It could be the coupling not fitting correctly and being too tight on the ball. You will need to have the ball and coupling checked by a competent person.
Another reason to consider DO35/45 coupling.
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Possum; AKA:- Ali El-Aziz Mohamed Gundawiathan
Sent from my imperial66 typewriter using carrier pigeon, message sticks and smoke signals.
Hi
Get some large stillsons hold the ball tight or lock on to the ball so it wont spin and lock nut on with large shifter or better still torque wrench up to 140 nm.
Also using another nut on thread and locking them together will fix your problems
Cheers
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John
2017 dmax lovells upgrade full CSM trade aluminium canopy,3.5 m quintrex tinny and rear boat loader mangrove jack aluminium trailer
And when you do up the nut, turn the shank 90deg and reinsert it. Then the thread of the shank is parallel to the ground and you can put bodyweight on the spanner. Much better than trying to pull horizontally.
Put the tongue in rotated 90deg the other way to undo. You can then jump up and down on the spanner to release the nut.
I agree the most probable cause of the nut not fully tightening on the tongue is that the tongue is too thin for the depth of thread, leaving the nut tightening up against the end of the thread on the shank.
Add a washer two under the spring washer. NEVER add a washer under the ball itself though.
Never experienced that in all our travel. Maybe some lube on the ball so the hitch doesn't bind. Maybe an adjustment on the locknut to the hitch has a bit of free play. I'd insert the ball in the hitch prior to install and see what it feels like.
As a last resort, Loctite.
-- Edited by deverall11 on Monday 16th of January 2023 11:40:25 AM
Hi Bob, Just out of curiosity have you checked the shank for how much of the non threaded section protrudes down and into the spring washer?
It might be a case that you are tightening up against the end of the thread.
Tim
Great suggestion! Simply put a flat washer on top of the spring washer to solve that problem!
The idea of turning the shank in the receiver also is a good one, as would be the use of a piece of galvanised pipe, or similar, on the spanner handle to give more leverage.
OR, you could do the sensible thing, as Possum suggests, and fit a DO35. Cheers
Have you thought of using a torque wrench and applying the correct amount of torque to the retaining nut.
Torque wrench is of no use if the problem is that there is not enough thread, and the nut is running out of thread. However, from my experience, swinging on a 2' pipe over a power bar torques things up quite nicely, thankyou! No idea about ft/lb or NMs or whatever though. Cheers
On an old draw bar & horse float . We had a dowel about 6mm into draw bar . On another there was a flat area on seat of ball and theres was a welded plate . Both prevented ball from turning! From memory was about 60mm nothing else fitted!! Was quite dangerous if we fitted to smaller ball !
1 check the ball adjustment bolt on the van coupling.
2. buy a 1 15/16" (one and fifteen sixteenth inch) impact socket and you can torque that bugger up tighter than a fishes @nus. Minimum to 250 newtonmeters.
-- Edited by Hylife on Tuesday 17th of January 2023 04:44:51 PM
-- Edited by Hylife on Tuesday 17th of January 2023 04:46:34 PM