TR2/3/3A TR3 windscreen frame corner bracket screw thread

[71TR6]

Hello-
While rebuilding my TR3A windscreen, I twisted off a couple of screw heads that are used to secure the L-brackets that connect the main windscreen frame to the bottom frame piece. I plan to drill out what’s left of the screws and retap the holes. The thread OD of one of the screws I was able to extract looks to be 0.152”. I tried threading an 8-32 into one of the threaded holes in the bracket and it didn’t want to go in. I had a 2BA screw laying around and it is too large as well.

Does anyone know for certain what the thread type and size is for these screws?

 

[bobhustead]

Moss lists a replacement kit under part #802-675
Bob

 

[71TR6]

Hi Bob,
Thanks for he quick response. I’m aware the brackets are available, but I’m trying to avoid spending $40 if I only need a couple of screws.

Ron

 

[CJD]

All those screws are whitworth.

 

[71TR6]

Thanks John. That helps get me started.

Ron

 

[sp53]

Those screws yeh, anyways they are so small and hardly any threads to work with. I did get some small local screws that were close and filled and ground the fit. I believe they are only about to 1 or 2 full turns going into frame and they had to pass through the rubber and small sheet-metal piece. Originals probably would be better, but those guys often disappoint me with their small stuff.

steve

 

[CJD]

Oh, it just dawned on me that you are talking about the little L brackets. I think those are self tapping...and the kits use some small SAE thread, although I suspect the originals were Whitworth. Drilling them out is tricky, as the frame is chrome plated brass, so the screw material is harder than the frame it threads into. I would recommend drilling out the old threads, and then make the best you can with self tapping screws that will bite into the hole that's left.

 

[sp53]

Oh I think I had it wrong and John had it correct the first time. Those little beveled head screws are maybe SAE, but I am not sure. They are small and stubby and once you have the L bracket out you can see what you need if the threads are there. I have drilled off the heads and pulled the frame away, but I think I bought new L brackets with the little screws, or maybe I re- taped them.

steve

 

[DavidApp]

I think I have a new pair of "L" brackets. I will check in the morning to see if I can get the thread size.

David

 

[DavidApp]

I can tell you what the threads are Not.
Not 10-32 or 8-32
Not BA.
The thread is 0.150" diameter. could not get the thread pitch. Old eyes and a very short screw.

Interestingly in the kit there are 4 screws. 3 ate slot and 1 is Philips head. Both kits are like that.

David