[Scott_1988]

Hi everyone,

How do I tell if the vacuum hubs are engaging/disengaging?
Can you physically see them moving when you go from 2wd to 4wd and back?

When I engage 4wd sitting in my driveway the light comes on green and stays steady, no flashing, which is good. But when driving in 2wd on the road there is a bit of a whine from the front and someone else mentioned that it might be the hubs not disengaging properly so the front diff could be causing the noise if it isn't disengaged. I was wondering how do I check if that is the case. And if anyone wants to know, I haven't driven on the road in 4wd

My Jimny is a 1999 with the shift lever, not the buttons on the centre dash.

Thanks, Scott

[AckerDackerly]

I am a 'feriner from a backwards country that don't have Jimnys...

That said...

If the pneumatic system is a similar design to the IFS vits, you will not be able to see external moving parts in action.


I would assume that, if the front axle is stuck in the 4X4 mode, try jacking one of the front wheels off the ground.

When this is done, you should be able to turn the raised wheel whilst watching the front propshaft. If it turns when the lifted wheel is turned (with the transfer case in 2wd) even when someone is holding it firmly to keep it from turning, the locking pneumatic mechanism is stuck in the engaged mode.

I would think that is probably not the case as these types of systems are designed to not engage unless the pneumatic system is in operation...

I hope that this helps!

[Scott_1988]

Thanks Ack, that makes sense. Will give it a try.

[Scott_1988]

I suppose I could d the reverse as well to see if they are engaging in 4WD mode?

[Scott_1988]

Hubs are working as expected. I am pretty surprised because it doesn't look like the vacumm tubes have ever been replaced since 1999.

Anyway, need to look somewhere else for the whining sound, probably the trans, it is a bit clunky.