How to fix top rails to the bottoms of 1968 sport seats (?)

[M491]

Hi all. Well, I finally have everything I need to get my 1968 factory sport seats into my 1972 911 coupe, including the original tilting seat bases and height adjustable sliders. Now comes the next step. The seats had no top rails installed on the bottoms of the seats. I have the rails, but am wondering what hardware to use to attach them to the seat. Were they some kind of rivets, sheet metal or machine screws? If they were rivets, clearly they would not have been aluminum rivets because thay don't seem like they would be strong enough. What's the best source for the proper hardware? I'd hate to have the seats attached incorrectly, which could end up being dangerous in case of a accident. Does anyone know? Thanks for the information.

[72tii]

On my '68 sport seat the top rails are attached with machined cap screws. I'm not sure of the size, but I think they are 4mm or 5mm.

[Allen Henderson]

M,

The early 67/68 seat rails were attached to the seats with sheet metal screws! This truly was and is dangerous..still I will admit that is the way mine will be done. You can have captured nuts installed in your seat bottoms (think this is best done if you are having your upholstery redone--note sure btw this is why mine isn't changing) but might be put in without doing that. Then you would use machine bolts, much better.
When I took out my original screws from rails to have my rails replated, on of the screws was alreayd striped from the sheat metal and I'm pretty sure they had never been off before. Not good design really.

-Allen-

[M491]

Wow,

Well, sheet metal screws won't do for me... I wouldn't want to become a projectile. I guess I'm going to have to figure out a way to use hardened machine bolts. It's probably going to involve releasing some of the upholstery loops to get into the seat frame. I won't be welding the nuts in, but I will have to use nuts and washers on the inside. If anyone has any ideas or has already done this, I'd appreciate hearing from you. Thanks.

[ttweed]

Mauro-

You might consider using a Rivnut fastener. They are a blind, threaded insert that will accept a machine screw after installation with a special tool. I usually just borrow the tool from my mechanic to keep the cost down, as I haven't used them often. Here's an example. I would use four 6mm allen head socket screws per rail, preferably grade 12.9 steel.

HTH,
TT

[Allen Henderson]

Mauro-

You might consider using a Rivnut fastener. They are a blind, threaded insert that will accept a machine screw after installation with a special tool. I usually just borrow the tool from my mechanic to keep the cost down, as I haven't used them often. Here's an example. I would use four 6mm allen head socket screws per rail, preferably grade 12.9 steel.

HTH,
TT

Excellent idea Tom! I think I'll look into that. Thanks.

-Allen-

[M491]

Thanks Tom. That sounds like the right idea.