Odd shape on under surface of Surrey top

[MichaelH]

Hi All you surrey top fitters

Got a friend who can't fit his "original" surrey top back light to the TR4 he is building up because it has lumps on the underside

Any information or ideas or opinions as to significance of these lumps and what to do to fit the back light to his car?

Thanks in advance

Michael H

 

[Rob Salisbury]

Hi, Just checked on the original frame I have in the loft, that shape should be there (one lump on each forward facing section) ... so long as the rear deck is correct then these don't interfere, so something else may be out of line.

Cheers Rob

[Motorsport Mickey]

I've looked on my original backlight...and no sign of them. Consistent rear deck height bolt points with nothing in between...maybe alloy casting flow points not cleaned up ? Where's the angle grinder with cutting disc ?

Mick Richards  

[MichaelH]

Thank you Rob

Confirms that these are original

Maybe something to do with the forward arms of the H piece which are different in the 4s compared to the 4A/5/6

I suspect that they will just need to be gently removed as Mick suggests

MichaelH

[stuart]

12 hours ago, MichaelH said:

Thank you Rob

Confirms that these are original

Maybe something to do with the forward arms of the H piece which are different in the 4s compared to the 4A/5/6

I suspect that they will just need to be gently removed as Mick suggests

MichaelH

The 4/4a difference in forward deck extensions makes no odds to the frame fit but to fit the frame to a waisted 4a one you do need to delete the forward studs as they interfere otherwise. Ive not seen those lumps under the frame  so possibly deleted on later pressings.

If that frame has the original glass can you check the date on it as its possibly a 61 (so very early) frame. Look at where it says "Toughened" on the glass and look for a dot under one of the letters as that corresponds to the year of the glass  so T-1 O-2 U-3 G-4 H-5 E-6 N-7 E-8 D-9

Stuart.

[stuart]

Looking again at the picture in the OP that lump seems to be right where the deck extensions joint with the rear deck comes up, how is that joint finished if the deck extensions have been replaced? I spot weld them together then lead the joint and put the line back in after with a body file, this stops cracking of the paint as well as making a weather proof joint but care must be taken to not to enlarge the area,

Stuart.

 

[Revival Motorsport]

You've probably already dealt with this now, but those lumps on the underside show that the frame was originally for a 4A or 5. They're only there to stop the trim panels flapping about. To fit a later frame to a 4, you'll need to grind the lumps off. The only other differences between a 4 frame and a 4A/5 is that the later frames have longer studs in the first position aft of the B post. These studs, instead of going through the deck (like on a 4), slide past the deck in this area and would originally have had a folded steel bracket that hooks under the lip of the deck. 

[stuart]

11 hours ago, Revival Motorsport said:

 the later frames have longer studs in the first position aft of the B post. These studs, instead of going through the deck (like on a 4), slide past the deck in this area and would originally have had a folded steel bracket that hooks under the lip of the deck. 

Really? Never come across this.

Stuart.

[Revival Motorsport]

55 minutes ago, stuart said:

Really? Never come across this.

Stuart.

Yep. I had to research this when reproducing the back light frames. A local contact and life-long TR enthusiast has a very rotten but totally original TR5 in his workshop, so I went to take a look. It was parked up with something like 30k on it, 40 years ago and has never been apart. The hard top was fitted from new. 

Ben