Tranny Vacuum Modulator

Are vacuum modulators (push on) for C4 and C6 trannys interchangable?

I was also wondering if anyone knows what each of the colored stripes stands for on various modulators? I think that Red stripe stands for beer! Horrayyyy Beer!

 

Stripes

From what I know (which is very little) The different color stripes indicate different spring tensions in the valve which will cause for earlier/delayed softer/firmer shifts... My 351W with FMX transmission in my Maverick has a blue stripe. Also, if there are two vacuum lines running from it, it's a double diaphram, like mine. If there's only 1, then it's a single.

-Eric

 

Thanks for the reply, I have the single diaphragm modulator. The only ont they had in stock at my local parts store was for a c6 with black stripe. If I remember correctly the one on my mav now is for my c4 with a yellow stripe (diaphragm has leak though) I am trying to figure out how to select a new one since there are so many available.

 

I would get the correct color that came with your car for the C4.


I think the double vaccum line type was used with EGR valves and other emissions set-ups. I had the double but pluged off the reverse side since I did away with the EGR system. I have changed so many variables with my car I have had to readjust mine to shift better because I don't have anywhere near factory vaccum settings. There is adjustment screw on the back of mine. I assume on the single that the vaccum line goes in the back of the unit so if they have an adjustment screw it is probably inside the vaccum port. I am not for sure on that though because I have only recently worked with my double. Anyway with this how I have custom tuned my car to shift better. It was kind of a trial and error thing to get it right but I have a shift kit too so it took me a good half a day but I love the way she shifts.

 

I have plugged the return side also, as I have done away with the EGR as well. I'm still working on modifying a Hurst ProStick2 (that works for C4 and C6) to work with my FMX, so I'm not sure on how she shifts yet, but I'm sure I'll get it lined out....

 

get a c4 push in with a green stripe. it is adjustable to a certain extent by turning the small adj screw inside the vacuum nipple.

 

Which direction to turn for more delay in shifts? Clockwise?

With my new gears it shifts way to soon for me.

 

if i remember correctly, clockwise raises shifts.

 

Are they all the push-in type on these cars? Mine is a '73 and I have never looked at it that closely...

 

I would stick with the color that your car was originally equiped with as long as it is adjustable. If not then try to find an adjsutable one.

The unit has o rings. You push the unit into the casing, it is held there by an bracket. This bracket has a slot for the vaccum line for the single line versions which also serves as way to acess the adjustable screw for both the single and double versions. I still have to loosen the bracket cause it not exactly centered over my adjustment screw in order to get an allen wrench up in there. Make sure you hold onto it if you loosen the bracket, it will turn when you try to adjust you will also loose tranny fluid if it comes out.

To Adjust tighten = quicker shifts. Loosen = slows the shift down. Try going one turn at a time. Make sure your car is warmed up and go test drive. Repeat until your happy with your shift points.

The the more delayed the shift the more wear on the bands.

 

Stripe Color Code

:confused: Does anybody know the secret of the stripe color code? :confused: There are like 6 or 7 different colors offered for the 73 Maverick with C4 in Kragens computer but no info as to what each color is. My car originally had (if I remember correctly) the modulator with a white stripe and single vacuum hose, I later installed a B&M shift kit which had me switch that to one with a yellow stripe single vacuum. Through all of this there has been no indication to what these mysterious stripes stand for. I searched all over the web with no luck other than finding the colors available to buy. Maybe it is just a cosmetic touch so you can see your favorite color while working under your car

 

Modulator Replacement

I KNOW YOU STAY WITH SAME COLOR CODE,AND THE ADJ IS COUNTER CLOCK TO SHIFT FASTER. WHAT I DONT KNOW ARE THE STEPS WE MUST TAKE TOO CHANGE IT OUT.............ANY ANSWERS OUT THERE .PLEASE

 

ok..

let me get this straight..

if i want the tranny to shift at higher rpms.. as in lets say now it shifts at 2500 rpms.. but i want it to shift at 3500 rpms, then i turn the screw clockwise

 

That Is The Way I Understand It Too Be.

 

And I Am Going Too Lift The Tran To Change Out The Modulator