Removing lap straps......and then I make a worrying discovery!

[twincamtim]

I am in the process of swapping out my tired old leather seat for a tillet and have just started the process, but have hit a couple of problems.

I got the old seat and runners out without a problem and then set about the lap strap mounting bolts. The tunnel side came out (too!) easily but the outside one doesn't want to budge, even though it has had a good soaking with penetrating stuff. Before I start using serious power (spinach ) I wanted to check I am not missing something - it isn't an opposite thread or something is it?

Oh, and when the seat came out I discovered the floor has parted company with the chassis on 2 sides - the rear and the tunnel side . The rivets have all stripped out. It appears the strengthening support channel nearest the tunnel has split about 3/4 of the way down and this might have precipitated the floor failure. Is this a part I can readily replace? I presume all I need to do is re-rivet the floor once the support is replaced/repaired?

I have no idea when this failure occurred but it was due for an MOT in June, now December, so it might have gone unnoticed if I wasn't working on it - another plus for upgrading? I wonder what would have happened if I hadn't discovered it - gravel rash on my backside?  

[1999 1.6 Supersport]

[Roadsport06]

I replaced the ones that had popped with stainless steel ones. You certainly get a work out with those ones.

[nickh7]

I replaced the floor rivets with steel ones but you'll need a electric or air riveting gun to save your arm.

 

Chris Mintoft at Redline is your best bet for the u channel.

 

As for the bolt how long have you left the penetrating oil to work ? Over night night might be required. Then try tightening a tad first.

[Blue C7]

Also use a punch and hammer in the centre of the bolt head to shock the thread often works for me

[Molecular--Bob]

You can snap the heads off the lap belt bolts, and then you are in a world of pain drilling it out ( I have that badge), so be patient and let the Plusgas do its work. I used a gas mini torch on the bolt to heat the bolt head and break the rust, then plus gassed. I cut a hole in a plumbing heat mat for the bolt head to poke through to try and protect the panels.

[Wrightpayne]

Unless you fit tyres for a living I'd borrow an air riveter. The lazy riveters are OK if its on a two post lift with more than 12" ground clearance! 

The pneumatic ones have a satisfying clunk when you pull the trigger!

[7 wonders of the world]

20 mins spent tapping the bolt with a toffee hammer will yield good results along with a good dose of Plusgas - which is better than normal penetrant.

Then tighten the bolt a nats bollock before undoing it, work back and forth with aditional plusgas.

When we are free of lockdown see if you can borrow an air riviter I replace 6 steel rivets by hand and its not a pleasant job, 

[Mark w]

I replaced some of my floor rivets with steel ones after the originals failed. The hand tool was fine , just added a length of steel conduit on the handles to give a bit more leverage .

[Obodiah]

I've just replaced all the interior panels with carbon ones and can confirm that Caterham definitely uses stainless rivets to fasten the lowered floors to the chassis - much more difficult to remove.  I replaced them with stainless sourced from Accu.co.uk who also do them with a black finish.  Air riveter is the only tool for this job IMHO, especially the rivets in the footwell.  Good luck with the repairs, looks like you got to it in time !