Classic cars forum & vehicle restoration.

[Bayliss Thomas]

I need to find an engineering shop that will be able to drill/ream out the towing eye on my vintage caravan drawbar. I do not want to remove the drawbar from the caravan as it is a nightmare job to bolt the thing back into place.
I have a new towing pin which is 19mm and the tow eye is about 17mm. If somebody can offer me a link as to who may be able to drill this out please. I live in Diss, Norfolk, so nearer the better. Thank you.

[Uncle Alec]

Plenty of 18.5mm HSS drill bits and 19mm reamers on eBay.

[Bayliss Thomas]

Thanks Uncle Alec, ordered two 20mm HSS drill bits (blacksmiths type) which the shank will fit my DIY drill chuck. Panic over.

[Uncle Alec]

At the risk of teaching Granny to suck eggs:

Ensure the eye is held totally rigid before drilling.
Plenty of suitable lubricant - the aerosol cutting oil from Screwfix I find handy.
I would have bought 19.5 drill and a 20mm reamer, but it depends on how clinically accurate the hole has to be - I suspect not very.
All this assumes that the steel is drillable. Probably, given the age of the eye.

[Penman]

Hi
Those sizes sem to be quite small, I have a book/catalogue from Indespension and it has a couple if info pages about towing eyes and all it mentions are 30,40,50 and NATO 76mm sizes. it also has diagrams showing correct fitting size of throat etc.

I know taking 3mm out only reduces the thickness of the ring by about 1.5mm but is there a danger of it weakening the ring too much?
_________________
Bristols should always come in pairs.

Any 2 from:-
Straight 6
V8 V10

[Uncle Alec]

The "new" pin is probably ¾"; quite a common pin size pre-war.
The "old" hole could be ½" but worn a bit?
If the tow eye is anything like normal it will be at least ½" section hopefully, so no worries there.

[Bayliss Thomas]

Thank you for good advise and comments.The tow draw bar is original fitted into a new steel chassis (25 years ago). Measured up and I will be leaving 17 /18mm of steel surrounding the tow eye after drilling out for new pin. The thickness/depth of the metal part of the tow eye is 9/10mm and seems to be extremely solid.
My caravan weighs in at about 3/4 ton and the new draw bar tow devise I have purchased to fit onto my car is rated at 1.5 ton.

The new pin that came with the tow ball/pin/jaw combined is 19mm. Again thank you for advise / comments.

[Jim.Walker]

Surely, in view of the age all parts would have been manufactured to Imperial Measurements?
Why introduce Metric dimensions?
Jim.
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[Uncle Alec]

I guess he has bought a new tow hitch with removable pin. They are available only in metric as far as I know.

[Bayliss Thomas]

[Jim.Walker]

[welshrover]

[Bayliss Thomas]