Front engine access cover

Yes, they can be a PITA.

I don’t think there is much that can be done for the captured nuts. I have switched to longer socket head cap screws, which I find easier to install than using a ratchet and socket with the OEM bolts. Using a screwdriver-style hex driver I find I  can better maneuver/angle/wiggle the bolts while searching for the hole in the nuts.  

make sure to check there is clearance for the longer bolts, and for a little added improvement in installing you could grind the bolt threads down to a point,  which would help make them easier to index with at least a portion of the nut’s hole

I tried using thumb screws, but found the narrow frame of the hatch (so close to the bubble portion) didn’t allow any room to grip them properly.

that’s all I’ve got, but I too am curious if someone has figured out a better approach.

Larry

Put a glob of rubbery silicone adhesive around the square captive nuts when you put them into the metal “capture” pockets.

Then screw the screws in, and allow the RTV to set.

The RTV will let the captive nuts move a slight amount when you are reinstalling the cover in the future, but will hold the nuts in for you.  It’s a great solution.

I use big pan head Phillips screws.  You can use those black “faucet washers” between the screw and the metal cover to cushion things!

Have Fun -

Chuck

The bolt thread on my January 1972 car is M5 – 0.8

10/32 is close but is a bit smaller.

Larry

I use a set screw that is about 3/4" long and red locktite them into the nuts. Let it cure and then insert the bottom of the cover into the slots and work from the bottom up using a screwdriver to lift the screw into the cover hole and attach using flange nuts

To respond to Larry - I replaced the square nuts in the captive housings with a standard US nut/screw combo (10-32?).  You can get square nuts at Ace Hardware…

I also squared up the captive nut holder frames with vice grips & screwdrivers.

Of course, this is easiest when the engine is out…

Forest…. Great idea!

Chuck

Rocky is correct that you can find SAE standard square nuts if you want to start mixing SAE and metric fasteners on your car.

Like many things on our cars, the square nuts appear to be hand-formed by Guido and Luigi. I had a couple on my car that were stripped out, but square metric nuts were nowhere to be found. I looked into buying SAE square nuts and re-tapping them for the M5 bolts, but all of the square nuts I could find were smaller than the OEM nuts.

I wound up making my own from steel stock.

Larry

Lots of ways to (put the engine cover) skin on a Cat!

Great comments.   I had replaced all the square nuts while the motor was out.  Order a set from a vendor and not one fit.  I ground down each to fit the holder.  Worked great with brand new M5 Allen heads for a while.  I'm liking the set screw suggestion from forestg!   I'll be ordering m5 x .8 x 20m and either jam nuts or the flange nuts suggested.   I normally use a washer but maybe with flange nuts it won't be needed.  I'll be chasing all the threads with a thread cleaner (not a tap) and I have one that I may have butchered already. :-/    I think one additional advantage is with studs it'll be easier to manage a gasket.

My enthusiasm for working in 110 degree garage is somewhat limited right now...

...You are 'Right-On'...Flanges don't Require a Washer! But be Advised, any Tiny Part dropped from the Hand, seems to go right down into one of the Holes in the Chassis! I call it 'The Abyss'! And if Stainless, a Long Magnet Wand is Useless! I Tape the Holes up. A Single Allen-Head FLANGED Cap Screw, can be Hung off a 'T' Allen Wrench, easily Guided into the Captured Nuts, and most important, eliminates the tiny Parts.

I feel Your Pain about the Heat in Our Garages. Mine gets to 110F-115F. I cannot be out there Now, we're in a Heat-Wave here in California. Certainly NO AC, as far as the Garage, and Multiple Fans just blow the Hot Air Around.

Good-Luck with Your work

MJ