What’s the weakest link in your 4WD recovery?
What if I told you that a large majority of 4WD recoveries done locally are not safe? Would you believe me? When you do a recovery in your 4WD, it’s good practice to take a second before going through with it to consider what the weakest link is. This way, you know what is most likely to go wrong, and you can act accordingly.
The forces on 4WD’s involved in a recovery can be astronomical, and things regularly go wrong. People get serious hurt, and killed when things go wrong in 4WD recoveries; make sure you are happy things are being done safely before you go ahead with it! I’d highly recommend you have a read of the 20 things you should never do in a 4WD recovery.
Unless you have installed aftermarket recovery points, there’s a good chance they will not be rated. A lot of ‘recovery points’ used by people are actually tie down points, used for transporting the vehicle. Make sure you are running Rated recovery points; these are seriously dangerous if something breaks!
So lets say you’ve got some nice new recovery points on your 4WD. What are they rated at? What is your snatch strap or winch rated to? In a large majority of cases, you will find the weakest point in your 4WD recovery is actually the recovery points themselves. Take the standard hooks for example, rated at 10,000lb or 4535kg.
If you attach a normal snatch strap 7500, 9000 or 11000kg to the recovery point, is that safe? No, its not, and yet majority of 4WD recoveries are done in exactly this manner. Your rated recovery points are often the weakest link, and you need to consider that.
You wouldn’t pull a 3 tonne Land Cruiser out with a 4.5 tonne snatch strap, so should you really be using a single 4500kg recovery hook?
What condition is your chassis and captive nuts?
Recovery points are bolted to your chassis, and are often held in place via captive nuts. These are nuts that have been welded to the chassis from the factory. However, your chassis takes a beating, and will often sit with mud and sand inside for years on end, causing rust. If you haven’t had your recovery points off, it’s a very important exercise.
Remove the recovery points, and check the bolts. When I pulled the old recovery points off my 80 series, a good third of the bolt shank had rusted away. Even if you have a modern vehicle, it pays for piece of mind just to pull the recovery points off and check the bolts and captive nuts.
Check the captive nuts; if they are rusty, or the thread is damaged, you need to do something about it. There’s no point having a nice recovery point if its attached to something that’s going to allow it to snap off! The more area your recovery points are spread across the better. If you can bolt them on with 3 captive nuts, its a lot better than 2!
Are your bolts tight enough?
Your recovery point is held in place by a number of bolts (which should be grade 8.8). The strength that they offer though, is a direct reflection of how tight they were done up. One person’s ‘tight’ is very different to another! There are plenty of tables online which will tell you the correct torque settings required for your bolt (check the pitch). Make sure you use decent washers to spread the load too. Do not over tighten them either, or you will strip the threads and be in an even worse situation!
Next time you do, or see a 4WD recovery, take a second to think about what is likely to go wrong, and do what you can to prevent it!
You should not be using a Tow ball in a 4WD recovery. Period. Tow balls are not designed for rapid stress that snatch straps and winching can put on them, and will shear off. I’ve seen plenty of photos of tow balls that have gone through tyres, front and back windows and even panels. They are not to be reckoned with; take them off when 4WDing and leave them in your vehicle, in a safe and secure place. If you need to recover from the rear of a 4WD, you should be using a Rear recovery hitch, or rated rear points.
You can read more at Tow balls in 4WD Recoveries can kill you.
The way that a snatch strap works is essentially the same as an elastic band. As you pull another vehicle out, the strap will stretch in length by about 20%. When it reaches this point, all of the stress in the recovery is applied to both vehicles, and this is when your strap is most likely to break. Snatch straps are very useful for 4WD recoveries, but they are also by far and away the most dangerous piece of recovery gear.
When you use a snatch strap, make sure you spend a few minutes behind a shovel, clearing what ever it is out the way of the tyres on the stuck 4WD. The less stress you apply in a 4WD recovery, the less likely you are to have something break.
Use the correct weight rated snatch straps (the breaking point should be 2 – 3 times the weight of your loaded vehicle). If you are recovering a vehicle that is towing something, make sure you factor this in.
When a snatch strap breaks, it will flick away at a rapid rate. It’s a good idea to use a dampener on all snatch strap recoveries, and in every 4WD recovery people should be standing at least 1.5 times the length of the strap away from the vehicles.
For more information, have a read of this; when should you use a snatch strap?
Most 4WD recoveries are done using 3250kg or 4750kg bow shackles. Make sure they are stamped with a WLL! Personally, I think the 3250kg ones aren’t heavy duty enough, and I won’t use them. The 4750kg shackles are a much better option. Although they are actually rated for less than your snatch straps and winch, they have a safety factor of around 5 – 7 times the weight. These are not likely to break, but again, match your recovery gear together so its all rated correctly.
Use an equaliser strap
If your recovery points are only rated to 4500kg, you should be using an equaliser strap over two recovery points. This gives you 9000kg to play with, which is much safer. It also helps to spread the load over your whole chassis, so you don’t end up with a vehicle that is longer on one side than the other!
My recovery points are rated at more than that
Good. Not many are, but you will occasionally get recovery points that are rated to 10,000kg. Still, should you really be applying that much force to one side of your chassis? An equaliser strap is good insurance.
Have you reduced any missiles?
Shackles play a very important role in 4WD recoveries. Still, if I can avoid using them in a 4WD recovery, I will. Not because I think they are going to break, but because of their weight, and what happens if something attached to that shackle breaks.
It’s good practice to remove anything from a recovery that isn’t absolutely necessary. If you need to join straps, do it the correct way (without a shackle). If you need to attach a winch to a tree trunk protector, use the winch hook, without a second shackle.
If you are attaching a winch or strap to your recovery point, don’t use a shackle unless you absolutely have to. I don’t mean you should choke a strap around a recovery point to avoid using a shackle, but just reduce anything that could fly off and kill someone.
Is your equipment in good condition?
My first snatch strap was a pretty light weight one (maybe 5000kg), which was fine for my Hilux. However, it’s been used that many times now, and I’ve decided to get rid of it. You can see obvious signs of wear and tear, and it doesn’t suit my 80 series Land Cruiser any more. Before you use your recovery gear, just run your hands and eyes over everything to make sure it is still safe.
Little nicks, tears or frayed sections are bad news, and mean you need to be getting new recovery gear. There are a few pieces of recovery gear that shouldn’t wear, and you can use them for life. However, things like snatch straps, tree trunk protectors, winch cables etc are all going to wear over time, and need to be replaced before something goes wrong.
Is there a better option for the recovery?
Unless you are bogged chassis deep in a stinky salt lake, you can often get a 4WD moving again without the need of a snatch strap or winch. If you can, this is the best option. Things like deflating your tyres to a better pressure, using Maxtrax or spending 5 minutes with a shovel are much quicker and safer than using another vehicle to recover yours.
So, what’s likely to break then?
The big question – What’s the most weakest link in your 4WD recovery? I hope this post makes you stop for a second before performing a 4WD recovery, just to consider what could go wrong, and what you should be doing to avoid it. Have you had any nasty accidents when recovering a 4WD? What else have you learned?
All good mate; look after yourself!
Nope, I was wrong. I’m still the idiot who can’t read numbers; What I said doesn’t even make sense… Oh well. Disregard my last comment. But thanks for the response. Also, thanks for the information. I’m new to this and doing this on a vehicle that really shouldn’t be so trying to extra cautious understanding the numbers and forces.
Haha! Sorry mate. We haven’t typically had a huge number of American visitors to this site, so welcome.
NGL, it took me way to long to realize that although the website is *.com its locale formatting is different. Was going crazy trying to wrap my head around 4,000kg rated points… ‘,’ instead of ‘.’ derp. Chalk another one up to another stupid American playing with American formatting rules…
The elasticity might be a thing, but I’ve never experienced it first hand. The fact that the hook is welded to the chassis rings alarm bells to me, unless its a factory fitted item (which I reckon it wouldn’t be).
I think the tow bar will be bolted on; you’ll probably find that the bolts undo and feed into captive nuts. Either way, I would get someone qualified to verify its strong enough.
All the best
Thanks for you reply.
That’s where I heard about the elasticity (from 6:30): https://www.youtube.com/watch?v=KcUDgmSMhWk
I just had a look to my car and the front hook is welded to the chassis but I couldn’t find any stamp.
The situation of the tow bar is a bit complicated to describe but I give it a try.
At the rear is a pipe (which is part of the chassis and where cables for the lights are running through) and on the pipe is kind of a metal block welded. The tow bar and the metal block have four holes where screws are screwed in to connect the tow bar with the car. The screws look like M12. Not 100% sure because I can’t measure the diameter but the head is 19mm wide.
Soft shackles are a good option, as you mention. I think the snatch strap elasticity is a myth; I’ve never experienced that in real life, and never had any issues with elasticity or breaking one.
These days snatch straps are my least preferred method of recovery anyway, unless its an easy recovery.
Are you saying your tow bar is attached with screws, and not bolts? What diameter are they? I would take it somewhere to be assessed, as generally the rear tow bar is the safest place to recover off, providing its attached properly.
If your Pajero has a monocoque chassis you may find getting recovery points is a bit more of a challenge.
Make sure the hook on the front is stamped with a WLL and the bolts are in good condition (remove one and inspect it), along with the chassis that it goes into.
All the best
I probably have to add 2 things.
1. You write about bow shackles and that they can became really dangerous (totally agree on that). But what about soft shackles? They can be a good option if you don’t attach them to sharp edges.
2. I don’t know if it’s true, but I heard that you shouldn’t use a snatch strap for more than 3 (or max 4) consecutive recoveries because they will loose elasticity. After you should let the strap recover for 48 hours and change the strap if you’re still not out.
Atm I’m preparing for my big road trip. On my 95 Pajero I only have a hook on the front (as shown below in the picture) and on the rear I have a tow bar, but it’s attached with screws. So I’m not sure if I can use it for recoveries. I was already looking forrecovery points online but can’t find any for my car. Any suggestions where to look for?
You aren’t wrong!
That would be fantastic. Please flick it through to admin at 4wdingaustralia.com
As you can deduce from the above, I have a bit of an obsession about safe 4WD recovery. The underlying issue is that unlike most things in our lives, there appear to be no regulations governing the recovery gear industry. So whilst industries (such as hoisting with cranes for example) using trained personnel are heavily regulated, 4WD recovery undertaken by members of the public, is not. Essentially each manufacturer is free to determine their own safety criteria and foist their products onto an unsuspecting end user. For some reason the consumer laws regarding ” fit for purpose” do not seem to apply to the 4WD recovery gear industry. The outcome, a never ending trail of accidental deaths during recovery and no-one held accountable.
I regard this as a gross dereliction of duty by the relevant authorities, whose sole “raison d’etre” is to protect the public.
The main problem for the purchaser of recovery gear is unambiguously understanding the safe capacity of the gear they have just bought. I am a structural engineer, I do this for a living and I sometimes struggle to fully understand what the manufacturer is claiming for their product.
I drive a (heavily laden) Troopy, so when I get bogged I usually do a pretty good job of it. Hence I am particularly interested in what is involved to “debog” it.
I have written a monograph “A Guide to the Correct Sizing of 4WD Recovery Gear” which I could forward, if you thought it may be of interest to your readers. It covers:
The forces required to debog your 4WD.
The capacities of the various items of 4WD recovery gear.
The appropriate solutions for 10 recovery scenarios, from snatching to winching out backwards.
A summary of the appropriate recovery gear sizes based on the vehicle’s GVM.
You certainly raise some interesting points again, and a couple I hadn’t thought about before. There is a real need to be careful in a 4WD recovery, as there’s been far too many accidents.
All the best
Further to the above, the weakest link in your 4WD is not the tow hook, pitiful though it may be, but the rear tow bar.
The typical Heavy Duty (Class 4) 3,500kg ATM tow bar is designed in accordance with AS 4177 (Part 1) which covers the design of tow bars for towing caravans and trailers up 3,500kg ATM, on public gazetted rods only and are labelled accordingly.
They are NOT rated for off road driving or vehicle recovery. This is because the forces involved in towing a 3,500kg trailer on a public road are a fraction of those incurred applying a recovery load of 3,500kg to the tow bar.
Regardless of the above, the reality is these tow bars are routinely used for recovery by their owners, no doubt the majority blissfully unaware of the potential consequences of what they are doing.
This already dire situation is further exacerbated by then using a hitch receiver with a WLL = 5,000kg. This is an interesting definition of “safe” by the manufacturers of these devices: Our hitch receiver has a safe load capacity of 5,000kg when attached to a tow bar with no rated recovery capacity. . . .
The safest answer is to have rated rear recovery points or use a “recovery” tow bar. Hayman Reese make two: the X bar and the Mine Spec. These have two integrated rated recovery points in addition to the central tow ball mount.
I think we would all agree that the 4WD recovery field is a total dog’s breakfast! Safe loads mixed up with breaking loads and everything in between. My favourite is the soft shackle industry which gives “Rated MBS” capacities for their products. Rated is a legal term. It means safe. So what they are essentially saying is that it is safe to use their product up to its breaking load, but if you do, it will break. You would swear that this stuff is written by their marketing departments to make their products appear stronger. No engineer would write this nonsense.
Interesting, and valid comments. These days the 4500kg tow hooks seem to be less common, with people moving to proper, rated plates and using shackles inside of them. Most of the plates are rated for much more, and have significantly more bolts in place to hold them there.
Ideally you don’t really want to be anywhere near the 4.5 tonnes applied to one side of the vehicle anyway. It’s always better to take a cautious approach.
All the best
Very sensible advice, but with the following comments if I may.
The 4,500kg capacity quoted for a tow hook is a WLL, ie a safe allowable load.
The 7,500kg etc quoted for the snatch straps are MBS, ie minimum breaking loads.
If you abide by the manufacturer’s advice to use a snatch strap with an MBS = 3 times the vehicle’s GVM, this will reduce the actual load on the tow hook back to something approaching its safe capacity and hence OK.
On a separate subject, I have a much bigger issue with the 4,500kg safe capacity quoted by the manufacturers for their tow hooks. Their designs are based on the American 10,000lb tow hook (4,536kg) which are supplied in America with two 1/2″ (=12.7mm) SAE Grade 8 (=10.9) bolts, with an allowable shear capacity of 2 x 5,000lb = 10,000lb ie OK.
In Australia, these same tow hooks are supplied with 2M12
8.8 bolts, which have an allowable shear capacity of 2 x 1,560kg = 3,120kg < 4,500kg x 70% ie NOT OK.
Upgrading to 2M12 10.9 bolts will increase the allowable shear capacity to 2 x 2,015kg = 4,030kg < 4,500kg x 90% ie still not OK but a whole lot better.
Furthermore the above capacities are based on loading the tow hook straight ahead. For loading in any other orientation, these already inadequate capacities are reduced even further.
Sounds amazing over there; a whole different world!
All the best
Very good thoughts. I always think the same way, but of course we are as humans lazy by nature. I do think that I know quite a bit about 4wd and recovering but are always learning things that I haven’t heard about or thought about. I live in Sweden and off road here is all about narrow paths between big trees, mud/boggy stuff, roots and boulders. Usually it’s impossible to dig because of the roots. Maxtrax or equivalent can’t go in under your vehicle, cause you can’t dig and the rots and/or rocks/boulders them self. It often leaves us with the winch or snatch strap possibly being the only option. Generally the situation doesn’t allow a exhaust jack to be fitted under the vehicle. There do are the option of lifting the vehicle in the front or the rear with a farmjack, but I do consider that being equally dangerous.