Thread: Disappearing U-bolts

Originally Posted by 350RRC

I know of people who get double duty out of them by gently tapping the 'cap' on the nylon part with an American screwdriver (my mechanical genius grandfather's name for a hammer).

Works for me, but 'don't try this at home'.

DL

We do that at work on occasions,but on something where they are used as a critical component,we always only use them once.

Crankshaft nut for a flywheel is a good example.
And use a torque wrench.

Yeah, I only do it on the little ones. It's not as if they're expensive.

DL

I use "Nord-lock" washers on trailer suspension U bolts, with Nyloc nuts for added safety. I learnt the hard way after having to rescue a friend a while back when his trailer and axle parted company on one side coming back from Wave Rock to Kalgoorlie on a weekend camping trip. I managed to hold his trailer together with fencing wire for long enough to get it home, and then we fitted all new U bolts with Nord-locks and Nyloc nuts. I never use "spring washers" for anything - they are crap.

I learnt about "Nord-lock" washers while working with crushers for years. The vibration experienced in these machines will shake anything loose - except for Nord-locks. I now always keep a box of various sizes in the shed and still use them regularly. You can get them at any decent fasteners supplier - such as Blackwoods - (I won't use the cheap Chinese copy of these that Bunnings flogs).

https://www.blackwoods.com.au/fasten...38195/variants

I've seen enough broken U-bolts that when I built my camper trailer I was having none of them, came up with a far better solution using clamp plates and HT bolts. 21 years and many thousands of outback km and every time I check them they are still snug.
spring and airbag.jpg

youre on the money here Pod.

as I read further into the thread. I thought why doesnt any one use plates and hi tensile bolts and there you go.

Hello All,

Back in 2019 I bought a brand new dual axle trailer. In my second week of ownership the trailer came to a dramatic stop after the rear axle passenger side U-bolts disappeared and the axle moved backwards onto the chassis. After parking the car and trailer off the side of the highway I walked along the road behind the trailer picking up leaf springs. After I continued the walk further down the road I found one of the U - bolts. It had broken off at a bend where the bolt changed direction. It had pinch marks where the bend must have been forced by a die when it was manufactured. The u-bolt broke off at the pinch. Once I got into town I went to a trailer supplier and all their u-bolts had the same die-formed pinch. I bought a complete set of larger diameter of u-bolts that were a different brand for the trailer - ones without the pinch. The trailer has had no troubles since then.

Kind regards
Lionel

Originally Posted by Lionelgee

Hello All,

Back in 2019 I bought a brand new dual axle trailer. In my second week of ownership the trailer came to a dramatic stop after the rear axle passenger side U-bolts disappeared and the axle moved backwards onto the chassis. After parking the car and trailer off the side of the highway I walked along the road behind the trailer picking up leaf springs. After I continued the walk further down the road I found one of the U - bolts. It had broken off at a bend where the bolt changed direction. It had pinch marks where the bend must have been forced by a die when it was manufactured. The u-bolt broke off at the pinch. Once I got into town I went to a trailer supplier and all their u-bolts had the same die-formed pinch. I bought a complete set of larger diameter of u-bolts that were a different brand for the trailer - ones without the pinch. The trailer has had no troubles since then.

Kind regards
Lionel

X 2
I had the same sort of problems with a small trailer, the Ubolt looked more like a V than a U. I noticed one of the bolts had broken when I had to change a flat. Trailer had done barely a 1k. As I had a round axle I replaced them with a set of "proper" UBolts just from the local hardware store, 15 years later I've not had any problems.

Cheers Glen

For the benefit of anyone else who, like me, had never heard of Nord-Locks, the following video shows how they work.

Nord-Lock Wedge-Locking Washers - Junker Vibration Test - YouTube