Rear floor given way drivers side

[nickh7]

Big Bang out today thought it was a rock hitting the floor turns out the floor has come away from the chassis rail.  Was going to get it up in the axle stands tomorrow and take a look. 

Are these different pop rivets at the on the floor? Or am ok to use standard rivets all be it slightly bigger ? 

 

Thanks

[7 wonders of the world]

These should be steel rivets as the ally ones suffer metal fatigue and fracture

[nickh7]

Thanks ,  ive got some of those 

[Golf Juliet Tango]

I have come close to this with floors descending.

[Drumster]

From my experience it's not the rivets that's the problem but the fact that the rivet holes in the aluminium floor panel have stretched causing the floor to 'slip' over the rivet heads.

Very early 7s had seat supports that ran along the floor to take the weight of the seat and it's occupant. These were attached to the front cross member and the lugs on the rear bulkhead.

I had some made up (yes, i know it adds weight  ) but I've not experienced any problems in the last 10+ years.

I don't use seat runners so both seats are still bolted through the floor panel and the above supports are sandwiched between seat and floor, but the weight of the seat is taken by these struts.

[Molecular--Bob]

Hi Nick

How many rivets do you need to do? I have an air riveter you are welcome to borrow if it will make your life easier. Popping a lot of steel rivets by hand will give you forearms like Popeye.

Ian B

[SLR No.77]

Just get some steel rivets and fit them with a hand riveter, there’s not so many to do that it’s worth taking time setting up with an air riveter.

Stu.

[Roadsport06]

I had this years ago on the passenger side. Steel rivets and it has been fine since. Hand riveter will be fine, you'll feel the steel rivets needing more work to install though.

[The_ASH]

I’m surprised this doesn’t come up more often, the removal of the steel seat supports mentioned above means the floor and riveting takes it all. If the seat is forward and away from the rear bulkhead there is leverage backwards and downward which plays on the floor, if the seat back is against the bulkhead then most of the resultant flexing force is up/down, both will lead to failure eventually.

There have been previous posts where lowered floors have stress cracked in a similar place along at the inside rear, I also remember seeing cars with standard floors where a crack leading off inwards towards the rear edge of the floor. I even remember seeing cars with the seat supports with cracked floors at the rear inner mount.

If found at MOT depending on the tester it could be a ‘fail’ item, certainly worth checking for especially on the unsupported and lowered versions as any flexing of aluminium will eventually lead to failure and is something to think about next time you drop into the seat with a big thump... where did all that force go?

I’ve always believed that Caterham’s deletion of the floor reinforcement bars was a mistake as it just means the inevitable will happen sooner. Equally I can see why they were deleted they were blooming heavy, question is which would you rather have heavy brackets or a 10/20 year floor replacement and the possibility of the rivets pulling out (and the potential for an embarrassing Fred Flintstone moment) as has been witnessed?

[nickh7]

Done, 26 rivets replaced with heavy duty steel version, old pop rivet gun died half way through so rushed down to Halfords for replacement. Hands and arms killing now . 

[The_ASH]

It’s a real snap/bang/elbows thing when the rivet finally lets go isn’t it!... I still feel/remember it 15 years later, much more than an ally one and I don’t think I had to do as many as you.

[elie boone]

For a healthy bloke that had it twice i just replaced the rivets with M4 bolts. Better get a Live axle chassis they always have the metal supports.

[SLR No.77]

I did both lowered floors, tunnel panels, "outer-inner" panels, front and rear bulkheads and passenger pedal box with a hand riveter ... about 700 rivets. I needed a new riveter when I'd finished but no great issue doing it by hand. We're reasonably tough up North!

Stu.

[The_ASH]

Or as far as I can remember any pre-central handbrake chassis 93-94ish.

[The_ASH]

Was in or just post en-gin-earring at the time, used to stuff that was screwed, bolted together, rivets always felt like a bodge as a/c ductwork contractors used them/the crappier manufacturers used them to mount stuff like condenser fans making my life hard when they failed (on the upside previous successful projects like the Spitfire, Lancaster & Queen Mary used them to good effect), didn’t possess a riveter before owning a Seven, so I had to buy a hand rivet gun (Draper I believe) to complete the task with the car sat on the jack at the front. Later I learned there are short and long handled riveters for different types sizes, compositions and applications.