Dave WM

That is one clean cylinder head! I thought of a good test procedure regarding the use of the Z shifter in a ZX 5 speed. Best done with the transmission on the bench. Shift trans into 5th gear carefully remove the shift pin and remove the shifter see if there is any binding against the oval shaped hole in the strike rod head. Use a tool (large screwdriver) to see if the shift head can be moved any further rearward (this would be proof the engagement was not complete) check to see if it seems to be in the detent position. put the shifter back in with the pin in place see if there is any resistance felt, if so grind away the metal that is coming into contact. Do the same for the reverse gear. Some bluing or finger nail polish on the shifter may make it easier to see where the contact is happening. The metal of the shifter is pretty soft, easy to remove with a dremal moto tool and drum sander. I wish I had tried this before doing grinding. For now I am using a thin paper strip inserted into the oval opening where the binding can take place. My reverse is still just a tad tight (tore the paper). So I will get the witness paint on the shifter to see if I can locate the exact spot to be ground.

go for it, be a menace to society!

interesting I did the same measurement (nut to fork) and only came up with 49mm, but the fork looks like a 90 to the housing. Will double check but 10mm seems like a big difference esp if the forks are in the same approx. position. I feel a mystery coming on, gotta think like Lt. Columbo and tie up some loose ends. I guess given the mechanical advantage the fork provides, even small variation is clutch plate thickness could cause sizable variation of the fork position (at rest, pedal NOT pressed down).

yea I may have added to the confusion, the OP was talking about a 77 Z 5speed, I have a 81 ZX 5 speed and have been talking about my exp with it.

Note when he removes the outer bearing races he says chisel, but uses a punch. I would not want to be banging a chisel inside the wheel hub and risk gouging something. I would use a soft metal like a brass drift to punch with or a regular steel punch but with care to only got on the lip of the race. Same guy has a good video on L engine valve adjustment.

The design looks to me to be an attempt to allow the bearing cup on the end of the shifter to move in a more lateral motion to stay fully engaged in the shift rod head. The fixed pivot point of the Z shifter the bearing cup will move in an arc line, slightly pulling away from the shift rod head when not in neutral. I would have assumed this was accounted for in the design of the orig shifter and not have been enough to cause a problem. The movable pivot point on the latter resolves this by extending the radius line as it moves off neutral, but I would think at the same time in introduces more plastic wear surface into the entire mechanism, fine in the short run but likely to get loose with a lot of use. Engineers love to change things (star trek the motion picture).

I feel success is just around the corner!

the dia of the shaft looks noticeably smaller on the ZX shifter, try measuring up from the bottom to the marks and get a dia there, then do the same on the ZX shifter. On my ZX trans the rev idler gear was pretty chewed up. I noticed when the trans was apart that even when fully engaged the rev idler was only about 70% at best in mesh with the main shaft straight cut gear. I also noticed that the rev position of the shifter was the worst position for the clearance issue (marks). I wonder if when shifting the reverse gear was even less engaged than the amount noted when I had it apart? Anyway I have ground it such that I can fully engage reverse now as well with a tiny bit of play left after the detents take over.

ok I get it completely now, saw the same marks, used a dermal drum sander to reshape along the problem areas. Remove a little bit go check do again. Now I can shift and clearly see the detents are locking in before the shifter comes into contact with the oval hole on the striker rod head (that is where the marks come from. Glad I did this before installing, its much easier to see what happening with a bright light and getting close in.

is it possible you have a different spline count on the clutch disk?

I looked at mine I just cant see how it could possibly hit anything. I will get a video up later to try and clarify. I assume the interference is with the transmission and NOT the car tunnel? based on where the grind marks it would be pretty deep in the shift part (cast iron part). I don't see how a different length would even work unless the short one is just barely catching the shift rod while the long one fully seats. Ok checked 1.75 or 1 3/4 inch.

I am going to go take a close look at mine today and see if I can see any marks on the shifter (before I try to install the trans).

My plan was to use a hyd floor jack with straps and what ever it takes to secure it to the jack (maybe a custom ply wood square with a solid attachment to the jack). I just popped for some massive jack stands that should give me a LOT of clearance. I know about cramping in tight quarters, I have the same problem. Drink some gator aide, you may be dehydrated ( a common problem for us in the tropics). Staying safe is number one, no good getting the car done but being laid up and cant enjoy it.

got the HF 12 tons, WOW these things look like they could support an M-1 Tank. really overkill (hmm odd use of a term) but I will feel much better under the car with them. They have a very wide stance (no jokes pls) and are VERY heavy. I only got a single pair will go back and get the other next week. the min height is approx. 19" so pretty darn high to start with, can go up to 30" which if I had a jack that could get that high would be great. I have several task to accomplish starting with Tank filler neck replacement (have a refurbished one to replace the rusting on Tank sending unit O ring seal (leaking) Rear Diff gear oil change (have no idea when it was last serviced, have some MT 80-140 IIRC for it. that should cover the rear, next up will be to remove the exhaust so I can get a the trans for a swap (4 to 5 speed zx close ratio) I would like to do something with all the heat shields on the exhaust (CA car with cat and shields all over the place). Just not sure what to do.

Saved me again, after reading this I went out and looked at mine, not only did I not use any sealant on the thread, but I had only installed it finger tight!

I would be real tempted to futz around with that alignment tool just to see how easy it goes in then. Also don't know about yours but my input shaft has a tiny bit of play in it. I figure this is normal considering how its supported ( a single needle bearing and input shaft bearing with a fairly long input shaft to multiply the play). I assume this is why you have to "finesse" the shaft into the pilot bushing. Maybe some measurement from the bolt holes to the side of the centered up alignment tool? compare the trans just to make sure you are in the ball park? Of course my suggestions are from someone that has never done this, but really just thinking out loud. Really pulling for you since I am in the same boat and want to see some success!

Really like the progress you are making, its making me think I will use the existing pressure plate/clutch on mine when I do the swap. I know its a good time to replace the clutch, but I really like the idea of only making one change at a time. I have learned this process working on old electronics. If you are experienced you can make multiple fixes and trouble shoot if an issue arises. Newbs can run into trouble since it can be hard to determine what's wrong if multiple fixes are done and then there is a problem. Yes its more work (as I will likely have to replace the clutch later) BUT since I am really doing this as a hobby, and not paying for the time (not going with the rent a bay, just got some 12 ton jack stands), it's ok to be wasteful of time. BTW the Jacks are MASSIVE I mean HUGE 20" min high and 12*12 base makes me feel like I will not worry about it. Its getting busy at work for me now so I am going slow but will get there. Good work, more pics and video if you can please.

yep State bird in Florida IIRC, Very cool bird, with its singing abilities. I am going to practice using the nut splitter to get the feel of it.

I had a pretty good day at the yard today. I found a 90 degree check valve of the same size and material (brass) that came with the replacement booster (it was straight out the back which did not work well when the outlet was on the opposite side making the factory hose not workable. Also found a hose that works well with the new fitting for a factory look. will post up some videos later. Will hang on to the orig hose in case there is ever a need to return to the orig setup (the car is pretty much a survivor but for the masters and clutch slave).

are you having any clearance issues with the shifter? maybe not going all the way into 5th?

Well it seems the only problem with the old booster was a leaking output rod shaft seal. I have no idea how to find the correct pn to replace it. I would like to keep the orig booster and fix it.

Brake booster developed a leak, got a replacement from auto zone (video later) odd thing was I had to install it upside down (the booster port was low and on fender side, now its high and on the engine side), for the holes to line up on the fire wall. There is a slight offset on the fire wall side between the 4 mount lugs and the main pushrod that goes to the pedal. Just wondering if anyone else noticed this? It was a 88031 IIRC booster from power brake exchange.