Replaced Clutch, car won't shift into gear



My guess…your new (assume reman) clutch disc is a few thousands too thick. Try starting in 1st and do a half dozen “spirited” take-offs with a few seconds of clutch slippage with each start.


I know this may sound stupid but I have to ask. Is the transmission mating to the engine with no gap? All the way around, top, sides?


Good thinking Keith. A burred mating surface between the bell housing and clock or transmission could cause the problem.

Also, a sprung pressure plate diaphram or a weak/sprung clutch disc segment can cause the problem and be easily overlooked.


The bellhousing and transmission are both snug up into place.

As far as a sprung pressure plate diaphram or a sprung clutch disk I am unsure.

I am just taking it into a shop at some point in time this week. This shop also specializes in transmission work and they are giving me a good deal since we send cars here all the time(I work at an auto collision repair center. But we fix mainly body panels and such. Not mechanical issues.)


When you mounted the pressure plate, did you find it difficult to get the bolts to reach the flywheel because of the gap between the pressure plate and the flywheel?


Not too bad. They screwed in at first, but getting them to fully tighten has been a pain.

Anyways, another detail that I should be mentioning is before the clutch change, it was doing exactly this. The car would only power shift into gear. Just now it is even harder with a fresh clutch to power shift like that. When I pulled the old clutch out, it still had quite a bit of life on the clutch plate. It really didn’t need replaced but I already had a new one. The old throwout bearing on the other hand was in pieces, so that obviously needed replaced.


@rs.lainhart, you remind me of Navy pilots. After a flight, they come through maintenance control, “great jet, no gripes” and then on occasion, the next four words that the Maintenance Chief hates to hear because he knows deep in his gut, that jet’s next trip is to the hanger bay for some all night repairs, “oh by the way”.

So, are there any more “oh by the way” we should know about, like whining noises from the transmission, a little play in the input shaft, play in the pivot point of the clutch fork?


Sorry that you are upset to hear that perhaps I installed a clutch correctly and that you can no longer try and pick on things I could have done wrong. Anyways… Lots of details I have to cover with this. None of your “oh by the way” things are happening, just like all the other ideas you have given have been incorrect as to what is wrong. What a surprise…

What else can I be checking?

Although I appreciate the respectful help I have recieved from those honestly just trying to help me figure out what’s going on. Thank you, I appreciate.


If your reason for replacing the original clutch was the same symptom that you are experiencing with your newly installed clutch the first game is over.

So now, game two begins. The fork and or pivot ball may be worn and/or the fork may be bent.




I am not upset that you are doing things right. If you had mentioned earlier that this issue started before you replaced the clutch, I would have been far less inclined to think that you got something backwards.

You see, in the maintenance world that I come from, if it worked before you “fixed it” and now it doesn’t, you did something wrong. If it was already broken before you started, then you have overlooked something. Your case has just moved to the latter condition.

I believe that you came here for help in finding what got overlooked, but none of us have hands or eyes on your project, so we have to ask questions. Sometimes these questions may seem stupid or insulting, they are not meat to be. But who among us has not overlooked something that was obvious to everyone else?

Sorry you didn’t see the humor in my previous post. Maybe you had to be there to see it. Some examples, “Oh by the way, the stick felt a little loose during landing”. Found the hydraulic system got air in it and the vibrations ripped a big hole in the main bulkhead that the plane is built around.

The best one “Oh by the way, I might have gone over the G limit a little.” Inspection of the hidden tattletale G meter showed 12.5G’s. Five of the six large rivets that hold each wing to the fuselage were cracked or broken.


If the thread had started out saying: I changed (what ever part ) because it was doing (what ever symptom’s or noise ) and it is still doing the same thing a solution might have been reached. Now that the vehicle is going to a shop it would be nice to hear what the problem was.


So it’s in the shop now. They thought that maybe I just put the wrong kind of clutch in so they went and bought a new clutch and put it in. Still nothing. So they are taking it back apart, putting my clutch that I put in back in. And they are pulling the top of the transmission off and having the input shaft inspected on the inside.


The blind leading the blind???

Would any professional posting here ignore the symptom and throw a new clutch at the car without carefully investigating the situation first?


This sounds like insanity at work.


When you press on the clutch pedal a fork-like gadget presses on the throw-out bearing, which in turn pushes sort of in the center of a circular-plate looking gadget with a lot of spring-like arms on it, which causes the arms at the outer end to release the clutch disc from up against the flywheel where it is held by those springy-arms when the pedal isn’t being pressed on. The clutch disc connects solidly to the input shaft of the transmission. So it is sort of like turning a pie plate upside down, pressing down in the center, and the spring effect of the metal pie plate causes the outer edges lift up a little.

That all is not happening correctly in your Mustang for some reason. The pie plat edges aren’t lifting up high enough, which means the clutch disc remains pressed against the flywheel too strongly, preventing you from shifting when the engine is running, or when you start in gear with the clutch pedal pressed, the car moves forward.

So in my pea-brain way of thinking, the problem pretty much has to be from among – in terms of the pie plate analogy –

  • the center of the pie plate isn’t being pressed hard enough, or in the right place; or
  • the pie plate isn’t doing what it is supposed to do when it is pressed on; i.e. lift up the outer edges.

The latter problem happened in a recent episode ( few months ago) in “Hot Rod” magazine’s “Hot Rod to the Rescue” monthly feature, so you might take a look at that. In that case the springy arms just weren’t springing up enough at the outer edge. The repair shop had to bend them a little to make it work correctly.

To the extent you have a custom build going on, which I think you mention may be the case, you’ll probably have to take things apart enough to verify each of the steps above is working correctly. That may mean you have to remove the transmission and clutch and bench test the works until you are certain it works.


I can guess. Maybe the clutch cable support clamp (anchor maybe) was left off or is worn out and loose. Maybe there is more than one.


I have another question. Does this have a dual mass flywheel? If it does, the two parts of the flywheel may have separated and something got in between them.


Was a dual mass flywheel an option on V-6 Ford Mustangs? Or on any domestic automobile for that matter?


Has anyone checked the firewall for cracks or excessive flexing around the cable grommet when the cable pressure is applied? Or the lower end of the cable housing?