jimny will not engage 4wd

[Rubber-Lubber]

was 4wding yesterday and turns out only had 2wd. Front drive shaft turns 4 low gearing engages no noises from diff. Am thinking it is vacuum operated hubs. Can anyone help with this?

[mugginsmoo]

it's the hubs, throw them away and get som manual hubs.

there are several ways to fit manual hubs

1 get some sierra hubs and remove the circlip off the end of the CV, then bolt 'em up ( as i have done)

2 get a 5mm spacer machined up and bolt on a set of sierra hubs

3 get a set of hub for a jimny from japan ($$$$$)

[Rubber-Lubber]

thanks mugginsmoo will look into it might just throw the whole thing hahaha

[Offroad-Events]

In the meantime check the vac hoses for leaks. Might turn out that the hose popped open somewhere between the axle and the valve on the drivers side inner fender. And yes, get some manual hubs !

[gman79au]

It has been common on the g13bb engine the vacum hose going from the manifold to the one way valve on the hub locking system which can be found under the battery splits at the manifold end anyway does the 4wd light flash?

[brianstevens]

Hi everyone.......ME TOO!!!!

I was wheeling this weekend and once I got stuck in the mud I realised my front hubs had not engaged (at least thats my diagnosis).

I've been wanting to install manual hubs before this happened as I hear it's common, but alas I'm too late.

My 4WD light is on as usual so I'm sure exactly where the problem is. If there was a vacuum leak would the 4WD light flash??

[gman79au]

there is a vacum sensing switch on the locking vacum circuit of the hub locking system if vacum is sent to the hubs to lock them and it's escaping some where the 4wd light will flash, if there is a blockage so the vacum is still in the system but no reaching the hubs it won't flash, you can hear the hubs lock in, I recently rebuilt my front hub system and it works great now

[brianstevens]

I've done the hub conversion an all is well. The problem now is the 4wd light is flashing because the vac hubs have been removed. If I clamp the vac hose under the battery it all works fine but I'm looking for a proper solution. How do I bypass the vac sensor??

[gman79au]

the 2 pipes which travel down the firewall to the hubs, if you join them so the vacum can travel in a loop from one solenoid to the other it will fix the problem. otherwise under the battery with the locking solenoids there is a grey device with 1 vacum line going to it, 2 wires in a loom and a small vented foam filter hanging off it. this is a vacum switch and it tells the 4WD control module there is vacum in the locking system (but only for 10 sec). If you get the main vacum supply from the manifold and plug on to the end of this sensor, it should also fool the module and the 4wd light will stay on. first option is the easiest.