Hi everyone.  I have just seen photos of the bolt and nut that broke off while a friend of my niece were towing their Offroad trailer.  I have asked for permission to post the photos so until I get that here is the info.

The vehicle used was a new Mahidra ScorpioN.  Caravan was a Off road trailer/caravan.  In this case

a Drop plate was used as a  lift plate to lift the towball rather than to drop it because the ScorpioN was towing lower than a general bakkie.

One of the bolts that was used to secure the "Lift Plate" to the towbar broke off.  Lucky for him only one broke not both of them at the same time. He could have lost his total caravan.

Reason for the bolt that broke is that it was a normal mild-steel 4.4 bolt and nut that was used to secure the plate to the towbar.

Please ladies and gentlemen check your vehicles properly when you take the vehicle to a place to work on.

And if you are not a technical orientated person get a friend to check up on the work that was done.

Leon, thanks for advising. This is a very good point for those who are not sure or aware of the bolt requirements. 

Hoeveel gat drop plate was dit Leon? Ek dink hoe meer gate jy gebruik, hoe meer spanning op bolts....veral met stop en wegtrek

Relaxed Camper wrote:

Hoeveel gat drop plate was dit Leon? Ek dink hoe meer gate jy gebruik, hoe meer spanning op bolts....veral met stop en wegtrek

Dit was 'n vier gat drop plate.  (Vier gate onder mekaar).  So ja 'n redelike lengte plaat, maar ek het hulle al aan die onderkant van Toya bakkies ook gesien.

In die geval het die een bout totaal afgebreek en het die plaat skeefgedraai op die tow bar waar hy by die ander bout  gepivot het.

Dis maar net geluk dat beide boute nie af gebreek het nie.

and this is how AI word it, I full agree with the AI information with my limited knowledge [PhD, MBA, MSc]

1. SABS/NRCS Approval: The drop plate must be SABS-approved (South African Bureau of Standards) and ideally approved in conjunction with the specific towbar it is fitted to.
2. No Generic Plates: There is no legal option for a "generic" drop plate with generic towing capacities.
3. Vehicle Type Approval (Post-1998): For vehicles registered after 1 August 1998, the entire towing system (towbar and attached accessories) must adhere to approved specifications.
4. Height Standards: When the vehicle is fully loaded, the tow ball height must generally be between 350mm and 420mm from the ground.
5. Engineering Integrity: Modifications (like welding or homemade plates) are risky and can result in insurance claims being rejected. 

• Grade: Grade 8.8 High Tensile Bolts are the standard requirement, though some heavy-duty applications may require Grade 10.9.
• Size: Generally, M16 x 76mm (or similar length to fit the plate and washer) is used for standard 50mm tow ball connections.
• Nut Type: High-tensile, nylon-insert lock nuts (Nyloc) are recommended to prevent loosening due to vibration, though they should not be reused once removed. 

• Two-Bolt vs. Four-Bolt: Attaching a drop plate to a standard two-bolt flange towbar is considered dangerous and illegal by many, as it is not designed to handle the increased leverage and strain.
• Insurance: If a non-approved or improperly installed drop plate is involved in an accident, insurance companies may reject the claim.
• Support: It is highly recommended to use a drop plate that has additional supports (trapezium supports) connecting back to the main chassis mounting points to prevent the plate from bending. 

Swanie wrote:

and this is how AI word it, I full agree with the AI information with my limited knowledge [PhD, MBA, MSc]

Legal Requirements for Drop Plates in South Africa

1. SABS/NRCS Approval: The drop plate must be SABS-approved (South African Bureau of Standards) and ideally approved in conjunction with the specific towbar it is fitted to.
2. No Generic Plates: There is no legal option for a "generic" drop plate with generic towing capacities.
3. Vehicle Type Approval (Post-1998): For vehicles registered after 1 August 1998, the entire towing system (towbar and attached accessories) must adhere to approved specifications.
4. Height Standards: When the vehicle is fully loaded, the tow ball height must generally be between 350mm and 420mm from the ground.
5. Engineering Integrity: Modifications (like welding or homemade plates) are risky and can result in insurance claims being rejected. 

 

Specified Bolts for Drop Plates

To ensure the high shear stress on a drop plate is managed, only high-tensile hardware should be used.

• Grade: Grade 8.8 High Tensile Bolts are the standard requirement, though some heavy-duty applications may require Grade 10.9.
• Size: Generally, M16 x 76mm (or similar length to fit the plate and washer) is used for standard 50mm tow ball connections.
• Nut Type: High-tensile, nylon-insert lock nuts (Nyloc) are recommended to prevent loosening due to vibration, though they should not be reused once removed. 

 

Key Safety and Liability Considerations

• Two-Bolt vs. Four-Bolt: Attaching a drop plate to a standard two-bolt flange towbar is considered dangerous and illegal by many, as it is not designed to handle the increased leverage and strain.
• Insurance: If a non-approved or improperly installed drop plate is involved in an accident, insurance companies may reject the claim.
• Support: It is highly recommended to use a drop plate that has additional supports (trapezium supports) connecting back to the main chassis mounting points to prevent the plate from bending. 

Disclaimer: Regulations can change. It is advised to check with the SABS or a reputable, certified local towbar manufacturer to ensure compliance with the latest SANS standards

Yes these are the specs, but if each individual doen't make work of it to ensure they know what the specs are and check that it is applied to their towing combination you could get these incidents.

I truly wonder how many of all vehicle owners with towbars on the vehicle knows what this specs is and have checked that it it correct.

We just accept that whatever the supplier used to fit the towbar is correct.  I made that mistake once when I had the shocks replaced on my tow vehicle a Ford Saphire 3.0 GLX.  Nearly lost my car caravan and family that day.

I just want to point out to you that the nice guy you talk to at the counter when negotiating the work to be done is not the guy that is actually doing the work.

I also usually ask that I want to stand there while the worker do the work.  If they do not allow that I will take my business somewhere else.  I know OHS rules and what is required so I won't be in the way, but I want to make sure what is done is done correctly.

In May 2016 Mr Johan Gous of the SABS confirmed in writing to me that no towbar and drop plate combination has been tested or certified by the SABS.   The possible combinations are just impossible to test as it has to be done for each and every model of vehicle.   

Basically, if one fits a drop plate to your tow bar, the certification of the tow bar is cancelled.  

Regards

Rather have a tow bar manufactured and fitted that has the correct height.