HZJ 78 series 4wd engagement issues.

Submitted: Saturday, Apr 22, 2017 at 15:02
ThreadID: 134707 Views:2011 Replies:5 FollowUps:2
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For a while now I've noticed that the 4wd indicator light in my Troopy (78 series- 2000 model.) doesn't come on when I move the little lever into 4wd- but I figured the light had just died....... Then last week I got stuck in some sand and noticed that the front wheels weren't driving (yep- I had the hubs engaged...)
So today I crawled underneath and the linkages all seem connected up. BUT I noticed that the wires that go from the alloy housing just where the lower part of the linkage engages with the shaft that makes it go into 4wd, is disconnected at the round plug just above the gearbox. And I can't see anything to plug it in to.
So here's my questions:
1. Can anyone tell me where the wires from the alloy housing are supposed to go to ?
2. Is there anything electrical about 4wd engagement ? Or is that wire just for the indicator light ?
Sorry if I haven't explained it very well.....I'll have a go at attaching some photos.
Thanks in advance for any help.
Cheers,
Martin
P.S. I suspect that the light stopped working after the local garage installed a new clutch for me........
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Reply By: passionfruit - Saturday, Apr 22, 2017 at 17:29

Saturday, Apr 22, 2017 at 17:29
There is nothing electrical needed to engage 4wd on that model. Sorry Glenn.
AnswerID: 610442

Reply By: Member - Phil G (SA) - Saturday, Apr 22, 2017 at 23:30

Saturday, Apr 22, 2017 at 23:30
" I suspect that the light stopped working after the local garage installed a new clutch for me"

Most likely that is what happened. There is a switch that sticks out of the transfer housing and tells the dash light that 4wd has been engaged. That switch has been smashed and the wires have nothing to connect to. It is hard to access so most people just forget it existed as it doesn't affect engaging 4wd.
The activation itself is purely mechanical.

As for 4wd not working, you need to get it checked out. Most likely cause is a freewheeling hub has been reinstalled incorrectly and is not working. Jack up a front wheel and test that the hubs engage.
AnswerID: 610447

Follow Up By: Member - Phil G (SA) - Saturday, Apr 22, 2017 at 23:40

Saturday, Apr 22, 2017 at 23:40
Just to expand on how you test that the hubs and 4wd are working, here is what I do:
Jack up drivers side front wheel. Transfer in 2wd and hubs not engaged. Gearbox in first gear.
Rotate wheel and check that front prop shaft does not turn.
Engage passenger side hub and rotate wheel. Again front prop shaft should not turn.
Engage drivers side hub as well and rotate wheel. Prop shaft should now turn.
Engage 4wd high and attempt to rotate wheel again. It should now be impossible to rotate the wheel.
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FollowupID: 880379

Reply By: Nitram - Sunday, Apr 23, 2017 at 07:54

Sunday, Apr 23, 2017 at 07:54
Thanks Phil and Glen,
I guess it was just wishful thinking, when I saw that wire disconnected, that there was something electrical in the engagement of 4WD, and easy to fix.
The round switch on the side of the housing isn't damaged, but the wires coming out of it go up 4 or 5 inches to a round plug that isn't plugged into anything. So I guess that's why the light doesn't come on, but that's just a coincidence. I do wonder what has become of whatever it used to plug into......
But thanks for directing my mind to the bleedin' obvious.......:-) I now see that when the lever is put in 4wd (hubs disengaged) the front drive shaft doesn't turn. Therefore 4wd IS engaging. I also find that with the lever in 2wd, and the hubs engaged, the front shaft turns freely- showing that the free-hubs are not engaging.
Come to think of it, the same mechanic who replaced the clutch and seems to have disconnected the 4wd indicator light, also replaced the front wheel bearings. I think that the only time in recent history (I've had the car 5 or 6 years) when the front has been messed with.
Anyway, now I need to investigate why the freehubs are not engaging the front driveshafts......... The dial rotates through its full movement and seems smooth enough. I'll start dismantling and see what I find.
Thanks for your help so far.
Cheers,
Martin
AnswerID: 610453

Reply By: Nitram - Sunday, Apr 23, 2017 at 20:51

Sunday, Apr 23, 2017 at 20:51
Well after a Sunday spent under Troopy, I can now report that Phil was pretty close to being on the money. :-)
The RHS freewheel hub was full of all the rust and crud under the sun and was not allowing the sliding collar to slide along to engage with the spline. Because I don't have locking diffs, both front hubs need to be driving in order for them to make any contribution to getting some traction.
I'm not 100% sure that mine was previously put together correctly (one of the springs seemed not to be quite right) and I got a lot of help from various YouTube information clips on the subject. Some of them were a bit light on in spots, but overall they helped and with them the rebuild job wasn't too difficult, if fiddly and a bit filthy. This YouTube video was really good and gave a complete and accurate description of the job: https://www.youtube.com/watch?v=-mygIDZlne4
I still don't have a 4wd indicator light on the dash, and if anyone can tell me where to find whatever my wires from the 4wd engagement shaft housing are supposed to plug in to, I'd appreciate it.
Another thing of interest is all the clanking and clicking from the front end that happens when steering tightly when in 4wd. Is that normal ? I've read of the wheels getting "wound up" when using 4wd on tar, which makes sense. But since I don't have locking diffs I wouldn't have expected it to be an issue.
Anyway, It's good to have 4WD drive again, and hopefully I won't get stuck (again !) next time I go bush !
Thanks again for the help,
Cheers,
Martin
AnswerID: 610479

Follow Up By: Member - Phil G (SA) - Sunday, Apr 23, 2017 at 21:59

Sunday, Apr 23, 2017 at 21:59
Hi Martin,
Its great that you came back to us with what you found. All too often the regulars on the forum offer suggestions and never hear from the original poster again. So thanks for that.

Those wire are disconnected so you won't get the 4wd dash light. You can try connecting them, but in the case of an 80series that we owned that had the same problem after a clutch replacement, the connectors on the switch were damaged so the wires couldn't connect.
Hard to find good mechanics these days who know about rigid front axle landcruisers. All they seem to do these days is change the oil and filters and look at the computer. Seen the "FWH not working" maybe half a dozen times on club trips over the years. Usually reassembled wrong. It can be dangerous too - you engage 4wd and expect it to work down a steep slope and before you know it, the engine braking is not working.
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FollowupID: 880400

Reply By: The Bantam - Tuesday, Apr 25, 2017 at 11:22

Tuesday, Apr 25, 2017 at 11:22
far from uncommon for " normal mechanics" to get things wrong on 4wds.

Incorrect assembly of free wheeling hubs is common .... I've had such an expeience.

The correct tensioning of front wheel bearings is another ....... many normal passenger cars can be adjusted by hand ..... 4wds the bearings are large and should be preloaded with the prescribed procedure using a torque wrench and a large socket .......

there are other matters of detail that should be understood.

ya realy need to take 4wds to some one who understands them.

Cheers

AnswerID: 610534

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