Page 1 of 2
Door hinge screws
Posted: Sat Apr 09, 2022 9:15 am
by islecastle
I need to adjust my door fit - 1967 convertible. The countersunk screws that secure the hinges on my car are allen screws. The socket is between 5 and 6 mm, which looks far too small for the size and tightness of the screw. An ordinary allen tool is useless, so I found an impact driver bit that was a tight fit, but still wouldn't shift the screws.
Does anybody know what the correct screws were.
Any suggestions for shifting the allen screws. Drilling out may be the final solution.
Dave
Re: Door hinge screws
Posted: Sat Apr 09, 2022 10:11 am
by ManyMinors
That is bad luck
I've no idea why people want to change things. The correct parts are available. I attach a picture of the standard arrangement. If you cannot get the allen screws out then I suppose drilling and re-tapping will be the only answer but I'm surprised that even an impact driver won't do the job. The original thread was 5/16BSF.
Re: Door hinge screws
Posted: Sat Apr 09, 2022 1:33 pm
by islecastle
Many thanks MM.
I think my next step is to obtain a good quality impact bit othe correct size, and have a go with that before drilling out.
Dave
Re: Door hinge screws
Posted: Sat Apr 09, 2022 4:08 pm
by ManyMinors
I agree. That sounds the best plan.
And then purchase some new fixings.
Re: Door hinge screws
Posted: Sat Apr 09, 2022 9:51 pm
by Sleeper
" The socket is between 5 and 6 mm, " , probably imperial 7/32" or 3/16" , thread size 5/16 BSF.
John ;-)
Re: Door hinge screws
Posted: Sun Apr 10, 2022 8:47 am
by Grumpy21
My doors are slightly mis-aligned and have attempted to remove the lower screws (not hex head bolts) to attempt to make an adjustment.
However all 4 screws are solid and without removing the door completely I can see how I could get access with an impact driver.
I assume Iād need to unbolt the door before I could free off the screws?
Re: Door hinge screws
Posted: Sun Apr 10, 2022 9:04 am
by kennatt
I believe that most of the adjustment is via the hex bolts,I would leave the others alone. They can be a pig to get out after all the years they have been there,you could give yourself a load of agro even getting them tight enough on refitting,and if you strip the threads on the other end (inside the frame) even more so.
Re: Door hinge screws
Posted: Sun Apr 10, 2022 9:05 am
by kennatt
I believe that most of the adjustment is via the hex bolts,I would leave the others alone. They can be a pig to get out after all the years they have been there,you could give yourself a load of agro even getting them tight enough on refitting,and if you strip the threads on the other end (inside the frame) even more so.
Re: Door hinge screws
Posted: Sun Apr 10, 2022 9:08 am
by islecastle
Sleeper wrote: āSat Apr 09, 2022 9:51 pm
" The socket is between 5 and 6 mm, " , probably imperial 7/32" or 3/16" , thread size 5/16 BSF.
John ;-)
Ta for that. Is the Allen key size based on "across flats"?
Re: Door hinge screws
Posted: Sun Apr 10, 2022 9:15 am
by philthehill
Imperial Allen keys are measured across the flats.
As regards replacing the screws with Allen screws - fitting the Allen screws to me is a much better option than using the cross head screws originally fitted. With the Allen screws you have a much better location for the extractor tool. The NOS hinge screws I have are PZ3 cross slotted. A PZ3 screw driver is a poor fit into the cross of the screw. A PH3 screwdriver is a much better fit into the cross. The screw drivers used to test the fit were new Britool screw drivers.
If given a choice I would replace all bolts/screws with Allen bolts/screws every time.
Making sure that the screw threads are smeared in copper grease before fitting helps in any future extraction.
Re: Door hinge screws
Posted: Sun Apr 10, 2022 9:45 am
by islecastle
philthehill wrote: āSun Apr 10, 2022 9:15 am
Imperial Allen keys are measured across the flats.
As regards replacing the screws with Allen screws - fitting the Allen screws to me is a much better option than using the cross head screws originally fitted. With the Allen screws you have a much better location for the extractor tool. The NOS hinge screws I have are PZ3 cross slotted. A PZ3 screw driver is a poor fit into the cross of the screw. A PH3 screwdriver is a much better fit into the cross. The screw drivers used to test the fit were new Britool screw drivers.
If given a choice I would replace all bolts/screws with Allen bolts/screws every time.
Making sure that the screw threads are smeared in copper grease before fitting helps in any future extraction.
Ta for that Phil.
Re Allen versus PZ type, it strikes me that a 3/16" af allen key is a bit on the small side for a 5/16" screw that will probably be well rusted in by now.
Anyway, I'll carry on with the impact tool till either the bit breaks/distorts or the socket becomes enlarged/distorted.
Re: Door hinge screws
Posted: Sun Apr 10, 2022 9:57 am
by philthehill
If you use good quality Allen screws of a tensile strength of 10.9 (min) there should be no problems with the size of the Allen key.
The tensile strength should be marked on the head of the screw.
Make sure that you have well soaked the screw in release oil. I can recommend Plus Gas.
When you have removed the screws I would run a tap through the threads to clean them up.
Re: Door hinge screws
Posted: Sun Apr 10, 2022 11:32 am
by islecastle
Thanks Phil. Point taken about the tensile strength of Allen screws, but if I manage to get the old ones out, I think I will go for the original type.
Dave
Re: Door hinge screws
Posted: Mon Apr 11, 2022 8:21 am
by Grumpy21
I assume the hex bolts fit through elongated holes in the A post into some sort of plate behind the A post. If I remove all the bolts will the plate drop and become inaccessible?
Re: Door hinge screws
Posted: Mon Apr 11, 2022 9:01 am
by ManyMinors
The threaded plates are held in a cage to stop them disappearing into the pillar. That is the theory. There is a possibility on an old car that the cage has corroded away and the threaded plate could slip away but this is unlikely unless your car has suffered considerable corrosion. As a precaution, once you have some of the screws removed, you could push a length of welding rod - or even a threaded bar or something through the hole where you removed the screw from and into the threaded plate to hold it in position.
Re: Door hinge screws
Posted: Mon Apr 11, 2022 9:31 am
by Grumpy21
brill - lost one in an MGB many years ago and it was a nightmare to get back into position
cheers
Re: Door hinge screws
Posted: Mon Apr 11, 2022 11:24 am
by panky
I had a suspiciously loose plate so before I took the door off I drilled and tapped the plate through the 'A' pillar and held it in place with a small button head screw. Once the door was back on the screw could be removed and the hinge position adjusted.
Re: Door hinge screws
Posted: Mon Apr 11, 2022 11:58 am
by Sleeper
Self-tapper ?
John ;-)
Re: Door hinge screws
Posted: Mon Apr 11, 2022 12:22 pm
by panky
No not a self tapper, the plate is a bit too thick but would probably work if you could get it to bite. I used, I think, a 5mm button head as that was the tap size and screw I had to hand and it was nice an neat.
Re: Door hinge screws
Posted: Mon Apr 11, 2022 1:16 pm
by Grumpy21
Good idea, in the V I presume