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MG MGB Technical - Strange tapped holes in deck by trunk

Hi all,

There are two tapped holes in the deck just above the upper corners of the trunk on my recently acquired 1973 MGB.

These two holes have nuts welded below them, and open directly through to the area above the battery shelf.

They are in the neighborhood of 3/8" to 1/2" thread size, but I haven't precisely sized them yet.

You can see these holes in the 5 photos I have posted at the following link. You should be able to download the photos one at a time.

What is really weird is that both the small and large tonneaus have cutouts in them for these holes....and they look like they were originally made that way. I don't know if the tonneaus are factory original or not....but I suspect it's a stretch to think they are.

The car was originally red and painted white about 10 years ago, so you can't use the paint around the holes as a clue as to their originallity.


http://www.curvedmouldings.com/mgb/

Thanks for taking a look.
BH Davis
BH Davis

Only a guess but maybe the prior owner had fabricated their own windscreen which didn't make it to you when you bought the car.
John

These holes were from where seatbelt anchor on earlier car.
Shawn
Shawn Taylor

BH, Shawn has the correct answer. OE seat belts were mounted in those holes.

Clifton
Clifton Gordon

"Original MGB" shows these on page 57.

Not sure why they were still there on later cars that had retractable seatbelts (my '74 has the holes). I just put some SS "domed" bolts in them.
Simon Austin

hardtop attachment point?
Bruce Cunha

Bruce. Nope. Have a factory hardtop and it attaches to the egg shaped pieces the soft top attaches to at the rear, the brackets the soft top attaches to in front and has two additional brackets which go where the folding top mechanism was attached.

Seat belt anchor points is the correct answer as the others have indicated.

Les
Les Bengtson

Thanks all of you for taking the time to let me know!
BH Davis
BH Davis

I believe the later cars with retractable seatbelts came with a plastic plug in each of the unused seatbelt mounting holes.
Bill Boorse

Detacheable static seat belt mountings to allow the tonneau and hood to be fastened and removed. Left in place after the mounting point moved back to the inner wing, probably because the metal fabricator wanted more money to remove it! Used on MkII North American roadsters, and from 1971 for other markets, until 1977 when all cars got inertia reels.
Paul Hunt 2

I believe Paul has the best answer about why the holes persisted. You will find many "abandoned" cutouts, holes, and welded up nuts on all makes of cars as production procedes because of variances in market requirements, and simply because it is cheaper to keep doing the same thing regardless of need, than to change tooling or incur die alteration expense. Several cars I have worked on over the years simply left the bolt holes in the sheet metal, but saved a penny in materials and process by not having the nuts welded on. These are often the trail of crumbs left by bean counters.
Bob Muenchausen

Thanks everyone for the replys.

Now I'm ready to order up a set of 3-point belts from Moss (Part 222-030) and would like a bit more of guidance on the subject of installation.

The tech fellow at Moss said to use the two floor mounts at either side at the back of the seat for the two lower connections. This is where my current aftermarket lap belts are already connected so this is easy.

He then said to use the trunk deck tapped holes for the shoulder belt installation point. That would mean that the belt would be awfully low coming forward either above the folded up top (top down situation) and below the tonneau, OR, somehow on top of the car body and over the tonneau......which of course means, as Paul pointed out, I'd have to be able to remove the belt connection in order to use the tonneau.

So, what is the best way to attack this attachment issue. Do I use the deck holes (I've already placed a couple easily removed gasketed carriage bolts in them)or is there another attachment point somewhere around the wheel well that I should use? Again, this is a 1973 roadster.....with no roll bar if that's an issue with regard to belt attachment.

I'm going to hold off on the belts purchase until I have a better idea of how they will attach to the car.

Thanks yet again!!!!!!!!!

BH Davis
BH Davis

BH: My car is a 74 and has the re tractor attached to factory installed mounts located just above the wheel arch. I have Securon replacement belts and their instructions for the midget and mgb roadster say "Use bolt and shakeproof washer to fix anchorage point located on side of wheel arch".

I agree the deck mounting isn't a satisfactory position for real type belts. Some people have drilled holes above the wheel arch and backed up the bolts with fender washers. I would want the mounting points welded in. That said, I feel the OE mounting points are too low. The belt is also too long, it's surprising how much a belt will stretch in a collision. There isn't a good alternative choice unless you have a pack away hood, the mount could then be installed at higher position.

If some photos would help email me at flash1929@yahoo.com and I'll send you some digital photos of how the factory installed the mounts for reel type belts on a 74.

Clifton
Clifton Gordon

This thread was discussed between 25/05/2006 and 31/05/2006

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