What Are Some Vehicle Vulnerabilities During 4X4?

[Harison135]

What are the vulnerabilities to your vehicle during a 4x4? from simple and cheap to complex and expensive

I've heard alternators can die, and if the car stops moving in water the water can break your fan. whats common? whats not?

 

[Patriot]

This is a really good question.
From what I have seen:
Tyres - especially on rocks it isn't uncommon to get a flat. Changing a tyre on the side of a mountain on a narrow track can be a lot of fun!
River crossings can be dangerous if you don't have a snorkel (or so I have heard)
There can be horrific damage (and deaths) from snatch recoveries gone wrong.
People getting bogged below the waterline on the beach and having the tide come in.
Low speed roll overs on steep / uneven tracks. These can be a big issue if it rolls on the edge of a steep track.

 

[Harison135]

This is a really good question.
From what I have seen:
Tyres - especially on rocks it isn't uncommon to get a flat. Changing a tyre on the side of a mountain on a narrow track can be a lot of fun!
River crossings can be dangerous if you don't have a snorkel (or so I have heard)
There can be horrific damage (and deaths) from snatch recoveries gone wrong.
People getting bogged below the waterline on the beach and having the tide come in.
Low speed roll overs on steep / uneven tracks. These can be a big issue if it rolls on the edge of a steep track.

my biggest fear is elrctrical issues with water, and broken fans in water. is it true that once the 4x4 has stopped moving turn you car off and hope someone can snatch you out a little bit?

 

[nitrobrent]

Going to depend how hard you go and on what.
IFS vehicles tend to go through cvs and tierods once the going gets tough.
On my solid axle Jeep, in 10 years going hard, been thru probably 5 front axle shafts, 2 sets of front ring and pinions, a front locker, bent the rear drive flange on 3 axle shafts( wobbly wheel).
Bent 6 lower control arms.
1 alternator and 3 starter motors.

 

[Patriot]

my biggest fear is elrctrical issues with water, and broken fans in water. is it true that once the 4x4 has stopped moving turn you car off and hope someone can snatch you out a little bit?

Depends if you have a snorkel and if it is properly fitted. I haven't heard of too many electrical issues, but definitely seen motors getting done, which is sad.

 

[cam04]

What are the vulnerabilities to your vehicle during a 4x4? from simple and cheap to complex and expensive

I've heard alternators can die, and if the car stops moving in water the water can break your fan. whats common? whats not?

Water doesn't kill fans, revs do.

What happens is the radiator and underbody get covered in water and the fan blades torque forwards into the vacuum being created and impact the radiator core. If you aren't revving hard it cannot happen. Select low range 2 or 3 before getting wet then continue at fast walking pace behind the bow wave you create.

I had to engage a forensic engineer once to prove an insurance claim and they explained how it all works (breaks).

Stopping and starting again in water is a non event as far as the fan is concerned - you can bungee the thing to stop it spinning anyway.

Hope this helps allay any fan fears.

Stopping, braking, changing gears underwater are all mechanically bad things and introduce water where you don't want it.

As for turning it off when stuck, if you are in danger of getting a gutful of water in the intake then yes, turn it off. Otherwise i leave it run to keep water from running up the exhaust.

The idea is to keep out of mud and water unless you own a dealership and have a team of mechanics.

 

[John U]

As for turning it off when stuck, if you are in danger of getting a gutful of water in the intake then yes, turn it off. Otherwise i leave it run to keep water from running up the exhaust.

This is what I did on the occasion I got stuck. Mind you I had a snorkel properly fitted. Engine kept running without concern. Started without concern afterwards.

My understanding is while the motor continues to run it creates positive pressure. I'm guessing, as with diffs, if it's switched off and allowed to cool while submerged it'll create negative pressure and could suck water in through seals, gaskets, and those types of things.

Other thing which might be stating the obvious, while it's running, it doesn't need to be started.

 

[FranksnBeans]

This is what I did on the occasion I got stuck. Mind you I had a snorkel properly fitted. Engine kept running without concern. Started without concern afterwards.

My understanding is while the motor continues to run it creates positive pressure. I'm guessing, as with diffs, if it's switched off and allowed to cool while submerged it'll create negative pressure and could suck water in through seals, gaskets, and those types of things.

Other thing which might be stating the obvious, while it's running, it doesn't need to be started.

My understanding with running hot diffs through a cold water crossing is that if water is to be sucked into the diff it will happen at the first instance.

Much like a metalworker quenching a red hot piece of steel in some water, a hot diff will rapidly cool within a few seconds, causing contraction and hence the negative pressure internally. So once in the river and idling away due to being stuck, there should be no chance of water getting into the diffs unless your seals are already buggered.

As said above I cross rivers at a fast-walking pace, creating a bow wave which I follow. I avoid changing gears at all costs, I just drive through in 2nd-low at slightly above idle. I've had water over the bonnet more than a few times and never had an issue (so far).

 

[Albynsw]

Provided your vehicle is in good mechanical order and you have the appropriate modifications for the conditions you are in the most vulnerable part is the driver

It is best to drive with mechanical sympathetically and to the conditions plus wheel placement is important to minimise wheel/ tyre damage
Often a lot of damage is self inflicted

 

[Colly18]

Depends on where you are doing your 4WD'ing I guess!? Steering components, lower radiator tanks, and engine sumps looked pretty vulnerable in my past couple 4X4's. It's easy enough to make a simple mistake and drop onto an unforgiving obstacle (I know from experience). So for me a decent front end-under engine bash plate is good insurance.

 

[cam04]

The only way to create negative pressure in the diffs is to leave the old breather caps either in place or on the end of the extensions. If you have extensions which breathe both ways you’re good.

 

[typhoeus]

Some people drape a tarp or similar over the front to Deflect water and minimise water in the engine bay. Starting an engine half submerged Is to be avoided at all costs, and without a snorkel, water crossings must be very carefully considered.

 

[2luxes]

I will always remember my first water crossing. Ten of us put a tarpaulin under a Holden ute then carried it into water ten feet deep and paddled it down to the other end of the pool.

That was at the Army vehicle recovery school at Bandiana Victoria. We were not doing it for fun, it was one of the ways they got vehicles across rivers.

Another thing that causes plenty of damage to cars is desert driving on unsealed roads and tracks. The main problem there is incorrect loading and excessive weight, particularly when combined with excessive speed.

The damage that occurs far too often out there is bent chassis, broken front or rear axle housings, broken axles, sheered wheel studs, buckled wheels or the centres torn out of wheels. If that is not enough, there is overheated engines or auto transmissions.

There are plenty of photos of this type of damage on the net.

A point to keep in mind in those conditions is the forces going up into the car and its suspension when driving over holes or corrugations in roads or holes at the edge of cattle grids increase by the square of the car's speed. That is what causes most of the damage.

 

[mikehzz]

I will always remember my first water crossing. Ten of us put a tarpaulin under a Holden ute then carried it into water ten feet deep and paddled it down to the other end of the pool.

That was at the Army vehicle recovery school at Bandiana Victoria. We were not doing it for fun, it was one of the ways they got vehicles across rivers.

Another thing that causes plenty of damage to cars is desert driving on unsealed roads and tracks. The main problem there is incorrect loading and excessive weight, particularly when combined with excessive speed.

The damage that occurs far too often out there is bent chassis, broken front or rear axle housings, broken axles, sheered wheel studs, buckled wheels or the centres torn out of wheels. If that is not enough, there is overheated engines or auto transmissions.

There are plenty of photos of this type of damage on the net.

A point to keep in mind in those conditions is the forces going up into the car and its suspension when driving over holes or corrugations in roads or holes at the edge of cattle grids increase by the square of the car's speed. That is what causes most of the damage.

I've thought it over and I agree, speed causes the most damage to cars when 4wding. Many people toughen their cars up to be able to take the hits, and then they proceed to hit the crap out of them, driving with little or no mechanical sympathy. Overall, tyres are the easiest and most common point of failure in my experience. I wouldn't turn the car off if I was stuck in deep water, but I would be kicking my own arse for being there in the first place. The thrill of conquering obstacles soon gives way to the pain of paying for the inevitable repairs. It's cheaper to watch other people break their cars.

 

[John U]

Theres a longer version of this clip. It looks like they'll run all day underwater if you don't stop them.

 

[mikehzz]

It's more fun watching this than doing it

 

[typhoeus]

Theres a longer version of this clip. It looks like they'll run all day underwater if you don't stop them.

Prepping a vehicle to do that is a major exercise, costly and you have to be meticulous. And it's usually a one off attempt, because corrosion inevitably affects critical parts.

 

[ULost2]

If you want to be stupid enough you bugga anything even if it takes sometime to prove you buggered it . Like my Suzuki! Have spent $10K fixing a previous owner **** driving fun!!
Couple of one-liners.
Then they wonder why 4x4 fun becomes $$x$$ tears.
More fun 4x4 fun becomes $$x$$ tears.
That was fun --- now how do I get to work to pay for that fun .
And a new one-liner for my "book" --- make that 2 now :lol:
Everything has vulnerabilities but it often takes an idiot to find it.
"Mates" and peer pressure will help really sensible people find the slightest vulnerability of a 4x4.