4WD Light Flashing - Safe to drive??

Hi All,

I'm having some troubles with this JB13 Jimny of mine - it's currently up on the hoist while I get some work done but I have a couple of questions that I'm keen to get answers for.

They seem pretty fundamental to me and I can't seem to find a definitive answer for (or as definitive as possible).

I'm going to have the front hubs rebuilt with the kit from the BJ website (not sure what the difference between SKF / KOYO bearings are tbh?) after the 4WD light started flashing last weekend when I was trying to lock the hubs in, didn't hear the normal click sound. 

The 4WD green flashing light just kept on flashing so I drove it home - is the thing safe to drive like this? Is it possible that it could attempt to lock in the hubs 'at speed' and cause damage?  

If the above is the case and the system is trying to engage the hubs then it seems somewhat pointless having the mechanic do the hubs work until the system for locking in the hubs is sorted out or it could lead to (in my mind) some sort of coggy explosion?

The thing does wobble and I've noticed that there's some oil leaking out from the knackered hub setup (blocked one of the vac hoses and causing the flashing) on the nearside.

I've opted to do both sides while we're on with the rebuild kit. 

Given the apparent flakiness of this button based system if I decide that ditching the vacuum setup for freewheeling hubs is best then can someone explain how the whole getting it in and out of 4wd / 4low will work? I'm thinking that:
2wd button = disengage hubs 
4wd button = engage hubs / take it out of 4Low
4low button = works as I would normally expect when it's in 4wd mode? 

Thanks for any pointers with this. 


 

Flashing green means that the 4x4 has not properly engaged which is more than likely, but not exclusively, the vacuum pipes to the hubs are leaking. As you said manual hubs are one alternative and come with the advantage of being able to use low range on a high grip surface if you don't twist the hubs in which is useful if you have to manoeuvre a trailer in a yard for example. There is also a down side that you have to get out of the car the first and last time you need 4x4 though you can switch between 4x2 and 4x4 just using the buttons if you are doing a mixed day of back roads and loose green lanes or fields as an example. Some people do leave the hubs twisted in permanently but it does increase wear and fuel consumption marginally. The other option is to replace the vacuum pipes and save the cost of manual hubs and if you use silicone rubber lines you should be free from having to redo the same any time soon unlike the Suzuki steel pipe that seems to rust for fun.

When you say you're having the front "hubs" rebuilt, which bit are you referring to? Where is the oil leaking from? If it's the large swivel seal this is completely separate to the operation of the vacuum hubs. If it's the wheel bearings then the seal behind the wheel bearing is critical to vacuum hub operation, and a failed wheel bearing is a likely cause of a flashing 4wd light.

Details of how and when to use the 4wd system are in your handbook and a brief summary is written on the sun visor. The hubs engaging at speed isn't a problem, but driving continuously with it in 4wd is. As you have buttons for 4wd I believe, after detecting a vacuum fault, the transfer case will revert to 2wd. To get 4wd 2 things need to happen- the hubs must be engaged and the transfer case must engage drive to front axle. So hubs alone can not put the car in 4wd.

Thanks Lambert - I guess what I'm trying to understand is if you have freewheeling hubs then I can expect to use the 4wd / 4wd Low buttons 'as normal' once the hubs are locked in?

Thanks Busta

I'm doing the lot since the kits are only about £100 I figure replace all the parts that they come with while all the hubs are stripped down and apart. The Oil seems to be coming from the swivel seal but I read online that oil can contaminate the vacuum pipes when the area around there starts to get on in life - considering I've got a leak (on the nearside) and failure to lock the hubs in I figured 'do the lot' as it were...

With regards to the hubs engaging at speed - I was always under the impression that you had to be stopped to lock the hubs in with the button and I was worried that they could somehow lock in while in motion and cause greater damage?

So you are replacing the wheel bearings as well as the kingpin bearings and swivel seals? There is no path by which oil from the swivels can find it's way into the vacuum system so that is very unlikely to be the source of your issue.
4wd can be engaged at up to 60mph as per the instructions on the sun visor and in the handbook.

Just fixed my blinking Jimny.
My blink stopped if I turned the car off and back on again.
My 4wd issue was the actuator on the push button case had too little oil to function properly. I could most of the times hear my clicking hubs ok and knew of a leak in the transfer case.
Changed an axle seal and the oil in the case, and after a few minutes of switching and rolling it worked fine again.

Hi Busta, you're a braver man than I if you chuck it into 4wd doing 60mph... I've been going off the first part of the do's and dont's on the BJ website:

www.bigjimny.com/mediawiki/index.php/DO%...%27T%27s_with_Jimnys

This sounds quite possible with what I've seen under mine, thanks for posting this I will pass the information along.

Not sure if I would push the buttons doing 60mph on gravel, snow or ice either
Most likely would keep my eyes on the road and hands on the wheel..

But 60kmh is no problem engaging or disengaging the 4wd.
No practical need for the 4wd above 60kmt in my opinion.

You shouldn't be afraid of selecting 4wd at speed. Whilst all my Jimnys have had manual transfer cases, all have effortlessly shifted in and out of 4wd while moving at any speed. The only time you will ever cause damage by selecting 4wd is when the front and rear axles are turning at different speeds, in which case the hubs will engage with a bang. However that is much more likely to happen at low speeds than high. I do agree with Yakuza that in such a low powered car you never need to use 4wd at high speeds, but that doesn't mean you can't.
The wiki refers to a bang when returning from 4wd to 2wd. This is a different issue, and is caused by the release of tension in the drivetrain. As such the bang itself isn't going to cause any problems. However, whenever this occurs it is a reminder that you were using 4wd when you shouldn't have done, putting unnecessary stress on the drivetrain that, thankfully, has now been released. So I definitely don't agree with the idea of reversing every time you wish to switch back to 2wd. Better to do it while driving normally and if you do hear a bang take it as a lesson that you already did something wrong.

All true Busta.

I also had problems with the 4wd this winter as it would not get in or out of 4x4 when it was more than minus 5 degrees. This could have been the actuator as well and too low oil level.
Or as my first though, coondensation in the vacuum system turning to ice.