Identifying trailer stud thread and pitch for a locking wheel nut

JumbleDuck said:
Most? The only trailer I have ever met like that is the one for my Hunter 490, which has old Rubery-Owen suspension units. The Insdepension units I bought for the Drascombe trailer last year are right hand thread for both sides.
Click to expand...

Indeed, the hubs are generally the same both sides. It's worth being aware of the possibility on the odd ancient trailer.
 
third engines said:
Most trailers use left hand thread on the nearside wheels so standard automotive nut lock would not be suitable.
Click to expand...

JumbleDuck said:
Most? The only trailer I have ever met like that is the one for my Hunter 490, which has old Rubery-Owen suspension units. The Insdepension units I bought for the Drascombe trailer last year are right hand thread for both sides.
Click to expand...

lw395 said:
Indeed, the hubs are generally the same both sides. It's worth being aware of the possibility on the odd ancient trailer.
Click to expand...

I had no idea that left handed wheel nuts even existed. Hub nuts OK, but wheel nuts ???????
 
VicS said:
I had no idea that left handed wheel nuts even existed. Hub nuts OK, but wheel nuts ???????
Click to expand...

I had an old dinghy trailer, with bonded rubber suspension units, split-rim wheels and LH threads on one hub. This was 35 years ago and it wasn't new then, by a long chalk. ISTR some debate around the club bar whether the LH threaded hub was on the wrong side, but it was too long ago!
Indespension units didn't fir the trailer chassis, I remember that clearly as I wanted to swap the units with an old box trailer I had.
 
JumbleDuck said:
Why not remove a nut, take it to Indespension (other trailer parts suppliers are available) and say "Have you got a locking version of this?"

Do thieves steal trailer wheels?
Click to expand...

That's what I shall have to do, but i was hoping to ID the thread/pitch so as to take advantage of online purchases at a good price and above all without having to drive around the countryside taking up a lot of time and effort.

Do they steal wheels- well scrotes certainly do and these wheels are in nice condition and with new tyres, so worth a little effort to protect
 
Gin said:
That's what I shall have to do, but i was hoping to ID the thread/pitch so as to take advantage of online purchases at a good price and above all without having to drive around the countryside taking up a lot of time and effort.
Click to expand...

I dont understand why you cannot ID the thread.

You say you have a vernier caliper
so
Measure the OD of the thread on one of the studs.
If it is a neat round number of mm 8, 10 or 12mm say it will be metric ............ It may well be a fine thread thread though ( my wheel bolts are! ) in which case an ordinary metric nut won't fit it.

You suspect the trailer is of American origin therefore metric is unlikely unless it has been modified

If it matches a fraction of an inch, eg 3/8, 7/16 or 1/2 it will almost certainly be UNF.
Measurement of the thread pitch will confirm ( 24, 20 and 20 tpi respectively for the above )
 
Gin said:
I have a braked, double axle, galvanised boat trailer of about Y,2000 vintage


However, just to further confuse, the trailer has a manufacturers very faded badge which I think says' CM trailers'- an American firm, who I have contacted and they say they have no UK dealers,
Click to expand...

More likely RM Trailers ?????????

Taken over by Tex engineering some years ago but still making boat trailers. .....

A trailer from RM trailers in about 2000 would be likely to have metric wheel studs.
 
Last edited:
colhel said:
From the information given, I'm 90% sure it's an M12 x1.5 . You could check the pitch with a Standard M10 bolt as this would have a 1.5 pitch which you could use as a pitch gauge, ideally on the stud.
Click to expand...

Wouldn't M12 be either 1.75mm pitch or 1.25 mm pitch?
 
Last edited:
VicS said:
Wouldn't M12 be either 1.75mm pitch or 1.25 mm pitch?
Click to expand...

Yes. but the spanner n the works is the 10.3 ID in the nut. Too big for 7/16" , a tad too small for 1.5 pitch but way too small for 1.25.
Be good to find out the answer :)

tapping drill for M12x1.25 is 10.75
M12 x 1.5 would be 10.5?
7/16" UNF is 9.9

Try an M8 bolt to use as pitch gauge, 1.25mm pitch
 
colhel said:
Yes. but the spanner n the works is the 10.3 ID in the nut. Too big for 7/16" , a tad too small for 1.5 pitch but way too small for 1.25.
Be good to find out the answer :)

tapping drill for M12x1.25 is 10.75
M12 x 1.5 would be 10.5?
7/16" UNF is 9.9

Try an M8 bolt to use as pitch gauge, 1.25mm pitch
Click to expand...

Just for comparison I have checked the studs on my other car ( Volvo) but that has bigger wheels than the OPs trailer.

M12 x 1.25 ( well 20tpi as I dont have a metric thread gauge)
 
Problem solved.
The American pedigree was a red herring, which set me off on the wrong foot; further complicated by measuring the ID of only the nut, when I got home, with my vernier;this wasn't helpful as it would have been more accurate to have measured a stud but I couldn't get back to the club until this morning.
A 20 mile detour to the most convenient trailer accessory outlet quickly solved the problem as my nut fitted one of their stock M12, 1.5 pitch studs and they had just one matching remaining M12, 4 nut locking kit left, which I purchased and have now installed.

This was also the cheapest option as it turned out at £10 for the nuts and unique key, so well worth it if only for my peace of mind.

Thanks to everyone who chipped in with ideas and possible solutions- and hats off to 'Colhel' as he was first to suggest the correct thread.

Gordon
 
Thanks for the feed back.


How you going to stop the scrotes undoing the hub nuts and nicking the wheels complete with brake drums, hubs and bearings
 
You must log in or register to reply here.

Other threads that may be of interest

Refueler
Bow winch eye ...
2
Replies
20
Views
366
Refueler
Refueler

Share this page

Top