4WD question!

Sorry for another question!

Right, the 4wd is not working on the Jimny, I have checked all the vacuum pipes and I think they are blocked where they go into the hubs. I'm in the middle of sorting that bit out.

While I was under the car I started to check other things out about the 4wd system (front of the car off the ground). When I select 4wd the front prop locks to the rear one, but the front drive shafts don't lock with the prop (hubs off) if you rotate one it does rotate the other side.

With 2wd selected if I rotate the front prop it does rotate the drive shafts but a slight resistance on the shafts stops them from rotating with the front prop.

Im not 100% how it is supposed to work but I thought with it in 4wd nothing should turn?

Could it mean that the front diff is worn and slipping or completely f****d?

Any help - guidance greatly received

Not quite sure what you are describing.

In 2wd, the hubs are free, rotating the propshaft by hand does nothing at the wheels, but the differential gears will turn and one of the halfshafts will turn, but you won't know which one.

In 4wd, the front prop locks to the back, and the hubs should lock. With one front wheel off the floor, you can't rotate it by hand. With both wheels off the floor rotate one by hand, the other will rotate backwards if the differential is working.


Could one or both of your hubs be working backwards because the pipes have been reversed?

I have traced the pipes and think they are back to front! so i'm going to run new pipes in while its all in bits. At the moment the jimny is up on axel stands with wheels and hubs off so the half shafts are visible, thought i would try to understand how it all works

with one wheel off the floor in 4wd and hub off, you can still turn the half shaft.

With both wheels off the floor in 4wd and hubs off, you can still turn the half shaft.

Regardless of the hubs working i thought the half shafts would lock with the prop as these are mechanical not vacuum?

Yet with the front prop NOT locked (2wd) when you turn the prop you can see both half shafts turning untill a slight resistance is put on them (ie you hold it)

I have done these tests to try and prove what is working, i.e half shafts aren't snapped, diff is actually in there, prop does connect to the half shafts. They might not be the right tests but this is whats making me think the diff could be worn.



I'm unsure how it all works so just trying to get my head round it all, feel free to cyber slap if i'm battering your heads as well :laugh: i'm new to 4wd mechanics so be gentle

the half shafts aren't snapped.

In 2wd, you an turn the propshaft.

With the differential working, the half shaft with least resistance will turn.(very unusual for both to turn)
If you jam one halfshaft somehow, the other will turn.

en.wikipedia.org/wiki/Differential_%28mechanical_device%29



If the vacuum pipes are crossed over, the hubs will lock in 2wd, and you won't be able to turn the propshaft by hand, unless a wheel is off the floor, and the wheel can rotate.
If just one hub has crossed pipes, possibly when the kingpins were replaced, it will never work.

I would select 4wd, then back to 2wd, and see if the prop will go round in 2wd.
Then I would swap just one hub pipes over, and select 4wd, see if the wheel can rotate, then go back to 2wd and see if the prop will rotate

Maybe a good film will help understand how a free diff works and make the proper tests in your case:

lol, thank you that man!