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Long post with backstory, hopefully someone can provide some insight:

Have a 1967 GTO with an M21 and a hurst shifter. We recently got the car back on the road after spinning a rod bearing. Car sat for three years waiting for our mechanic to get excited about rebuilding the 400.....

Anyway, one of the things I've noticed now that we're putting some miles on it is how stiff everything is. Clutch feels different with a shorter contact patch, brakes need to be bled/inspected, etc. One thing that was incredibly apparent was how difficult it was to shift between gears, especially getting the shifter over into reverse. I had to lean on the shifter just to get it to come over to reverse, and the effort between gears was substantial.

And one day, going into reverse, something clicked/snapped, and now the shifter is all over the place. Does this sounds like it's as simple as shifter bushings, or could it be a bigger project? I will be able to get the car on the lift this weekend, what should I be looking for specifically?
 

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I assume " Clutch feels different with a shorter contact patch" means that the pedal grabs closer to the floor? It is possible that the clutch linkage has been incorrectly adjusted. This could also mean that your short pedal throw was not completely disengaging the clutch - which can cause shift related problems like not being able to get the shifter in gear cleanly. That is my first observation, but it my not be a related problem or it could be.

"now the shifter is all over the place" is a broad statement. Does it work? Is it flopping all over and not going into any gear? Is it sloppy left to right or front to back?

Hearing something snap is not good. Did the shifter handle break off? Next thing might be the bolts that bolt to the shifter plate which in turn bolts to the transmission may have backed out or snapped. It is also possible the shifter plate itself has come loose from the transmission or has broken off. Both of these would make the shifter feel "all over the place."

Bushings would tighten up a sloppy shifter, but it would still operate, just have a lot of play. If a rod fell off, then you would lose that gear, but that would be obvious.

So definitely need to get it up on a lift to take a look to see what is happening. I would also get the clutch pedal adjusted to ensure that it is releasing the clutch. With someone pushing in the clutch, a feeler gauge can be used between the disc and pressure plate.

Your mechanic most likely had to drop the trans to remove the engine for rebuild. This would have also included removing the shifter. Did the mechanic use a pin to align the shifting arms within the shifter itself and then adjust the linkages to the transmission? If this is not done, then this will cause misalignment within the shifter and you may experience the symptoms you had with reverse.
 

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Discussion Starter #3
I assume " Clutch feels different with a shorter contact patch" means that the pedal grabs closer to the floor? It is possible that the clutch linkage has been incorrectly adjusted. This could also mean that your short pedal throw was not completely disengaging the clutch - which can cause shift related problems like not being able to get the shifter in gear cleanly. That is my first observation, but it my not be a related problem or it could be.

"now the shifter is all over the place" is a broad statement. Does it work? Is it flopping all over and not going into any gear? Is it sloppy left to right or front to back?

Hearing something snap is not good. Did the shifter handle break off? Next thing might be the bolts that bolt to the shifter plate which in turn bolts to the transmission may have backed out or snapped. It is also possible the shifter plate itself has come loose from the transmission or has broken off. Both of these would make the shifter feel "all over the place."

Bushings would tighten up a sloppy shifter, but it would still operate, just have a lot of play. If a rod fell off, then you would lose that gear, but that would be obvious.

So definitely need to get it up on a lift to take a look to see what is happening. I would also get the clutch pedal adjusted to ensure that it is releasing the clutch. With someone pushing in the clutch, a feeler gauge can be used between the disc and pressure plate.

Your mechanic most likely had to drop the trans to remove the engine for rebuild. This would have also included removing the shifter. Did the mechanic use a pin to align the shifting arms within the shifter itself and then adjust the linkages to the transmission? If this is not done, then this will cause misalignment within the shifter and you may experience the symptoms you had with reverse.
Thanks for the response

With regards to the clutch - contact patch is at the opposite end of the travel, very high. I just remember it being more so in the middle of the pedal travel. The clutch definitely fully disengages the gears.

So, when I say "all over the place" I mean that before the rebuild, you could easily tell what gear you were shifting into. The shifter rested on the 3-4 side and you pulled it over to the 1-2 side, almost like there were "gates" you were moving it toward. Reverse had a pronounced throw, but there was resistance into that throw.

Now, when the shifter is out of gear, there's no "gate" feel, if that makes sense. Very loose in between gears. It still engages the gears properly, so we definitely didn't lose a rod. BUT there is no resistance as to where it rests and it if very difficult to figure out where you are.

This weekend I will pull the center console and inspect the mounting plate and shifter, and get underneath to inspect the rods and bushings. Hopefully it is not a broken bolt or mounting issue.
 

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KP: With regards to the clutch - contact patch is at the opposite end of the travel, very high. I just remember it being more so in the middle of the pedal travel. The clutch definitely fully disengages the gears."

PJ: OK, to adjust, there is a rod coming off your Z-bar that goes to the clutch fork. It will either have two nuts and a slip joint, or threaded end. This is where you will adjust the clutch/pedal travel. I like my pedal more in the 1/2 to 3/4 travel range - as long as I am getting a clean shift. Don't like them right off the floor or near the top.

KP: "get underneath to inspect the rods and bushings."

PJ: Right from the Hurst website, "What is the proper way to adjust my Hurst four speed shifter? There is a 1/4 inch hole at the bottom of the Hurst mechanism that runs through all three levers. This is called the neutral alignment hole. To ensure proper adjustment, run the shifter from first into second and then back to neutral. Insert the neutral alignment pin (or a 1/4 inch drill bit) into the neutral alignment hole. If the 1-2 lever interferes with the smooth insertion of the alignment pin, remove the 1-2 linkage rod from the shifter and thread the adjuster button either in or out to eliminate the interference. Repeat this procedure with the 3-4 lever and reverse. To adjust the stop bolts, back the bolts out of the shifter frame until only a few threads remain. Push the stick firmly into third gear and hold. Screw in the stop bolt until contact is made. Release the stick and back the stop bolt out one turn and tighten the jamnut. Push the stick into fourth gear and repeat the procedure.

KP: "there's no "gate" feel,"

PJ: There are a few springs in the shifter. It could have been one of these that snapped and is the cause of the sloppy feeling shifter. Check this out, might be worth trying your hand at rebuilding the shifter yourself: https://www.hurstshiftersonline.com/productcart/pc/Hurst-Service-Parts-Mechanism-Parts-c53.htm?pageStyle=h&ProdSort=0&page=8&idCategory=53
 
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