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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - D Nuts on TD Toeboard

The toeboard (that piece of sheet metal between the bulkhead and the floor part of which can be seen in the pic below) has four D nuts at the bottom, two on either side, to secure the front of the timber floor. I have posted a pic provided by Matthew M some time ago showing one of the the nuts in situ. FTFU has two sizes of D nut 1/4" and 5/16". As the rest of the floor is secured with 1/4" BSF fixings I'm guessing they are also 1/4" BSF. Can anyone confirm the correct size of these D nuts for the TD? Cheers
Peter TD 5801



P Hehir

Yes 1/4 BSF on all floor board fixings and trans tunnel to toe board

Also sending you an email.

Bill Chasser
TD-4834

W A Chasser

Bill does this include the four D nuts? I know about the others. Sent you a reply about the glove box flocking. Cheers
Peter TD 5801
P Hehir

Peter - If my memory serves me correctly, those 'D' nuts have a grove around side. The grove is supposed to be set in one side of sheet metal and bolts hold the two pieces of the floorboard together. Cheers - Dave
DW DuBois

Dave that sounds right. They should push in from above (I'm guessing a nice press fit) and then the lip or groove prevents them from dropping down all the way. The lip gets sandwiched between the timber floor and the toeboard with the bulk of the nut below the sheet metal as shown in Matthew's pic. If I have to I'll use the MIG to secure them. My toeboard is not original as it looked like Swiss cheese when I bought the car in 1969 and so I had a new one knocked up with just the essential penetrations. Cheers
Peter TD 5801
P Hehir

Peter. Again yes. All the D Nuts will be 1/4 BSF. This includes those for the trans tunnel to toe board and the floor board to toe board. Sorry if my response wasn’t clear. The curved portion of the D nut groove is placed into the the pinched hole in the toe board and the flat side of the hole is then deflected a bit to retain the flat side.

Thank you for the email. Will respond offline

Bill Chasser
TD-4834
W A Chasser

Peter: Now I want you to figure out which places should get the machine screws with flat bottoms and which places should get the machine screws with the cone bottoms. :-)

I think I know the answer but not 100% certain.
Christopher Couper

Peter, the original D nuts are hammered on the inside to fit, no welding etc.

There is a small recess in the panel to equal the hammered part to sit flush with the rest of the panel.
Rod Brayshaw

Thanks Bill and Rod. As stated my toe board isn't original so I'll probably have to weld them into position. I have some original 'D' nuts somewhere and when I find them I'll take a few pics and post them here.

Chris, Matthew's pic in my first post above suggests that the cone bottoms are fitted to the 'D' nuts. Apart from that I'd be guessing.

What I'm uncertain about however is the other fixing shown in his pic. This doesn't appear to be either a 'T' nut or captive nut and it isn't a 'D' nut. It looks like a 'T' nut with flat sides. The other unrelated comment is that the floorboards don't appear to have the 60 degree beveled leading edge as described in Roy Chalberg's drawing of TD floorboards. This is odd as I understand Matthew's floor is original. Chris or Rod maybe you can tell me how many 1/4" BSF 'D' nuts were fitted to the floor originally? I thought there were only four. Cheers
Peter TD 5801
P Hehir

Peter. I was prepared to say 4 D nuts on the toe board floor. But then I went out and looked at the toeboard on dad’s car which is setting loose. It has two on the curb side and one outboard on the drivers side (LHD). But it also has a piece cut out of the inboard side where I thought a nut would have been. I can’t access any more of my toeboards to see if this is correct or if it had been modified. I’ll have to feel around under TD-4834 to be certain but that won’t be until tomorrow at the earliest. Hopefully someone else will chime in. My two sets of lloosr replacement floor boards are of no help as neither set were predrilled. Sorry I can’t be more help at the moment

Bill Chasser
TD-4834
W A Chasser

I think my Toe Board was in worse condition than Peters.
I wanted to use it for two reasons.
First it was original.
Second I already had it powder coated.
Top left frame shows it as I started. Several D-Nuts were missing.
I made my own. I made several mistakes.
1) The step between the swage and the body needs a radius. I should not be sharp.
2) the step should be much shorter. The thickness of the Toe Board + 1/16.
The step should be annealed before swaging.
Top Right shows the flat going on the D-Nut.
Middle frame shows the D-Nut swaged in place.
Bottom shows the fracture Lip, resulting from the three mistakes I noted.

Jim B.



JA Benjamin

"What I'm uncertain about however is the other fixing shown in his pic. This doesn't appear to be either a 'T' nut or captive nut and it isn't a 'D' nut. It looks like a 'T' nut with flat sides."

Essentially correct. These are like T-Nuts (captive). Perhaps they were used in places where expected torque would be higher, and/or there was less space on the side than a wider round T-nut would require.

"Chris, Matthew's pic in my first post above suggests that the cone bottoms are fitted to the 'D' nuts. Apart from that I'd be guessing."

I am not certain and at this point it would be hard to tell unless we could find a car that never had it's floor boards out.

I think it has to do with the number of objects that are sandwiched together through the bolt. ie in places were they had alignment issues they used these bullet machine screws to get the bolt in in less time and with less likelihood of stripping out the captive nut.
Christopher Couper


I Believe:

The reason for the flat, or
"D" on the captive nut is the shoulder on the round opening.
The nuts are captive and swaged.
If you tried to uses a full round nut it would need to be moved further back from the edge, leading to a larger flange on the cover over the transmission.
So a flat was added.
There are two nuts that did not need the flat.
But rather than have a special par, SB used the flatted ones, just to keep parts inventory simpler.

Just my feeling.

Jim B.
JA Benjamin

Jim: Sounds reasonable to me. :-)
Christopher Couper

Still gathering info on the 'D' nuts and the other fixings on the toe board. Both temperature and humidity make tub painting impossible now until about October at the earliest so looking to sort out the toe board. Rod advises that the 'D' nut is hammered into the recess on the bottom of the toe board, but isn't welded into position. Jim's have been swaged. I'd love to see a close up of an original 'D' nut that hasn't been fitted, as I plan to make mine from steel plate with a welded on washer, as I don't have a lathe. I have pics of installed items from Bill, Matthew and Jim's bespoke jobs but none of the 'D' nut itself. Cheers
Peter TD 5801
P Hehir

Since we are in the general area....I'm wondering when the fixing nuts on the bulkhead were changed. This image from my 52


L E D LaVerne

And these from the early 50


L E D LaVerne

TD 4618 has them like your 1950 picture (see picture) but TD 11272 has them like the 1952 picture. So we will have to see who else can bracket this.

Good catch.


Christopher Couper

My Feb 1951 has the bulkhead captive nuts like those in Laverne's 1st pic. I had to replace a couple. Not that hard to make using an ant cap for the sheet metal and some flat bar to make the 5/16" BSF nut. There's also the strange fixing shown in Matthew's pic at the start of this post that I seek info on. Cheers
Peter TD 5801
P Hehir

These are not 100% correct width and would have to be retapped. Also the holes for the nails are too big and you would have to braise then in.

http://www.displayinnovations.com/product/T-NUT250-20-250/T-Nut-14-20-bag-of-250/
Christopher Couper

OR, make your own.

Top is original, bottoms are shop made out of 303/304 SS.

Jim B.


JA Benjamin

Nice work Jim. A bag of 250? Might be more than I need Chris. :-) I'll have a go at making mine using some rod that I can drill and tap but not sure what to make the base plate out of? Jim can you post measurements of the original and confirm just how many of these were fitted. Was it just one on each floorboard? I assume they are also 1/4" BSF? The one thing that I do miss is not having a lathe for metal work.

The other circular 'T' nuts in that area of the floorboards that are rarely mentioned are the pair that hold the swiveling plate over the master cylinder. These two are definitely 2 BA. See pic showing a brass 2 BA machine screw engaged with an original 'T' nut in situ. Cheers
Peter TD 5801



P Hehir

And don't forget the 4 T nuts for the seat tracks.
Christopher Couper

5/16" BSF. I have them Chris - ready and waiting for the seat installation. Cheers
Peter TD 5801
P Hehir

Abington lists both 1/4 and 5/16

https://abingdonspares.com/collections/bsf-nuts-bolts?page=2

As to when the change. We need more input from the owners. I believe Bill Chaser has one with the later nut system that is in the 4 digits
Bruce Cunha

FTFU has just sent me pic of the 'D" nuts. These are 1/4" BSF, the same as the TC. Cheers
Peter TD 5801


P Hehir

Didn’t know the D nuts were even available retail. Figured I was going to have to make new ones

Bill Chasser
TD-4834
W A Chasser

Thanks for the information for the D nuts Peter!

Frank
TF1414
Frank Cronin

Wow. Those look much sturdier than I would have thought.

Did Doug explain how you are supposed to mount them? Would a whack with a big hammer be enough to peene over the edges?
Christopher Couper

I didn't get into that Chris, but I assume so. As Rod Brayshaw says, "There is a small recess in the panel to equal the hammered part to sit flush with the rest of the panel". I've not seen these FTFU items in the flesh as I only ordered them yesterday. My toe board is bespoke so I'll first have to create the dished shaped recess in the sheet metal. I'll have a better idea when they arrive. Cheers
Peter TD 5801
P Hehir

At least, with the ones I made, you need to start the peening process first.
I used a large ball bearing in the swage end for the first few bangs.

Thinking about it a small ball peen hammer would do.
I would hit it with a bigger hammer, but if your aim is good!

Jim B.
JA Benjamin

Once I have them Jim I'll measure the width of the required depression and use a piece of steel rod at that diameter and my lump hammer to take care of the toe board depression. Not sure about the initial flaring of the nut though, just to get things started. I do like the idea of the large ball bearing. I'll suck it and see. Cheers
Peter TD 580
P Hehir

I could agree with the D nuts being used to get closer to the edge - if the flats were aligned with the edges - but they are not! My guess is that they are to stop the nuts from spinning, the sewage (I did type swages) not being sufficient to prevent this.
My pic shows a sophisticated jig to perform the swage on my home made nuts. Instead of trying to be accurate with a ball pein hammer, put the swage on a bolt head and hit the flat side. Needs three hands but it works. I couldn’t be bothered with recessing the swage, nothing in that area of TF2071 is that precise.
The pointed bolt is my idea for marking the holes in the floorboards. Instead of crawling underneath with a pencil I intend to insert the bolt from below till the point is just above the surface, replace the floorboard then give it a tap with a mallet. This idea came when I found that one of the floorboard/toe board bolts wasn’t a captive D nut but was built into the brake pedal box (RHD) and inaccessible.



C I Twidle

The D nuts arrived from FTFU today. Thanks for the info Chris. I was intrigued to see you state that one of the floor 'D' nuts was a captive in the pedal box. I'll have a poke around there when I'm next at the car. I have a few pics of LHD toe boards but none from a RHD car. Can anyone post some pics of one here showing the captive nut details, locations etc? Cheers
Peter TD 5801
P Hehir

Hi Peter, I can’t guarantee the originality of TF2071 but most of the changes I know about involve different threads. The two captive nuts in the brake box are both 1/4BSF, original? Second pic shows rh end of the toe board has a corresponding cut out.


C I Twidle

I don’t know why my pics are upside down! They appear the right way up on the other forum. Also when I try to add a second pic it simply replaces the first.


C I Twidle

Thanks for the pics Chris. 1/4" BSF is original. No idea why your pics are inverted but you can only post one at a time. A second pic requires a second post. A TD owner is bringing an original toe board for me to photograph and measure at the Tech Day on Sunday. That will enable me to proceed. Cheers
Peter TD 5801
P Hehir

This thread was discussed between 11/05/2018 and 05/11/2018

MG TD TF 1500 index

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