Re:Jimny Gen 4 Diff Breathers?

Fitted the Des-Sol breather kit today.

Couple of tips:

A ramp and “diff cap removal tool” will make the fitting process so much easier. Without these it would have defeated me.

If the kit any good? Too early to tell but first impression is one of delight. Addresses the only real flaw in the JB74 - wading depth.

Let’s see if the connections hold up.

Diff. breathers are only part of the problem. The rear wheel bearings have a very simple and consequently crude sealing system that is designed primarily to keep grease in and maybe the dirt out. They are not designed to keep water out so if you wade deeper than the bearing you will inevitably allow water into the bearing and that will quickly destroy it. In the past I have modified the shaft and the housing to add a standard 2RS ( 2rubber seals ) oil seal and that solved the problem. The front axle is a totally different design and has totally different problems. Water ingress past the large seal on the steering knuckle is inevitable because it is not designed to keep water out and is the main reason why the water that gets in, if you deep wade, will quickly destroy the king pin bearings. The seals on my old Land-Cruiser did a better job of keeping water out but the workshop manual stipulates that the knuckle should be filled to 3/4 capacity with grease.
From memory, lambert has said that he doesn't wade deeper than the depth of a tyre ie approx. 5".
Fitting diff. breathers will help to protect your diffs. but to protect the lot you need further work.

Roger

RumbleAndSway wrote:

Fitted the Des-Sol breather kit today.

Couple of tips:

A ramp and “diff cap removal tool” will make the fitting process so much easier. Without these it would have defeated me.

If the kit any good? Too early to tell but first impression is one of delight. Addresses the only real flaw in the JB74 - wading depth.

Let’s see if the connections hold up.

If you are regularly going to be in deep water then you have to accept significant shortening of the service life of every component that you partially submerged. I personally resist getting the bottom of my wheel rims under water others draw their lines somewhat higher. And that's before you decide on how dirty the water you are prepared to play in is. Clean flowing mountain runoff is very different to silted muddy holes on a pay to play site. The worse the environment you use it in the more you need to look after it.

My Gen 4 came to me with a snorkel fitted and I haven’t checked, but I suspect the breathers aren’t extended, which kind of defeats the point of a snorkel.

So far, like Lambert I haven’t been over the wheel rims, but with BigJimny coming up and I intend to join a local club I can see I might be going through a bigger puddle from time to time.

So should I fit a breather kit?
Which one to go for (in the UK)?
Are there any downsides?

Robin

I personally think the only down side is that simple wading modifications give a sense of "invincibility" that erodes the caution that exists with a standard vehicle. As Roger pointed out plenty of remaining items that will suffer underwater, but at least the differentials will (may) be ok. Don't forget the gearbox / transfer box breathers, clutch, engine bay electrical sensors / smart alternator, headlamps etc etc, the list is endless if you go deep enough for a dip.
Stay out of deep water unless you have built a 100% off road use vehicle, it will damage things.

Lots of good/wise advice, thank you.

Winter 2023/24 delivered a number of weather events and regular flooding on my bi-weekly Guildford to Brighton commute. Nothing crazy but 10cm-20+cm of standing water in places.

A journey I usually make in other cars but on these occasions I use the Jimny.

Only concern was the vulnerability of the standard diff and TC breather caps.

Snorkel [OTT] and breather upgrades offer additional peace of mind.

I will not be forging rivers.

Thanks again.