Spinning backwheels in 4-WD

Hello everyone!
I used my "new" Jimny DDIS to pull out the boat from sea before winter this weekend. It worked but was not easy on a muddy  shore. We noticed the backwheel spinning from time to time but not frontwheels. Is that to expect to happen in 4-whell drive (not L) with the Jimny gear construction? Just wont to rule out there is fault in transmisson.
Thansk for listening and take care
Ulltand
 

You have more weight over the front wheels, so they might be less likely to spin, but in general no, you wouldn’t expect only the back to let go and not the front. It might also depend on the surface, if the front wheels were on the slip way and the back on sand?

Do you know if the front wheels were been driven? One way to tell is put the car in 4wd, jack a front wheel up and see if it is locked or spins by hand. Then shift to 2wd and the front should spin by hand.

In 4wd a standard Jimny should spin at least one wheel on each axle.

In 4wd the Jimny simply locks the two axles together (which is why you shouldn't use 4wd on grippy surfaces), so it isn't possible to spin the back wheels but not the front.

However, they tend to spin diagonally opposite wheels, so that an observer standing to one side thinks that just the back (or front) is spinning. (e.g. Clarkson claiming that Sir James May had a 3wd Sierra in that special)

Double however, the front hubs sometimes don't lock, or a CV has broken from being driven excessively in 4wd on tarmac, so as DrRobin suggests, check everything is ok by jacking up one front wheel, engaging 4wd with the engine running and trying to rotate the lifted wheel by hand- if everything is ok it won't turn.

Dipping a Jimny in salt water is another issue......

Thaks for input!

Took the car to a shop and they concluded that it not working, the front wheels are not engaged i 4-wheel mode.

Anyway there is sound klick when pressing the 4-W button and the indication light comes on after a few seconds. Could that narrow down possible faults?

And I have been told elsewhere that you need to drive the car a few meters in order to lock the system. Is that correct?

4wd should engage almost immediately, within 1/20th rotation of a tyre.
You should hear a clunk from each of the front hubs when you engage 4wd. Try it with the windows down. The engine needs to be running. If you don't hear this the most likely issue is one of the hubs sticking, which is an easy 20 minute fix.

Oki. Soo the vaccum system must be working in order to send the "go" signal to computor and to get the a steady 4WD indication on the panel. But the front hubs are stuck and does not commect to the shaft!?

Yes that is a possibility. You should be able to hear if one hub isn't engaging.

Its a clear sound from one front hub but not so from the other. Would it make the car 3WD or do this cancel the bouth front wheels?

You need both hubs to lock to get drive to either front wheel.

If one hub goes click= 4wd engages  and clack=4wd disengages, but not the other then there is probably a blockage in the pipes.


One sure fire way to block the ports in the hub is to replace the wheelbearing. Over enthusiastic greasing blocks the thin port in the hub with grease. (Both ports have to be clear, as it is air going in that pushes the hub when vacuum is applied to the other port)

get hold of a 100ml syringe of similar and use it to suck air out of the spigots on the hub one at a time, You should be able to move the hub and hear it click and clack. If you can, investigate the pipes, if you can't, remove the black outer hub, and then you can try blowing the ports clear. (if you don't remove the hub, the air has nowhere to go)

Then there is the possibility that someone crossed the pipes over. This one is trial & error until the hub locks when you select 4wd with the engine running. (The system only supplies vacuum for a few seconds to move the hub so you have to keep going from 2wd to 4wd every time you test it)

 

Thanks for the explanation. I don get this fully:

"If one hub goes click= 4wd engages and clack=4wd disengages, but not the other then there is probably a blockage in the pipes."

What will be the effekt on the car if only one hub "click"? I suspect that is what happens accoring to how it sounds.