Ok so I checked the modulator and yes it has the push rod and the throttle vavle but not too sure on how you say the throttle valve should be put it and the push rod goes in it...? so I can make sure it was in the right way or wrong way.
View image in galleryis this the way the throttle valve should face for the push rod to go in or should i flip it the other way...?
I am thinking the throttle valve should be flipped around, with the hour-glass end closest to the modulator, but I'll check mine when I get home from work and post back here. Mine is sitting on the bench, so it's easy to get to, and has never been apart, so I know it's correct in there.
I'm thinking I may have the wrong modulator I believe I bought the one for $19.99 or the BWD one for $37.99 says it model XP transmission (?) not sure what that means but, I believe I need the PowerTorque one that's $23.99? What would you say? Sorry i posted the link next page...
http://www.oreillyauto.com/site/c/search/Transmission+Parts/C0073/C0338.oap?year=1977&make=Ford&model=Mustang%2BII&vi=1134694&keyword=vacuum+modulator&cat=AT+Modulator
http://www.performanceautomatic.com/products/parts-and-accessories/service-parts/c4-service-parts/c4-service-parts.html According to PA website I need a yellow stripe modulator? ( scroll almost half way down its vacuum modulator #38 is what they say for 74 and up and I have a 77 valve body not sure if its the same for the transmission casing)
THIS ^^^ is the correct configuration. I checked mine last night and it's the same. I doubt that the wrong type of modulator would give you the problems you're experiencing. It would shift at different points, but it would shift eventually. Just my own thoughts, though...I could be wrong. I'm just about tapped-out as far as my knowledge of transmissions. RE: The PA website saying yours should be #38. I don't think that is correct either. The #38 on the list says it's a screw-in type, but yours is the push-in type.
Thanks Paul for the info, diagrams and all your help I will dig the web some more and put it back together and when I get the money for some tranny fluid I'll post back with results but as I did the web I'll post with info I find. Thanks again for all the help.
Good luck, man. Have you thought about taking your little flat mystery piece to a local transmission shop to ask someone what it could be? I'm surprised nobody here has jumped in with suggestions. Paul S was the in-house transmission guru here on this site, but I believe health issues have made him scarce around here. Have you tried searching the Transmission forum here for keywords or other similar problems? Let us know how you make out. If I can think of anything else to check, I'll post here.
Thanks Paul, and yea I took to a guy they say is the best in town and he wasn't sure he believed it probably had something to do with maybe a shift kit he didn't think it was a piece that fell out of the actual tranny but I'm not sure if it has a shift kit I did realize that some springs and check balls were missing like you would do for a shift kit but it didnt look to me as if the spacer plate holes had been drilled bigger like you do for a shift kit. But I checked all shift kits and didn't see where a flat piece of metal was used?
Mine did the same thing right after a rebuild. Took it back to the shop and they fixed it. Said they accidentally left a check ball out.
mine has all the check balls its suppose to have I have checked diagrams and I actually have the how to rebuild and modify a c4 and c6 transmission book by SA Design and according to it all the check balls are there except the one you can remove when doing a shift kit install. P.S What is best to use to clean both halfs of my valve body... would kerosene, gas or diesel work good?
I was reading an archived technical article written by Paul S. where he talks about making a small restrictor for a C4 valve body modification...... http://mmb.maverick.to/showthread.php?t=35487 Thread #4 "From a piece of cold rolled flat bar 1/10" thick and 3/4" wide cut a piece just over 3/16" long. File both of the longest sides on its edge until you have a finished piece 1/10" x .188" x 3/4". You are only filing the edge you cut and it's opposite edge. DO NOT make it thinner than 1/10" and you want it every bit of 3/4" long. This is the restrictor that you will put in the channel casting and separator plate. It will stick up through the slot you marked in the separator plate earlier." Could this be the mystery piece?
I did notice it was sticking up but didn't think it would fall out so i didn't take note of it and when I took valve body apart it fell out and I looked and looked for somewhere it could possibly go but make out anywhere so then I got to thinking maybe it fell out of the tranny case and got wedged in the valve body but a local tranny shop said that wasn't the case. So I'll def check into to what your saying cause that makes sense I do recall it sticking up out the top of valve body.
