My early '65 Mustang has a c4 automatic transmission. I just had some work done fixing the leaks (kick down and pan gasket) and now it won't shift into third. 1st and 2nd work fine, even the kick down can bump it back to first gear. It won't shift to 3rd under any cirmcumstance. So I did check the kick down rod, and it is not activated.

I've read through some other threads, but not one specifically like this. Some people mentioned vacuum hoses but I'm not sure where they should actually connect. Can somebody give me some pointers? I reckon I'll be visiting the mechanic again, but if it's something simple likea hose I'd take care of it. Thanks!

 

i know this sounds condescending ... did you check tranny fluid level?
at the same time I cannot see how kickdown could have affect on this, unless the kickdown is activated the whole time ?!

 

I had the same problem where the tranny wouldn't shift into 3rd gear. I traced the vacuum line and it was not attached. I reattached it and the car shifted into 3rd without any more problems. The modulator is located on the transmission shaped like a cannister with a hose/line coming out of it. You can trace it up to where i picks up its source of vaccum, usually a metal line up towards the firewall. Good Luck!!!

 

It could be out of adjustment
3rd gear could be ground to dust too

I have had both of those cause it not to shift into 3rd

 

Thanks for all the ideas. It'll probably be tomorrow night before I can trace the vacuum line. I took a glance and saw the line was there at least. That's fine asking about the tranny fluid, never can know what somebody has checked. The fluid level is fine though.

That's actually why I got it worked on in the first place. It was leaking about a quart a week. So I had the experience with no gear and low fluid. Don't worry, not trying to drive it, just moving it in and out of the carport. BUT, 3rd gear was working since I went up the hill and back a couple times.

I checked the kickdown since somebody suggested maybe it was stuck. So, I hope it's something simple since it was working recently. I guess I'll check moreout tomorrow...

 

if everything else is ok then I 2nd the vacuum modulator. It it is hooked up then it would be the first thing to replace because it is the cheapest part (20-30 bucks) instead of the rebuild.

good luck

 

Eh, only had a few minutes to look over the tranny. I'll plan on finding a modulator and seeing if that works. But it is hooked up with a hose to a metal line, which if I followed it right leads up to the back of the intake manifold. We'll see what a new modulator does...

 

I had 3rd gear burn up due to a shift cable that became melted by the transmission. When the cable melted it didnt properly engage 3rd gear by the time i notice the cable was melted it was too late. The gear is either burned up or its not... its not going to be partly functional... no weekend warriors here.
Im not sure if your running a shift cable or not. But improper engagement is still a possibility due to an adjustment issue.

happy hunting

Gun

 

Well, I had trouble with the gas tank leaking, hopefully got that fixed. Just got to test run it again. Unless I'm crazy it went through 1st, 2nd, and 3rd gear about 3 times before it quit. I bought the modulator but can't get the old one off since the tranny pan is sticking out a little in the way. Sheesh. Might just take some vice grips to it.