Grand Vitara 4WD selection issues

[andrew_wale]

G'day.

Last weekend the GV had issues with engaging 4WD.
Even though I had moved the little stick in the low range, the thing would not engage 4WD.

At least it was going down the hill..

The GV is semmi electronic i.e the stick does change to the low range gears but it also engages a switch which in turn enabled a small air pump.
The pump then put 9PSI onto a diaphragm in the front DIFF to engaged 4WD (when the the front manual hubs are locked).
When I got back to Licola and unlocked/locked the manual hubs, 4WD decided to work.

I find it hard to believe that it was just the hubs playing up as I can select 4WD even if the hubs are free.
However, I must admit, I do need to take the hubs apart and clean them.

The is the first time 4WD has not engaged. So I am wondering who I should talk to about this.

I do not want to get stuck on a track without 4WD..
Any Suggestions.

[christover1]

I knows zero about the inner werks of a GV.
But manual hubs can stick open or locked. Usually rust or mud or too much grease.
When mine stick, usually a clean and a quick spray of wd40 type stuff is enough.

christover

[andrew_wale]

Well. I spot to Matt at Total Traction.

The cause is probably the air pump that engages the front axles and the diff.
What sometimes happens is the the oil in the pump goes hard when it is very cold and therefore does not pump enough air it to the diaphragm and therefore the axle lock clutch will not engage.

Stupid setup.. All so the driver does not have to get out of the car to engage 4wd.
Other makes have different setups to deal with this...

A front air locker will remove the need for the air pump setup. But an expensive option. At least I know it will be in 4wd though.

[gwagensteve]

I could be wrong Andrew, but I'm pretty sure an airlocker won't make any difference. Deleting the actuator and "broken shaft" system suzuki use to disengage front drive without using free wheeling hubs is a separate issue to what diff centre you choose to use.

I'm sure Matt can sort out the parts required, but on the face of it, I'd say a 2.0 vitara axle set and steel housing (if you don't already have one) would be what you'd need.

PS ALL chevrolet pickups between 1988 and about 1998 used a similar system but use a heating element in a can on the axle housing that heats fluid and then pushes the actuator in. It doesn't work at all in the snow.

Steve.

[andrew_wale]

The reason why the air locker will remove the little air pump arangement in the GV is that it removes the need for the outer Diff Centre casing.
The outer Diff Centre casing holds the air actuated Axle clutch..
From 1998 - 2005 the Suzuki Grand Vitara's are the only makes of 4wd's that have this setup.

With the Air Locker installed, it basically turns the GV diff (in my case a Vitara 4.6:1) diff into a standard open/locked diff with out the Axle clutch thingy that can go wrong etc.
The only issue will be re-wireing the 4WD light on the dash board as this is controlled by the air pump electrics.
With the air pump actuator, the 4WD light on the dash will only come one when the electrics have detected the axle clutch is engaged.

The 4wd light I suppose is not that important. At least I will know it it is 4wd or not.

The Air Locker will also add strength to the diff centre (Ask Matt how this works).

[gwagensteve]

I'm well aware of the added strength of the airlocker Andrew, but as I originally posted, the solution doesn't require an air locker - any full case locker, or vitara front centre would also do the job.

If you're looking for a reason to fit a airlocker though, it's a good one.

PS the 4WD light isn't important if you have manual hubs - once you're on road and the hubs are unlocked no damage could be done if you accidentally shifted it into 4WD.

My G wagen and Sierra don't have 4WD indicator lights.

Steve.

[cj!]

Andrew, as Steve has mentioned an airlocker is not necessary to resolve this but it is a good excuse to fit one. Any front diff centre from a 2.0 manual Vit, either 4 cyl or V6 will bolt straight in and have the 4.625 R&P and 26 spline sidegears although you would really want to have them swapped into your steel housing. Just check the length of the LHS inner axle shaft as there are two different lengths and I can't remeber offhand which one you need. The other option is just to pick up any Vit centre and have the required parts swapped into yours. That said, there will be costs to have this done and if you don't mind paying the extra $$$ then having an airlocker fitted would be a nice thing if you anticipate keeping the GV for sometime. Having a 4wd light or not as the case maybe is not really an issue as you should know if you have engaged 4wd anyway.

[christover1]

I am assuming the 4wd light isn't connected to the ecu, or have any imput to engine management ??
I doubt it tho.

[robsjimny]

The light would be the easier and the cheapest to get working. Bypass the module. It should have a input from the level or transfer. The output to the dash light and pump thingy. I would be more worrried about getting the front wheels to drive.

Rob

[gwagensteve]

I am assuming the 4wd light isn't connected to the ecu, or have any imput to engine management ??
I doubt it tho.

Not on a GV.

Some late model stuff from Land Rover does though - they run a different engine map in low range that provides "softer" throttle response - kinda like having a longer throw throttle pedal.

Steve.