Door hinge screws

Discuss Bodywork problems here.
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
islecastle
Minor Friendly
Posts: 40
Joined: Wed Dec 01, 2021 10:19 am
MMOC Member: No

Door hinge screws

Post 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
1973 Ford Cortina Mk3
1967 Morris Minor 1098 Convertible
1978 MGB GT
2000 Mercedese Benz SLK 230K
ManyMinors
Minor Legend
Posts: 2752
Joined: Tue Nov 11, 2014 9:41 am
MMOC Member: No

Re: Door hinge screws

Post by ManyMinors »

That is bad luck :cry: 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.
Attachments
Door hinge.JPG
Door hinge.JPG (146.8 KiB) Viewed 922 times
islecastle
Minor Friendly
Posts: 40
Joined: Wed Dec 01, 2021 10:19 am
MMOC Member: No

Re: Door hinge screws

Post 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
1973 Ford Cortina Mk3
1967 Morris Minor 1098 Convertible
1978 MGB GT
2000 Mercedese Benz SLK 230K
ManyMinors
Minor Legend
Posts: 2752
Joined: Tue Nov 11, 2014 9:41 am
MMOC Member: No

Re: Door hinge screws

Post by ManyMinors »

I agree. That sounds the best plan.
And then purchase some new fixings.
Sleeper
Minor Legend
Posts: 1045
Joined: Tue Nov 08, 2016 3:18 pm
Location: Manchester ( Damp and Miserable ) and that's just the wife...
MMOC Member: Yes

Re: Door hinge screws

Post by Sleeper »

" The socket is between 5 and 6 mm, " , probably imperial 7/32" or 3/16" , thread size 5/16 BSF.

John ;-)
Grumpy21
Minor Fan
Posts: 255
Joined: Fri Jan 01, 2021 10:00 am
MMOC Member: No

Re: Door hinge screws

Post 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 I’d need to unbolt the door before I could free off the screws?
kennatt
Minor Legend
Posts: 2625
Joined: Fri Feb 02, 2007 9:11 pm
MMOC Member: No

Re: Door hinge screws

Post 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.
kennatt
Minor Legend
Posts: 2625
Joined: Fri Feb 02, 2007 9:11 pm
MMOC Member: No

Re: Door hinge screws

Post 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.
islecastle
Minor Friendly
Posts: 40
Joined: Wed Dec 01, 2021 10:19 am
MMOC Member: No

Re: Door hinge screws

Post by islecastle »

Sleeper wrote: Sat 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"?
1973 Ford Cortina Mk3
1967 Morris Minor 1098 Convertible
1978 MGB GT
2000 Mercedese Benz SLK 230K
philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: Door hinge screws

Post 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.

islecastle
Minor Friendly
Posts: 40
Joined: Wed Dec 01, 2021 10:19 am
MMOC Member: No

Re: Door hinge screws

Post by islecastle »

philthehill wrote: Sun 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.
1973 Ford Cortina Mk3
1967 Morris Minor 1098 Convertible
1978 MGB GT
2000 Mercedese Benz SLK 230K
philthehill
Minor Maniac
Posts: 10767
Joined: Thu Jul 19, 2012 12:05 pm
Location: Hampshire
MMOC Member: Yes

Re: Door hinge screws

Post 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.

islecastle
Minor Friendly
Posts: 40
Joined: Wed Dec 01, 2021 10:19 am
MMOC Member: No

Re: Door hinge screws

Post 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
1973 Ford Cortina Mk3
1967 Morris Minor 1098 Convertible
1978 MGB GT
2000 Mercedese Benz SLK 230K
Grumpy21
Minor Fan
Posts: 255
Joined: Fri Jan 01, 2021 10:00 am
MMOC Member: No

Re: Door hinge screws

Post 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?
ManyMinors
Minor Legend
Posts: 2752
Joined: Tue Nov 11, 2014 9:41 am
MMOC Member: No

Re: Door hinge screws

Post 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.
Grumpy21
Minor Fan
Posts: 255
Joined: Fri Jan 01, 2021 10:00 am
MMOC Member: No

Re: Door hinge screws

Post by Grumpy21 »

brill - lost one in an MGB many years ago and it was a nightmare to get back into position

cheers
panky
Minor Legend
Posts: 1994
Joined: Wed Aug 20, 2014 4:12 pm
Location: Cheshire
MMOC Member: No

Re: Door hinge screws

Post 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.
Image
Sleeper
Minor Legend
Posts: 1045
Joined: Tue Nov 08, 2016 3:18 pm
Location: Manchester ( Damp and Miserable ) and that's just the wife...
MMOC Member: Yes

Re: Door hinge screws

Post by Sleeper »

Self-tapper ?

John ;-)
panky
Minor Legend
Posts: 1994
Joined: Wed Aug 20, 2014 4:12 pm
Location: Cheshire
MMOC Member: No

Re: Door hinge screws

Post 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.
Image
Grumpy21
Minor Fan
Posts: 255
Joined: Fri Jan 01, 2021 10:00 am
MMOC Member: No

Re: Door hinge screws

Post by Grumpy21 »

Good idea, in the V I presume
Post Reply