Captain Obvious

Leon, Thanks for the input and I understand about the loss of travel and the increased risk of bottoming-out. I'm running KYB inserts, with stock springs and rubber bushings. In other words, pretty much stock 280Z with KYB's. I've been driving with this setup for a number of years now and I don't believe I have ever bottomed out the stock suspension. Ever. So how close to the limit do you think I am now with the stock set-up? Any guesses? If it weren't for the rubber bellows being in the way, I could put a marker line on the strut shaft and go for a spirited drive and see how much of it was worn off. And Chas, Yes, you're absolutely right. One inch drop on the rears is easy. The idea was just for the front.

Whoa. I got a serious case of diagram envy. That thing is beautiful! I guess now is not the time I should bring up all the mistakes I found recently, huh?

Well I put a whole bunch of my thoughts in your Lily thread: https://www.classiczcars.com/forums/topic/55369-1971-hls30-14938-lily-build/?page=8&tab=comments#comment-550587 Haha! Am I missing the joke here or something?

I'm not a suspension guy, and I got a stupid question... What would happen if I were to remove the lower spring perches from the strut tubes and reattach them an inch lower than they were originally? Make that change and nothing else... Put it back together with everything else the same as when it came apart. No adjustable threaded collars. Stock springs with a lowered bottom perch. The whole sprung weight of the car sits in equilibrium on the springs, so with a lower perch, the same weight should compress the same springs to the same length and that would lower the car by an inch, right? And the only down side would be that I would be at greater risk of bottoming out the strut on compression, right?

Accident on the way to the emergency room. It's like ten thousand spoons when all you need is a knife. So what dimensions are you talking about? Last I saw, you were messing with the calipers I sent and you were still measuring a couple thousandths larger than expected. Did one of us miss a post somewhere?

All that means is that it'll come back again some time in the future.

Well good luck, and I hope I'm wrong. One the good side, however, it's in a pretty easy to work on location, and since the holes go all the way through, it makes it a little simpler as well. If it were me and I found those threads were all ripped out, I would probably just re-tap for a larger size. I didn't verify any of the sizes, but it was mentioned above that the original is M10 x 1.5. I believe M12 x 1.5 is easily available as well, so it would be easy to follow (what is left of) the old threads and create fresh threads of the same pitch on top of the old. But here's to hoping you've still got a couple good threads down in that hole! :) PS - @Mike What happened to the traditional simple smile emoticon? The one you would get with this? >>> :) It's not in the list anymore, and it doesn't seem to show up automatically?

I ditched the inflat-o-matic spare for an always inflated donut spare a while ago. Details are here, but pics are dead because photobucket sucks: https://www.classiczcars.com/forums/topic/55424-always-inflated-mini-donut-spare-for-7778/ The 77 and later cars are tough because of the reduced tire well diameter. The summary is I'm running a T115/70/14 space saver tire on an old 4 inch wide rim from a Datsun Roadster. That's the largest rubber I could get into the spare tire well on the 77. Let me know if you want me to reload the pics and I can do that when I get the chance.

I was going to jump the gun and warn you about that, but I didn't. That was my first thought when everyone was wondering why you had bolts on yours coming through from the inside. I'm assuming a PO stripped out the hole(s) and used the smaller bolt(s) as a workaround. I wouldn't be surprised to hear that the original sized bolt simply will not work anymore, even if it's longer than stock. You might be looking at a heli-coil or retapping to a larger sized bolt.

Wow. That's simply no fun at all! Glad you're OK!

Oh, and forgot... About the bearing seating surfaces. What are the shiny spots at the 10:00 position (and other spots)? Are they dents IN or bumps OUT? I'm assuming they are dents inward, but figured I would check:

Yes, you have to wiggle the calipers around a little and look for the minimum dimension. This is because you are looking for the shortest distance between two points and unless you have the calipers perfectly square to the faces which you are measuring, you will be seeing the hypotenuse of a triangle instead of the shorter side. Problem is, in an application like this, down in a hole trying to register on small surfaces, it's difficult. If you have larger flat surfaces and better access, you could use the wider, flat part of the jaws to make the measurement (like you are doing on the distance piece). But down in that hole on those small surfaces, you are unfortunately limited to using the narrow ground tips portion of the jaws. So you have to "finagle it". And yes, the more pressure you apply, the lower the reading. And that phenomenon becomes more pronounced the longer the piece you are checking because you are actually bending springy things a little and the farther apart the jaws, the easier it is to bend the beam between the two of them. So you have to "just get a feel for it". But on the good side, look at it this way. You have already reduced your hub measurements by at least twelve thousandths. Only a couple more to go! Try doing things like this... First, the bore where the bearing sits does not have a perfectly square corner at the outside. There is a little rounded fillet down there at the bottom of the holes. Make sure you stay away from that as it will increase your measurement. Second, wiggle the caliper around while applying a small amount of pressure until you get the absolute minimum you can find. Let the jaws slip around a little on the hub until you get the smallest distance. That should help position the jaws directly opposite eachother and reduce the hypotenuse effect. Third, move your thumb off the dial, and use the little wheel below the dial to hold the caliper in place, And try to apply the same amount of force every time you take a measurement. See where my thumb is when I'm taking that internal measurement: I'm completely confident in the external measurement you are making on the distance piece. Try to use the "same amount" of force when making the internal measurement on the hub faces? All of this stuff is where "the knack" comes into play. From what I see above, my opinion is that last couple thousandths is "the knack" and you have the correct parts. Zed, Where on the casting is that mark? I've never looked for that mark. Is it in some rusty, crusty spot that is probably undecipherable at this time?

I'm still holding out 95% hope that it was a measurement error. Make sure the bores where the bearings go is clean and there are no burrs kicked up anywhere. I use an eye loupe for magnification of all the surfaces involved.

Oh... Here it is: https://www.classiczcars.com/forums/topic/60007-78-280-re-assembly/ Maybe the "M" spacers are .020 longer than "B"?

Crap... I knew it was just a matter of time before someone asked that question. I don't really have a good answer. I just can't explain how that could possibly be the case, and therefore I don't really have a good solution, other than to make special custom distance pieces to accommodate the situation. Or get "normal" strut bodies that aren't screwy. I haven't looked closely at the sizes involved, but it is also conceivable that one could place appropriately thick hardened washers "in series" with the distance piece to bring it's overall effective length up to what it needs to be to work in a hub that is .020 too wide. McMaster carries some very thin hardened washers. Haha! But I simply refuse to seriously entertain anything like that until someone can prove to me that you have a hub that far out of spec. PS - There was another guy looking for replacement distance pieces because he needed "B" and what he had in his possession was "M". I've never heard of "M" and was curious about what was going on there. I didn't look into it at the time, and now I can't even find the thread... I thought it was on this forum?

Oh, and I forgot... @Patcon The custom hub-fitting caliper is on it's way. You should see it soon. Weds or Thurs.

That's about the only thing I could come up with as well. Since that bronze is softer than the steel, it will ooze out a little if the torque is high enough. Although, I'm not sure the normal expected torque is anywhere near "high enough". Nissan said it was to reduce noise. We talked about it a bunch in this thread: https://www.classiczcars.com/forums/topic/58935-lost-rear-bearing-shim-washers/ They put it in at the beginning of 72 and took it back out the middle of 73: I still think the whole thing was a fire under some engineers butt and that was his knee-jerk bandaid. As long as the marketing guys were convinced, then it was a success.

Looks like it was a great time, and cool that CZCC was well represented. See the way Zup sits there with flat tops at his feet? Like minions.

Nice. Is that the NNJ club? Or the Long Island maybe?

Your memory is fine. It was added to try to quiet something down back there. But the thing is... I don't understand how it could possible do anything like that. The geometry just doesn't make sense. It's like they got a couple complaints back at the factory and they lit a fire under some engineers butt who quickly threw a half-baked poorly thought out fix at it. Then after a couple years, they took that same fix back out. Probably because they realized it cost money and didn't do anything.

That bronze washer has nothing to do with the bearing preload. It's outside the races. You could get the exact same effect by adding metal to the inside face of the yoke and making it that much longer. Doesn't fall into the geometry at all. Doesn't matter. Honestly I'm not even sure what Datsun was trying to do by putting it in there at all. Doesn't make much sense to me. So, here's to hoping it was simply a measurement area. I'll get those calipers out to you tomorrow and you should have them Wednesday or Thurs. I just can't believe your hubs would be out of spec like that.

But before you go applying force to things, I just have to ask... Do you have the room in the upwards direction for that thing to even move off the rack splines? Reason I ask is if that is the only bolt you have removed, it won't come off the rack because it has nowhere to go (up). So... Did you take the bolt out of the upper end to make sure that intermediate shaft COULD move at all? Is the upper end frozen in place?

Sweet. I love it when a plan comes together! Keep your old one in your glove box just in case? I know it doesn't always work right, but it might get you home some night if the new one go wonky in a different direction?

Ooop... I got mail...

I found one round top needle valve. I have no idea if it's factory or aftermarket, but it is the old style with the hardened steel seat and the regulating spring built into it. It measures .079 through hole, so it's at least what the book says is correct. I'm pretty sure I've got a couple others around here somewhere, but I don't know when they will turn up. I will keep an eye open for them though and let you know if something turns up.