Captain Obvious

Nice work so far. Taking the bull by the horns and not wanting to be simply referred back to the FSM. Here's a chart I whipped up a while back to evaluate the resistance measurements from the air and water temp sensors: *This chart was created using the Stienhart-Hart Equation with coefficients derived from data points in the manual.

Nice plating! You're clearly getting better results. And I like the way you pulled the plunger apart. I wasn't sure how much force it was going to take and I didn't want to use the threads to jack the assy apart. But now that we have seen that it's not a huge amount of force, your fixture is clearly capable and is a lot less wobbly than what I did. I'll do that next time (if there is a next time). If you use one of your anvils to support the bottom 180 degrees (and spread the load), you should be able to re-peen the other side. Mine had three punch marks 120 degrees apart. How about yours? The same?

As mentioned already, if you have the correct bushings, they are supposed to be tight. I found that the brand I had didn't even fit right when new. No guarantee that all brands are the same, but here's my experiences with the poly rack bushings. Long thread, but my pics have been reloaded on page four: https://www.classiczcars.com/forums/topic/48621-steering-rack-disassembly-and-refurb/?do=findComment&comment=531913

As soon as I'm done with it? Haha! Let me see what I can come up with. You can see a whole complete poppet valve plunger in the bag in pic that Kats posted. Complete with seal already on the assembly and crimped together. So it's clear, not surprisingly, that Nissan was never expecting that plunger to be disassembled: I had mentioned it before, but the only reason I even ever started messing with taking it apart was the one that came in my rebuilt booster had been disassembled and had a new seal installed by the rebuilder company. So I knew it was at least "possible". Here's a question for ya.... What is the recommended replacement procedure for that poppet valve seal on the Mustang booster? It's included in the kit, so clearly they are expecting you to use it. Did you find any pics or instructions for the expected use of that rebuild kit from Harmon? In other words... Does the Mustang poppet valve assy come apart and go back together easier than the one from Hitachi? Is the Bendix version easily repairable or is it crimped together like the Hitachi version?

Haha! I figured when you were thinking of taking that poppet valve apart, you would need that seal. I believe replacement does require disassembly. I don't think there's any way that seal will stretch over the end for replacement without tearing it. It's just too large of a change. And the rebuilt valve I have was clearly reassembled by Cardone. I don't think it would be too difficult to build a little fixture to re-peen the end. I was picturing a half round support for underneath made out of quarter inch thick plate and then a small punch on top to press the dent in. Do it on the hydraulic press.

Bummer about cracking the bakelite disk. I would have been with you on using JBweld to seal up the small holes, but I'm not sure I would try to repair the rest of that damage. I'm thinking a replacement would be prudent. And I'm sorry that it's too late, but here's how I got my stuck retainer clip out. Couple small rare earth magnets. Very strong for their size: And this is what my poppet valve plunger looked like when it first came out. Looks just like yours: As for disassembly of the poppet valve assy... The end piece is crimped into place and is not meant to be disassembled. You can see the dents of deformed material that hold the end on. The only reason I even knew it was possible to take it apart was that I had bought a rebuilt booster and it was clear by the marks on the valve that it had been disassembled and subsequently reassembled. I don't have any pics of the "rebuilt" one, but you could see that they had "repeened" the dents that held it together. Of course, the workmanship there was suspect... It looked like they whacked it with a center punch a couple times around the circle. But the point is... They were doing it, and I figured I might try it on my spare valve. Had nothing to lose. So I cobbled together a "fixture" from cut-offs and shorts and whatever chunks of metal I had laying around: And put it on the hydraulic press to push the end off the valve shaft: Here's what it looks like when it comes apart: If I was going to be doing more of these, I'd build a better fixture for taking them apart, but since I wasn't even sure it would work, I spent very little time on it. It came apart easier than expected. Might even be a small enough force that you could cobble up a "puller" using a large C-clamp instead of using the hydraulic press. And for the reassembly, I would try to recreate the original dimples, but I won't move to that part until I get the seal from you.

Like so many other topics, seemingly simple things like that groove in the bearing can actually be quite complicated. Apparently the groove design is dependent on the application. Here's some interesting info on such things: http://www.nationalbronze.com/News/410/ Now in the application of the steering rack where the lubrication is never replenished from a pressurized source, I'm not sure how important it is at all. I'm no bearing expert, but I'm not sure the exact shape of the groove would matter much in that application.

I haven't done a coil over project, but I thought they used a slip over collar and did a lap joint. I think that would be better. Can you slip a collar over the slits after you weld them up and then weld the collar in place? I think that could buy you some time while you looked for a replacement. Another hurdle / test will be when it hits the alignment rack.

LOL. Yeah, I know. Far be it for me to suggest that someone else is doing something like that. In my defense, however... My understanding is that everyone seems to be in agreement that it's bent. I thought the "understanding" part of the problem was already over and we had moved to the "what to do about it?" part. If that's not the case, and a definitive cause for the lack of clearance to the tire has not yet figured out yet, then carry on! However, if that strut tube has been bent, then my humble opinion is that I think replacing instead of trying to bend back is the proper course of action.

Buy... Another... Strut... Housing!!!! C'mon man!!! And I thought I spent a ridiculous amount of time on things that I never should have done in the first place. It was tweaked. Enough to exceed the plastic deformation rating of the material. It'll never be the same again. Buy another strut housing!!!

Oh, and BTW... It's not just you. On my first booster disassembly, it took me an hour to figure out how to get that clip out. Mine was a little gummy and a little rusty and if not for that, it probably would have fallen out by accident. But between the rust slurry making a little sticky and the not knowing what I was doing, I spent at least an hour on it. If it's clean, put it on the bottom side, press the plunger slowly, and it will fall out simply from gravity.

Yes, there is a little U shaped retainer at the bottom of the plunger that holds it in. But the only thing that holds it in is friction from the plunger spring. If you push the plunger in a little, it will unload that pressure and that clip will most likely fall out unless it is a little rusty and stuck. If that's the case, a small magnet can help pull it out. But to answer your question... Yes, you have to take the pressure off. And that is done simply by pushing the plunger in a little bit. If you push it in a lot, it will spring load in the other direction... There's a small "sweet spot" in the middle where that clip isn't under any load. In fact, the only thing that holds that clip in when you pass through the sweet spot is the rubber diaphragm sitting in the groove. I've got some pics that would help describe, but my picture hosting server is not cooperating today.

Oh, and your clamshell tool looks just like mine! I screwed some two inch long 2x4 cutoff stubs to the edge so I can use my big bench vice to turn the planks. I thought I had taken some pics of that procedure, but I can't find them. Probably misfiled...

The part at 7:00 to the port is the poppet valve seal. That's the part I want. In fact, in preparation for you to send it to me, my spare poppet valve fell apart earlier today:

Here's the comparison pic between 240 and 260 from that other thread: I'm wondering if anyone has done a similar comparison for the 280's.

Leon, Other recent suspension discussions reminded me of this thread and I wanted to circle back around a little. First, I took a look at putting a zip tie on the strut shaft, and with the bellows in the way I don't think it's possible. Just not enough room in there to lift the bellows out of the way. You might be able to get in there and do that if the bellows were not installed, but with the bellows (stock style with the bottom retainer clip) installed, I don't think it's possible. In another thread, there was discussion that they changed the spring perch location between the 240 and the 260. Lowered it about an inch for the 260: https://www.classiczcars.com/forums/topic/38373-240z-eibach-springs-in-260z/ Have you ever seen a similar comparison between the 260 and the 280? In other words, do you (or anyone else) know if the front perch location is the same from that point on to the end of the 280 run, or did they move it around again for one of the years?

Cool! I did a bunch of digging around on the website for the guy you got that kit from, and I noticed that he was using the same pictures for several of the kits. "Stock photo" and not necessarily accurately representative of what they parts really looked like. I was worried that what you saw might not be what you got. Can you take a pic of the other parts besides the diaphragm? I'd be interested in taking the poppet valve seal off your hands and seeing if I can get that onto my old booster plunger. Also, are there any numbers cast into the new diaphragm? When I had my rebuilt booster apart, there were numbers on the diaphragm inside that I wrote down somewhere. I'm wondering if they got their diaphragm from the same source. I wonder how many people in the world are casting that part.... In other words, I'm wondering do all the rebuilder companies get their stuff from the same source, or do they all make their own?

A build date of 8/74 seems pretty late to me. I don't know when they started with the 75 280's, but I wouldn't be surprised if yours was near the end of the run. So based on that, I would guess your 260 is a late version... Big bumpers like the 75-76 280's? Turn signals up in the grill instead of below the bumpers? And to the topic at hand... Wide groove on the steering rack requiring the wide version of the rack bushings.

Yeah, those bushings are too sloppy. That'll be the first biggest contributor to slop in the steering if the whole rack can wobble around in there and even slip side-to-side. I haven't looked into it in depth, but my assumption would be they changed the rack at the same time as a bunch of other 260 stuff like going to the bigger bumpers. Part of what they call "early" or "late" 260. Is yours an early or late 260?

Except for the fact that really wide tires on the back looks really really cool. OK. I'll stop now.

The reason they need a spherical bearing there is because the engine can move in any unpredictable manner, up / down / left / right. They account for all of that with the spherical bearing. Then they account for fore and aft with the shepherds hook which can extend and compress. Between the spherical bearing in that piece of the linkage and the shepherds hook, they account for every direction of engine movement. My description of taking that part apart? There is no nut on the back side, but there is a swaged (think rivet) joint holding the assy together. I cut off the flared section on the lathe and pulled the retaining ring off the back. The part I don't remember is exactly how I held it back together again once I was done. It's back together, but I don't remember what I did there. I remember threading something.... I wonder if I have any pics of that process. I'll check when I get a chance.

Other than it looks really really cool. I've been considering doing something like this, and it ain't for performance.

Kinda hard to tell from the pics, but it looks like your driver's side rack bushing may not be the correct version. They made narrow (older) and wide (newer), and they change sometime in 74 with the 260Z. Does that driver's side bushing fit tightly into the groove on the rack, or is there a gap on the side(s)?

Woof. No fun at all. Here's hoping for a speedy recovery! Have they got PT in your future?

To each his own then. Haha! My fuel pump and AFM are working great. You're the one that that refreshed this antique post about a sticky throttle body. My throttle body was only sticky when the engine was warm and only when it was running. So needless to say that mine unfortunately mine wasn't as simple as the carpet being bunched up. I also disassembled this part and made a new spherical bearing for inside. That took a lot the slop out of the linkage, but it didn't do anything to fix the sticky idle. Problem was in the throttle body itself.