy if at all.