Mark Maras

The "divot" is common in old cylinders. If the seals won't contact it during their stroke and if you can get an installed seal past the divot without damaging it, IMO you're good to go. I'd consider the repair as a temp and give me time to source a new one. What is the difference between the old and new seals?

I discovered the lack of height to clear the bellhousing the first time too. I separated the bellhousing from the trans under the car (early trans) and reassembled it under the car. It was easier than lifting the car higher at that time. That was also back in 75. Now my back is the reason I don't.

Has anyone confirmed that the Eiji engine is still the one in the car? Block numbers? If not, The logical explanation is, someone swapped the engines. The reason is obvious.

Exactly. I expected to see something that would indicate the cause. Kind of a long shot but is it possible the pistons were loose in the bore and were rocking? Let the guessing game begin.

After you've heated the stud and nut to smoking hot, Dry or wet ice applied to the end of the stud will chill it rapidly. My theory is the stud will shrink and the nut will stay hot. I've used this method a few time and it does seem to work better than heat alone. Be sure to wire brush any of the exposed stud threads. The nut can break loose and then jam because of the corrosion on the exposed threads.

You should be able to source brass nuts from a local bolt and fastener company. I Googled metric brass nuts. Lots of sources there too. Stainless steel nuts might be an option too.

Were the skirts all broken on the same side? A measurement from the top to the pin center and from the pin center to the bottom of the skirt would be interesting to compare with stock pistons.

Those studs can be the worst part of pulling a trans. The nut splitter is a good idea. Let us know how it works. I broke two studs the first time I pulled a trans. I had to get it back together for the Mon. morning work run so I drilled out the broken studs and through bolted the flanges. Don't forget the Never-Seize thread lube on all the threads.

Not a short, a bad connection. It can be on the supply side, +, usually corroded connectors could also be broken wires or missing or disconnected ground connections. If it was a short circuit to ground, a fuse would have blown. Start looking around the area that you were jiggling. You're close to the problem.

"Good fences make good neighbors" but distance is better than a fence anyday. FBI, living thirty feet away? That's like being tailed by a cop. Even if I'm legal, it makes me nervous.

Just thought of this. Youtube "Datsun 5 speed transmission", lots of teardown videos. Better than pics. Grab a beer and watch others make the mistakes first.

Don't know about the sensors but $700.00 sounds like a lot of money for replacing seals and bearings. Especially when you're handing them the transmission. IMO, pull the outer cases off (quite easy) and take a look at the internals. Look for the bad bearing and then decide how much really needs to be done and if it's worth it have someone else do it. At the least you'll save money by pulling the cases and cleaning them yourself. A used trans is definitely an option but you may end up with a second one that needs to be pulled apart too. Could end up having to decide which of the two 5 speeds to rebuild.

Looks like pieces of a bearing cage. The cage is what keeps the balls from touching each other as they rotate. A ball separator would be a good description. I'm surprised you haven't heard the bearing whining. The trans definitely has to be torn down. It's a big job to do yourself but not impossible if your desire is great enough. The first time I did a Z 4 speed, it was on a 4'x8' sheet of plywood on my shag carpeted apartment bedroom floor. Basic hand tools, not even a press. Replaced synchros and bearings. Turned out great. Except that my bedroom smelled like gear oil for a couple of months. Feb. 10th, Boomguy@ started a thread titled "Any ideas?". The pics of his trans bits and pieces are the same as yours. Undoubtedly there is a lot more info if you search. Note the snap-ring from @#$%. Everyone has problems with that one. The orientation of the parts during disassembly and cleaning is critical and the most difficult, for me, to keep straight. One member suggested wooden dowels to keep the parts in order. Also start soaking all the bolts (especially the exhaust) with good penetrating fluid. 50% acetone, 50% auto trans fluid is excellant. A broken bolt or stud can make a difficult project a lot worse. It's difficult to estimate the time. Too many variables.

Excellent information. I wasn't aware of the internal spring on the later 240s. I did know about the non-adjustable clevis rod. Any idea why they went to the later style? I like the adjustability of the clevis rod and not spinning the T.O. bearing constantly.

About 3 1/2 hours away for me. Mike or Geoff may know someone in Seattle that can take a few pics and help with the inventory.

Pull the return spring from the clutch slave cylinder and push and pull fork fore and aft. There should be a bit of free play between the top of the stroke and in to the point where resistance is felt. That free play is the distance between the throwout bearing and the pressure plate. If you have clearance the throwout bearing isn't turning.

I've had better success using slip-joint (Channel Lock) pliers on rounded, stuck hydraulic line fittings and bleeders than Vice Grips. I resorted to pliers when the Vice Grips just chewed up a bleeder more than it was before. I've found the pliers and a good grip actually do less damage than Vice Grips.

Cap'n Wrongway PPF The pics of the wrong installation are still valuable as long as they are properly identified with Don't Do This.

It might be one of those "metal munching mice" supplied by Gidney and Cloyd. Hop into the "WayBack Machine", you'll remember. Probably spent 20 years stored in Frostbite Falls.

You may find more markings after cleaning the backside. They should look good after cleaning and polishing. I've always like the "look" of slotted wheels.

14". Your assumptions are correct. What brand are they? Ansen Sprints?

The cracked and or broken piston skirts explain how the pieces of the ring got onto the pan. My question is, was did the destruction caused by a bad tune-up (preignition and detonation) or did the replacement head raise the compression to the point of preignition and or detonation?. Low octane gas would have made either scenario worse.

Kira You're not missing anything. That's all there is to the early horn button. The cracked plastic ring is normal. That's why it falls off when you hit a bump or in your case will fall off when you hit a bump. Haven't tried it yet, but the crack(s) could be cleaned, epoxied and squeezed together while curing with a hose clamp. Don't see why it wouldn't work.

Less than 1000 miles, 15 hrs. one way, cheap fuel = cheap engine. I betcha a round trip would be cheaper than shipping it. From the looks of his set-up he can fire it up as is.

Get it running BEFORE the bills start coming in and drive it, You'll have a daily source of joy (healing) around while you're getting thru these tough times and the value for your running Z will keep rising at the same time. WIN, WIN, WIN!