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MG TD TF 1500 - Convertible top posts barely fit

If you look at the picture, you can see that the two wingnuts that screw in to windshield posts, which lock the convertible top down, don't fit very well. They are so far out on each side that when tightened down there is a real possibility that the whole thing might pop open at speed (I think).

I'm not sure how this happened (just bad fitting from the factory, possibly) but the screws just slide to the left and right of the two posts. As you tighten down, the metal frame itself bows a bit, allowing the screws even more room to pop off under pressure.

A PO drilled a hole on the left side, which might have been for another screw in a desperate attempt to keep the frame from flexing any more, to keep the top on.

At any rate, you should see from the images below that it's a pretty weak fit.

But the only solution I can think of would be to take everything apart, cut the frame in the middle and reweld it, taking 1/8 inch out so that the screws match the posts better. I can do this, but for obvious reasons (including the fact that the canvas will hang more over the sides) am reluctant to... but I really can't think of any other solution. Suggestions?

I could do what the PO did and add wood screws to the far left and right edges, an inch in from the side, to keep the edge of the frame from bending as you turn the screw into the post; but I don't think that would work well and would be very likely to crack or damage the wood in a short period of time.

Suggestions?


Geoffrey M Baker

Geoff,
I think you are also missing the Copper inserts that line the holes in the wood. At least they do on the TD.

Just a thought - are the posts bent in towards each other?

Rod.

Moss
90a 406-920 $5.75 SOCKET (in header rail) 2

Rod Jones

Rod, I know I am missing them; I wasn't really thinking about them only because from what I've read most people don't use them (the Schach book says he doesn't use them because they won't fit). But thanks for noticing; it might be worth getting a set.
Geoffrey M Baker

Geoff,
No matter what - the screws in the hood frame should line up with the windscreen posts. Those liners I think were there to protect the ash the also take up some of slack space around the post to make it more of a fit. It is important to have everything on line thought or it is all a moot point.
The hood frame IF it came with the car from the factory should be right if strait and not damaged.
I just measured my TD screen and hope this points you in the right direction. There is really no adjustment on the posts laterally but they could be bent I guess?
My screen top came out at 39 1/16"
Posts are 9/16" from the edge.
Rod



Rod Jones

I'm sure you are right, Rod, but there is no way of knowing. This car's history is clean back to the 1970s but before then at some time it was completely repainted including the engine and got a new aftermarket top. Maybe it was in an accident and someone matched another convertible frame to the windshield, or replaced the windshield, who knows. My posts are not bent, and look fine; it is the convertible frame assembly that I suspect is wrong. It has a weld in the middle of the front bar (maybe all of them did?) already.
The front bar fits to the ash header rail OK, but I'm sure it has been bent many times. As I say, someone put a hole in the left side, clearly to add a screw in the hopes of keeping the frame from bending when screwing the thumbscrew into the windshield post... which it does....
My windshield top measures the same as yours, as do the post positions.

Looks like cutting/rewelding still looks like my best option...
Geoffrey M Baker

If you have a flaring tool and a short length of 1/2 inch copper water pipe you can make those sockets in a short time (1/2 hour). Before Moss had them I made mine and gave many away to others for their tops.
F. Driver

Got to agree with that.
The wood and the windscreen are correct. Then the hood frame must be the culprit.
I would not worry about the width of the hood as it must fit the windscreen and from your pics it is too wide anyway. Just get the screws to come in through the wood to engage the center of the posts and you should be golden.
Good luck - let us know how it turns out.
Rod

Rod Jones

I had the same problem on my TF, I cut the frame at the original weld, adjusted the frame length and tack welded it in insitu after doing the following.

The connection onto the windscreen posts are primitive to say the least. I fabricated thin flat plates with a pipe insert welded into them, I then screwed the plates to the ash header. All this is hidden under the hood covering.

Make sure you protect everything with wet rags when you do the welding.

The pipe inserts have to be drilled to coincide with the angle of the attachment screws meeting the pegs.

Providing the header is located with downward pressure so the attachment screws align with the flats on the pegs the hood is totally secure.

From the mess the original ash header was in I believe this fault existed from the time of original assembly.
G Evans

Nice mod Graeme. Did you let the plates into the timber or was it not necessary? I think I'll do the same when I get that far. On the corner posts I bought new repros from Moss through Sportsparts in Sydney which I had to throw in the bin. The post wasn't far enough from the corner which meant that the top & side windscreen pieces were about 8mm out of whack when assembled. As I'd drilled & tapped them before I discovered they were useless, they couldn't be returned, so I copped it on the chin & had the originals repaired & rechromed. Useful post Geoff. I now fully expect to have to do the same. Should save some blue language. Forewarned is forearmed... Cheers
Peter TD 5801
P Hehir

Geoff, what about a different alternative. The wingnuts go into a cilindrical threaded part. Looking at the pictures , it appears that the angle by which these cilindrical parts are welded to that flat strip, only would have to change a little bit to allow the wingnut tip to end correctly. With a thin ( 1 mm ) flat grinder or even a metal saw, i would cut this cilindical part more than halfway just above the flat strip. But leave them in place for convenience. Than bent that cilindical part into the wanted angle and do some welding (slow to avoid too much shrinking). Huib
Huib Bruijstens

G Evans, do you have any pix? Sounds like a good mod... Huib, I think that is beyond my skills... I'll cut and reweld the front bar, it will solve the problem
Geoffrey M Baker

Huib, thinking more about your post, that might well work. Only problem I can see is that rewelding would have to avoid filling in the threaded screw hole... hmmm...
But I still think just cutting the bar is the easiest fix. The width of the two sides is relatively unimportant (the convertible top is sized to fit over the side curtains, not the front part of the frame assembly) and could also be bent easily to bow it out a little if need be. So losing 1/8 or 3/16 of an inch (about 2-3mm) would solve the post problem without affecting the convertible sizing in any way.
Lastly, by trying to change the angle of the wingnut screws, you might end up making it harder to tighten them, as they are angled out to make it easy to adjust. If they were at a 90 degree angle, you'd mash your fingers on the side of the frame trying to adjust them.
If I get time today I'll disassemble the header (now I regret wrapping the canvas on it) and take out the screws and use epoxy to fill the screw holes (as they will all move slightly and will need redrilling), then cut and weld the bar. I'll post pix.
Geoffrey M Baker

Geoff,
One thing I noted on my posts - there is a small hole that the point of the threaded locking screw goes into. It really makes it secure. From the picture above it looks like the post is hollow? There is no way the screw can slip past the shallow notch in the post. It does require that the post and the screw line up pretty well though.
The face of the post with the notch is angled to meet the screw anyway from the look of it. So, as you said, you don't mash your fingers on the side frame when doing it up.
Rod
Rod Jones

Rod, you must have a later model or a Moss aftermarket post; mine have no holes.
Geoffrey M Baker

Ok, I cut and rewelded the bar. Took three goes to get it right, but it all now fits. I also bought the brass inserts Moss sells for the windshield posts and as others have noted, they are really too big to be of much use. I had to file out the holes on the metal plates on the underside of the ash header piece to get them to fit, and that was after grinding and rebending the brass inserts to make them considerably smaller. All in all, not worth doing.
I am considering making up my own out of steel or brass, that would be a tighter fit on the posts.
Anyway, here are pictures of the process of redoing the bar and how it now fits. Sorry for the reflection, but you should be able to see that the posts and wing nuts are now a much better fit!

Geoffrey M Baker

And here is how I jigged the frame up and cut about 3/16 out of it. I then gently tapped on either side to bring the pieces back together, and welded them.

Geoffrey M Baker

Well Geoff, I did not make the holes and the posts have been there since 1974 (under my care). I can only assume the sharp point on the screw has formed these holes, as I do tend to crank on the screw. Since I don't want the hood to fly open whilst driving. Which it has never done. It is comforting to know however it is seated really well in the post.
It could also have been the previous owner. as I can't remember ever looking at them till your post. LOL
Rod

Rod Jones

Rod, I can see from the picture that your posts are hollow, with a hole drilled to "catch" the thumbscrew. Mine are not. I don't know why... but it could be a change in TD model; mine is a 51, maybe they changed to a hollow post for 52?
Mine is not to reason why, but to accept the fact that no two TDs are ever alike... :)
Geoffrey M Baker

This thread was discussed between 14/10/2014 and 16/10/2014

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