Vehicle towing

[GunnarTM]

The ones I bought were specifically for the towing eyes they are AF threaded and about 25 mm longer than the standard bolts. Blanchards May have them also.

Antarmike replied that 4" BSF (101.6mm) was standard, and I'd need 4 1/2" BSF (114.3mm) to accommodate the tow eye ... 1/2" or 12.7mm longer.

25mm longer would be c. 1", so 5" (126.6mm) total?  I wouldn't mind a bit of screw hanging out the bottom, but running out of screw when the shaft starts would be a nasty surprise.   I found this on the Blanchards site, but it's 4.25 inch; 1/4" is 6.35mm (108mm)  ... 6.4 mm longer.

The mounting plate for the Minerva tow eye is c. 1cm (between 25/64" and 13/32"; let's call it 3/8" or 9mm) ... that's a difference of 6.3mm.

Presumably I'll need new nuts as well ... unless the old ones will fit.

Perhaps I'm overthinking this :-(

[GunnarTM]

This https://pablanchard.co.uk/Bumper-Bolt-was-256254-NRC2384?search=bumper%20bolt

[T28-trakgrip]

This is mine


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[T28-trakgrip]

One over each dumb iron and Bowden cable for braking


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[sam123]

This is how I move Mine, its on A frame with brackets that go over the bumper through the dumb irons to save drilling the bumper

Pulls great behind my pickup, steam engine tractor


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[antarmike]

This is how I move Mine, its on A frame with brackets that go over the bumper through the dumb irons to save drilling the bumper

Pulls great behind my pickup, steam engine tractor


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But not legal in UK, unless you have a method of applying the Land-Rover Brakes.  No trailer without working brakes is allowed to be used if it weighs more than 750 kg.

[sam123]

I see your point but behind a 1902 steam engine that does 5mph and a 1936 tractor that does 10 brakes are the least my worries!


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[gcc130]

But still illegal if you happen to be pulled over.

[GunnarTM]

Okay, I found this one on eBay:  https://www.ebay.de/itm/222616146431?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649  £4.99 + £14.24 shipping = £19.23 or €5.81 + €16.57 = €22.38.

They're 4 1/4", which I hope will work as TAC says, because I can't find any 4 1/2" as Antarmike suggests.  The originals are said to be 4" with some threads visible on the bottom, and I have to bolt on a 1cm (= 0.39") mounting plate, so an extra 1/4" is 6.35mm more.

They're also 3/8 UNF instead of BSF, but also come with nuts.

I hope these work.

P.S.  I stumbled across the following explanation on threads here https://www.mmoc.org.uk/Messageboard/viewtopic.php?t=12918 , which I found illuminating.

"Joseph Whitworth developed the first standardised bolts, and the standard was called British Standard Whitworth or BSW. The standard specified both the thread sizes and the sizes of the bolt heads, so a 1/4" Whitworth spanner is a spanner designed to be used with bolts that have a 1/4" Whitworth thread. The head sizes are rather odd measurements and were chosen based on the strength of steel used for making bolts at the time.

BSW is a bit too coarse (too few turns per inch) for many applications, so British Standard Fine (BSF) was developed. It has a finer thread but uses the same spanners as BSW, so a 1/4" BSW spanner will also work on a 1/4" BSF bolt.

BSW and BSF don't go down to really small sizes, so there was a third standard called British Association (BA) developed for small screws, and they have their own spanner sizes. BA is numbered backwards - the biggest one is size 0, and above about 8 or 9 is very small indeed.

There's yet another standard called British Standard Pipe (BSP) which is used for pipe fittings - the thread form is optimised for screwing together hollow things as opposed to solid bolts. I'm not totally sure what the situation is with the spanner sizes for BSP fittings, as I've seen at least three different sizes used on 1/4" BSP fittings, but I suspect they're supposed to use Whitworth spanners. BSPT is a tapered version of BSP that's used in applications where the thread itself needs to provide a good seal.

I think America had their own equivalents of BSW and BSF (ANC and ANF), but after the Second World War, various people agreed it was a bit silly the way mechanics had had to carry two sets of tools around to work on allied equipment, and they agreed on the Unified Thread Standards (UTS) which included a coarse thread (UNC) and a fine thread (UNF). The bolts which used these threads were to have more sensible head sizes that were common fractions of an inch. AF isn't a thread type, it's "Across Flats" and is just a way of measuring the size of a bolt head, so UNF and UNC bolts have head sizes that are specified by measuring them Across the Flats instead of relating them to the thread size as with Whitworth and BA.

The "new" pair of standards that the whole world is moving over to is ISO metric coarse and metric fine, which use bolt heads that are sensible multiples of 1mm AF."

[Dpaz]

The 'usual' spanners for BSP are usually Adjustable or Stilson pipe wrench (Shifting spanner with teeth). We now also need three sets of spanners. AF, Metric and BEF/Whit.

[Trakgrip]

... a 1/4" BSW spanner will also work on a 1/4" BSF bolt. ...

This is not strictly true, commonly the head on a BSF fastener is one size smaller than the head of the same diameter BSW fastener. For example, a spanner will be marked (and will fit) 1/4"BSW / 5/16"BSF.

In 1924  BS129 defined the British Standard Whitworth (Small hexagon) standard (known as BSWS, or sometimes "Auto-Whit") for which the coarse and fine head sizes matched. In 1940 the standards were revised again as as a War Emergency to reduce steel consumption and this defined the "normal" BSW head sizes to be the same as the earlier BSF sizes, as a result of which BSF, BSW, and BSWS all shared the same head size for a given diameter.

After the war manufacturers seem to have reverted to the original relationship between BSF and BSW head sizes, with the result that the traditional "one step" size difference returned.

Most commonly therefore you will find that you need a spanner marked as in my first paragraph, bit you should be aware that depending on the age of the fastener and the age of the spanner this may not be the case.

There is of course a huge number of other threads which you may come across, such as British Standard Cycle threads, British Standard Brass threads, British Standard Naval threads, and so on. Fortunately usually on vehicle we only have to contend with BSW, BSF, UNC, UNF, ISO metric coarse, and ISO metric fIne. Landrover has always like to mix and match - the front axle of my 2007 TDCi Defender has metric, BSF, and UNF threads at various locations.

[fulltilt]

The 'usual' spanners for BSP are usually Adjustable or Stilson pipe wrench (Shifting spanner with teeth). We now also need three sets of spanners. AF, Metric and BEF/Whit.

The next time you do any plumbing - try your metric spanners on modern BSP fittings  - you will probably find you use 24mm more than any , IIRC 21mm & 23mm are also used.   Older BSP by such as Pegler Prestex fittings up to mid-1970's if they were proper hex. then IIRC they took a Whit/BS spanner.  I have the odd proper Conex spanner (not a hex.  )   the sizes are stamped - they may even be AF.

A few years ago I ripped out a oil boiler & employed a CORGI engineer to install a gas boiler (Indirectly that is he was a subby. for the Gas Supply Company.   He couldn't get it running until I told him he was pumping the flow instead of the return       In the process he determined trapped air in the cylinder and butchered every fitting (they were a special order to me from BSS  and were DZ spec.) Yes - they were Stilson & water-pump plier men            It turned out the CORGI man was a ex-squaddie sponsored through the course (this seems quite common - 6 months training).    I had to tell him that I had never left my name and address on any machine tool in god knows how many years on the tools & if I had  - I would have been sacked..

[Dpaz]

I forgot about water pump pliers and of course  Footprints, often made in the metalwork class at school

[Graeme]

Any chance we could get back to the 'Towing' topic now?

[GunnarTM]

New Bearmach Series 2 4 1/4" bumper bolts arrived today, 1/4" longer than the Series 1 bolts and a perfect mount for the Belgian Minerva tow eye.


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[TAC]

I painted mine with Galvafroid Zinc based paint. It looks much better than the red and fades to nearly match the bumper bar after a couple of months.


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[TAC]

Missing photo


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[GunnarTM]

I painted mine with Galvafroid Zinc based paint. It looks much better than the red and fades to nearly match the bumper bar after a couple of months.

Moments after I thanked the seller on the Minerva Facebook Group for selling and sending me the red one https://www.facebook.com/groups/322603541517578 , another guy popped and said he had them in green (photo attached) 🙁  Arrgh ... that was the color for which I was looking, but the red's starting to grow on me already as it's authentic Minerva 😉

That said, my wife is now agitating for green, black, or zinc.  I think something like this should do the trick https://www.amazon.de/-/en/Liquid-Zinc-125-Tin-Colour/dp/B00MZ8QLQ2/ref=sr_1_12 .

She's also convinced that I'll have to remove it for each TÜV because the tip of the pigtail sticks a smidge beyond the edge of the bumper.  I think it's fine.

Thanks again for all the help on the measurements; the extra 1/4" was perfect.  The towing eye was €15, and the bolts were £5, plus shipping for both but not egregious.

[GunnarTM]

P.S.  I started paying more attention to Minervas of late, and have noticed that the size and/or configuration of these pigtails appears to be as unique as fingerprints!  http://www.exmod.co.uk/Minervas.html

[GunnarTM]

We went with zinc.


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[GunnarTM]

Came out pretty well, in my humble opinion.  Peace of mind should I ever have to be schlepped or winched out without having to improvise and potentially break the chassis paint.  Thanks to all who helped me locate the slightly (1/4") longer Series 2/2a bumper bolts.


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