Taking Apart 240Z Spring Loaded Seat Hinge

[Richie G]

Has anyone taken the seatback hinge apart that has the large high tension spring coiled up?  Safely that is lol?  I'm in the middle of a seat restoration and have the seat type with the full recline.  The side with the lever and gear / spring is pretty easy.  The other side I'm worried its not going to go back correctly or I'm gonna be in for a big surprise after I pull the pin and washer off.  I've done some reading here and saw the same question from about 10 years ago but the replies never seemed to follow through on the answer.  Any help would be appreciated.

Also, I've started the degrease process and was going to paint everything a nice satin black.  There's a ton of gunk on these, especially the mechanism side so it's hard to tell if this is all dirt grime, or some type of lube I need to reapply to the mechanisms.  Thoughts about mechanism assembly after painting?

 

 

[zKars]

Clearly these hinges were never intended to be disassembled, all fittings are permanent rivets and spot welds. 

If I had to disassemble it, I would bolt the seat bottom section to a solid surface (work bench) and bolt a long strong extension to the seat back bracket (like two feet) to give me leverage on that spring when I did grind off the welds or pin heads so I’d have a prayer of holding it back. Then I could hold that long lever and slowly unwind it. Do the reverse to assemble. 

I would also try to convince someone I don’t like to do it for me….

Or just sand blast what is visible and paint it grease it and be happy……

 

[dutchzcarguy]

I'm sure .. i never would take that apart.. sand it a bit and paint it..  look what it looks like after 50 years! It's never gonna brake.. It can work another 50 years this way. (can get dangerous to take springs apart.. i would not risk it.)

[Richie G]

I think you guys may be right.  But I did want to add some pics that i should have added yesterday.  this is a two piece, probably three piece assembly.  Seems there is a wound coil inside the side that has the "well" for it to sit in and then the lever side has that welded pin you see in a slot probably applying tension against the coil.  They certainly don't need any repair, the tension is extreme so thats why i was so worried.  I've heard others complain about the console side of the seat swaying back and forth, must be from a broken one of these.

This was that other thread I was referring to, curious if anyone back then is still around for definitive answer?

cafebaltimore seemed to have done it but doesn't explain how?  unfortunately he's not been here since 2017 to ask.

 

[zKars]

Right! The cotter pin! 

With that it will be easy. Bolt it to the bench, put an extension on the arm of some kind, pull the cotter and pin, and un-wind it. Easy peasy. 

Make sure your life insurance in paid up first…..

[Richie G]

  Paid up, but not sure I'm ready to cash that in yet.  I like the idea of extending the arm to increase leverage, its a son of a gun to try and pull back just in hand.  I've got tons of other stuff to get to, might leave these for a bit until I'm up to the challenge.  I don't really have a good working bench at the moment so bolting them to something with enough of a sturdy platform is something I'll have to work out.

[Richie G]

OK so i took a chance since cafebaltimore seemed to have no issues.  Well, he was right.  No danger nothing to worry about.  Since i had no bench i went and made a makeshift set of blocks and just put it between there thinking the worst that could happen was the spring would unwind violently sending the base spiraling out of control.  Set it up as shown to have some control over the base, pulled the cotter and washer and just a slight tap with a hammer dropped the pin out and nothing happened.  the tension coil isn't under tension until you assemble it.  second picture is all the components.  piece of cake.  Now i can clean and repaint as needed.

[zKars]

Well I’ll be horn swaggled….. All the invented drama for nothin’ Been watching too much reality TV apparently. 

When seat back is all the way forward, no tension. Nothing happens until you start pushing it backward. Duh…. 

I’m going to go take some apart just to laugh at them….  

 

[Richie G]

Lol well to be totally fair there's a little bit of tension when I put the spring back in the well and then take the lever side and line it up with the pin you do have to give it a little bit of a pull in order to move the pin that's welded onto the lever into its slot about a quarter inch so nothing to really write home about but just to be fair little bit of a pull is necessary to put it back together

[Richie G]

Just wanted to post some after pics of what've Ive done.  Heres some before / after comparing a pair of the seat hinges I've finished vs what i took off the car.  They aint perfect, but they are 100% better than what they were.  The pics don't do justice to how badly pitted and so grease / dirt bound the mechanisms and steel were.  Not bad for a 1st time DIY'r like me.  Feeling good about the rest of the work I have planned.  Also picked up a pair of the re-pop mechanism covers that were missing from both sides which I'll add back to the car when i finish the seats fully.