Trans Modualtors

[phat46]

I'm having trouble making a C-6 shift. I bent the original modulator when the trans was out of the donor vehicle and replaced it with a new one. The new one has the screw adjustment in the end of it. When i first installed it the trans would shift to second, but rather reluctently and very late. Who knows which way to turn the adjustment screw, in or out, to make it shift earlier? It's under a really low vehicle, in a hard to reach area, so I'd like to make as few trips under there as possible....

[Leon]

This is from TCI's site
"By turning the adjusting screw (found in the vacuum nipple) counterclockwise, you will lower the spring pre-load. This will cause earlier shifts. By turning the adjusting screw clockwise and raising the spring pre-load, the shift points will go up. The range of adjustability is only a few mph either way."

[phat46]

This is from TCI's site
"By turning the adjusting screw (found in the vacuum nipple) counterclockwise, you will lower the spring pre-load. This will cause earlier shifts. By turning the adjusting screw clockwise and raising the spring pre-load, the shift points will go up. The range of adjustability is only a few mph either way."

Thanks, I'll try that direction first, It's a hassle to get this thing up in the air enough to get under, so the fewer trips the better...

[Crosley.In.AZ]

a little deeper into this;

is this a thread in modulator or push in type?

Push in type;  Purple stripe around the main cannister of the unit?

[phat46]

a little deeper into this;

is this a thread in modulator or push in type?

Push in type;  Purple stripe around the main cannister of the unit?

This is a thread in type. the old (original) one was painted, so I couldn't tell a color stripe on it. The new one has no stripe.  I'm not sure of the year of the trans, it's behind a '70 429, but it all came out of a '79 Ford truck. The auto parts stores around here looked at me like a monkey looking at a wristwatch when i asked about the C-6 modulator and the color stripes on them. The blister-pack stores couldn't help at all; wasn't on their computers; they could call a rep the next day, etc. finally found one at a local place, but even their books weren't very helpfull. For as much as I know about these things this could be a modulator for a Chevy!!! Ona related note: is the vacuum from the base of the carb enough for the modulator on a C-6? I can change it to direct manifold vac, but it'd take a weird fitting or a bushing.

[Crosley.In.AZ]

there is only one aftermarket thread in modulator available that I know of.

make sure the mod is receiving direct manny fold vacuum from the intake manny fold. Be that from the carb fitting or the manny fold .

back out the adjustment screw 2 turns to see a change you will notice.

You did reinstall the mod pin/rod that is between the internal valve and the vacuum modulator?

[phat46]

there is only one aftermarket thread in modulator available that I know of.

make sure the mod is receiving direct manny fold vacuum from the intake manny fold. Be that from the carb fitting or the manny fold .

back out the adjustment screw 2 turns to see a change you will notice.

You did reinstall the mod pin/rod that is between the internal valve and the vacuum modulator?

Yes, I did reinstall the pin, and that's about how far i turned out the screw after the earlier reply. i will see how it shifts tomorrow. Thanks