Seat rail difference?

[RS02]

I was tearing into my old seats to take the rails out and fit them to my bucket seat. But then I noticed that the passenger seat rail doesn't slide back all the way. With the car being 50 years old I thought they must have just jammed. But after I lubed them up and slid them back and forth a bit they still refuse to go back to the rearmost notch. At this point I started taking them off the seat and was going to take them apart and figure out what is going on. 

However, after I spent 20 minutes looking at them I realized that one of the rails may not be intended to slide back all the way! I then searched around the internet for similar informations but didn't see any. So I decided to put it here and see what you guys think.

Here's the rails in question.

They are stamped LH80 and RH20. I presume they are LEFT HAND and RIGHT HAND. what the number is for I have no idea. The LH has the handle coming out to the left and I think should be on the Left hand seat. LH can go back all the way taking the rearmost notch while RH can only go till there's 3 notch still left and gets stopped. 

The reason that I believe they are intended to move back different amounts is that the little indentations are different on them. These sliders work by having two slider carriges in them. They appear to hold one cylindrical roller in the center and some balls on the outside of the rails. They get stopped by the indentations pressed into the rails. This is where the location of the indentations come in.

Here's the rails side by side for comparasion. they are clearly pressed in different locations.

What's more, The RH one has an extra one visible on the seat side of the sliders. These appear to trap the roller in between the rails and prevent them from sliding back further. 

So, can any of you helpful guys confirm this by going out and sliding your seats all the way back and comparing them? Does this still apply to RHD cars? What is the reason for limiting the travel on the RH seat? (My theory is that nissan was worried that if you slide it all the way back you may not be able to reach the throttle on a RHD car, maybe they think the western market are taller and this was not a concern?)

Sorry for the dodgy pictures and the dodgy english. I'm lucky my profession is mechanics and not journalism. lol.

[Patcon]

Were these two rails on different seats or the same seat?

[RS02]

12 minutes ago, Patcon said:

Were these two rails on different seats or the same seat?

Different seats. They are both the locking side (one with the handle). The other rail is just a slide with no locks no stops.

[HS30-H]

5 hours ago, RS02 said:

So, can any of you helpful guys confirm this by going out and sliding your seats all the way back and comparing them? Does this still apply to RHD cars?

This is a 'known' known. Same is true on RHD cars in my experience (both UK and Japanese market variants at least) and is a mirror image of the LHD layout. The passenger seat rails do not allow the same amount of rearward positioning as those on the driver's side.

I've read the reason for the difference somewhere in the past, but now can't remember where, or what the reason was...!

[zKars]

Yup, it's real. Drive me nuts trying to figure it out. And its not something you can change, the dang stops are inside the rails and built right in. There is a domes punch area (or two) right through the body the forms the stop. Tried to drill one out, discovered there were two, metal shavings were getting everywhere, like inside the rail in the grease, gave that up real quick.

Played with enough of these to think it only applies to the early non-flip forward seats. Never encountered it in 72-3 and later seats. 

It's either to prevent the passenger seat from going back too far to interfere with what's behind, aka the tool bins, or has something to do with limiting leg room so the passenger will have his/her feet on the floor boards or access to the glove box, what with those lovely fixed belts..... Is the foot rest option thing involved in that? Talk about a WAG......

[RS02]

44 minutes ago, HS30-H said:

This is a 'known' known. Same is true on RHD cars in my experience (both UK and Japanese market variants at least) and is a mirror image of the LHD layout. The passenger seat rails do not allow the same amount of rearward positioning as those on the driver's side.

I've read the reason for the difference somewhere in the past, but now can't remember where, or what the reason was...!

That's interesting. I would've thought the RHD cars would just allow the passenger to go back further and keep the driver in place. Turns out all of them allows the driver to go back all the way but not the passenger.

[RS02]

Well I welded in my passenger seat mount tubes using the driver seat as a template because of the rollbar tube behind the seat... Guess I'll have to modify them again to put the passenger seat in or live with a slightly forward seat position on the passenger side...

[HS30-H]

2 hours ago, RS02 said:

That's interesting. I would've thought the RHD cars would just allow the passenger to go back further and keep the driver in place.

I don't know why you'd think that?

This appears to be a deliberate decision to limit rearward slide for passenger seats in both LHD and RHD configurations. In both configurations the driver's seats have full travel available on the rails. I vaguely remember the reason being very simple, and I'm racking my brain trying to remember what it was!

[RS02]

2 hours ago, HS30-H said:

I don't know why you'd think that?

This appears to be a deliberate decision to limit rearward slide for passenger seats in both LHD and RHD configurations. In both configurations the driver's seats have full travel available on the rails. I vaguely remember the reason being very simple, and I'm racking my brain trying to remember what it was!

Well it's just my simple brain trying to put a reason to this madness lol! I thought that since they didn't change the hand brake position maybe they just didn't think about the rails when setting them up. Now that you've cleared this up looks like there's 4 different part numbers for the locking side rails. Take it easy on remembering things, Last time I tried to think BAD things happend!😁

[HS30-H]

7 hours ago, RS02 said:

Well it's just my simple brain trying to put a reason to this madness lol! I thought that since they didn't change the hand brake position maybe they just didn't think about the rails when setting them up.

Handbrake/E-brake positioning on the S30-series Z is defaulted to RHD configuration. Making both RHD and (re-sited) LHD configurations was deemed too expensive, so they went with the ideal RHD positioning for both. The only S30-series Zs to get a re-sited handbrake lever were the LHD Nissan Works rally cars.

I think they certainly *did* think about the seat runners/rails, and that's evident in their handing and part identification. Another example of attention to detail that runs deeper than we might often give credit for. Perhaps a good example of that generation of Japanese engineers, who took pride in even the most humble componentry. 

[Carl Beck]

On 7/1/2021 at 4:54 PM, RS02 said:

Well I welded in my passenger seat mount tubes using the driver seat as a template because of the rollbar tube behind the seat... Guess I'll have to modify them again to put the passenger seat in or live with a slightly forward seat position on the passenger side...

Just get another set of rails for/from a driver side seat - and put them on the passenger seat. Yes the adjustment lever will be in the "wrong" place, but then who cares - your are not building a stock set up anyway.  I changed my passenger seat slides, to driver slides for two reasons. My son is 6'3 and I needed to get him farther back so he wasn't blocking my view out the right side window, in addition to giving him more leg room.  The right side slides were never a problem with the wife, daughter or girlfriends as passengers, nor when the boys were younger smaller. So I think for most people the difference wasn't usually noticed. 

I do however appreciate your effort to figure out and document how the rearward travel of the passenger seat was mechanically limited.

FWIW

Carl B.