NEED HELP!! HJ75 Front Wheels not Turniong When in 4WD

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Apr 30, 2012
Hey guys, got a bit of a problem with my 1988 HJ75!

Went and had a bit of a mid-week play at a local track and broke my truck. Was nothing particularly challenging -

In both 2WD and 4WD, if I put too much load ie take off fast or hard, this terrible grinding noise comes from the back of the engine area/gearbox area. There is no burnt clutch smell or anything. Any ideas as to why? My first idea was that the rubber spaced gearbox support with fluid in the middle of the rubber was worn on one side and when I put a large amount of torque through the GB, compressing the fluid filled (leaking) rubber and possibly reducing the contact with the flywheel and clutch?

Also, my Front wheels when engaged in 4WD both high and low range are not working. I have discovered that my pinion seal not fully sealing - could this (lack of oil/less than full) within the diff be the cause?
Other things it could be? possibly broken CV/axle?

If one hub is not engaging, would both wheels not work when in 4WD

Help would be much appreciated as this is my daily.

Thanks ahead,

shifter not fully engaged or disengaged at t/case is my guess ...
play in front output companion flange?
Is the front drive shaft turning when 4wd is engaged? You need to isolate it between the front axle and transfer case.

Im not sure about having one hub engaged but I think its a big no no.
Is the front drive shaft turning when 4wd is engaged? You need to isolate it between the front axle and transfer case.

Im not sure about having one hub engaged but I think its a big no no.

YUp things start to BREAK :( when using only one HUB.

Jack it up and test it with all the wheels of the ground (on jack stands etc).

Check the universal joints for movement - when did you grease them last (yes they have nipples that need greasing and do not produce milk )

Check the fluid levels of everything xfercase and geabox and diffs also (and the colour).

Probably going to have to pull both front hubs off and check them both also - I wonder if one is DRY or got mashed up.
Last edited:
How are you testing the front wheels arent turning in 4wd?

Had a similar issue and it was the big no no, one hub locked the other didnt so I though the drive wasnt working. It was but because one wheel was free all the drive went to that wheel. I think.

I reconditioned both lockers (took em off, cleaned em up re greased and returned them to the vehicle) 4WD worked again,

I am not sure about the grinding noise but are your universal joints okay? I redid mine last week (took 2 hrs for the rear and about 1.5 for the front, I got better at it as I went) The front one was not too bad, but on its last leg the rear most one was p@#cked. Rusted, bearings gone and pretty dry really, but it made a noise only when I reversed hard. But I did have a vibration to go with it.

when you grab the drive shaft where you think the noise is, can you push it up and down or is it solid. Could be a bearing issue as well, but most likely it will be something minor that a dab of grease will fix. Its a Troopy
ummm, BS
you can drive with one hub locked if you are so inclined with no side effects other than no front end pull off road.
not recommended of course
seriously, someone inform me of the damages?
<front drive engaged>
the shaft turns as if both hubs are locked.
the pinion turns as if both hubs are locked
the axle shafts and birfs are turning as if both hubs are locked.
all the power goes to the unlocked hub end (if the front end is not a locker style)
the power is still divided between both axles (if the front end is a locker style)
50% goes to the hub that is locked, 50% goes to the hub that is unlocked

<front drive disengaged>
power from the road goes back through the wheel to the hub
the hub that is locked transmit power to the center unit.
the hub that is unlocked sits there
the power from the locked hub enters the center unit and stops there since the unlocked hub allows the center unit to lose its ability to transmit power to the pinion and drive shaft.

if you have an auto locker in the front then the power will flow back to the drive shaft and since the front output is disengaged that is where it stops.

sorry guys but that is an old wives tale.

carry on

Users who are viewing this thread

Top Bottom