KZN185 Center Diff Won't Lock

[PedRac3r]

Hey guys, new to this 4WD stuff but no stranger to cars/motorsport. Picked up a standard 96 Hilux Surf, 1KZ-TE, auto, few miles on the clock it seems to go alright. Only problem I have is the 4WD and center diff isnt working as it should. I can press the button on the transfer lever and it will engage the front wheels (no center lock, as it should), but going from H2 to H4L or L4L, the center diff wont lock or engage the front diff. I can get the front diff to hook up if I press the button on the transfer lever when Ive selected H4L or L4L, but still no center diff lock.

Googled this for a few hours without much luck. Ive had a quick look underneath at the wiring loom and plugs, everything seems intact, no corrosion on any of the plug contacts etc. Anybody got any other ideas, or had this problem before?

Thanks in advance.

[BlakeNZ]

how can you tell the centre diff is not engaging?

[PedRac3r]

how can you tell the centre diff is not engaging?

The orange light between the 4 green wheels isn't illuminated on the dash, and when I took it out to the beach (which is when I noticed there was an issue), I got stuck and only one rear wheel was spinning, which would confirm that the center diff is not engaging.

[mudsurfv6]

centre diff??

[mudlva]

Vacuum on trans box is faulty

[mudbugga]

Electric actuator on transfer most likely seized. Very common with them.

[PedRac3r]

Is there an easy way to test before I go looking for a replacement?

[PedRac3r]

I can hear the electric actuator working and the front hubs engaging when I press the button on the transfer lever, but when shifting the transfer lever down to H4L, nothing happens, can't hear the electric actuator working. So what tells the actuator that the transfer level is in H4L? Is there an internal sensor in the transfer case?

[rokhound]

Ctr diff on these is as weak as pig shit. But when they detonate, you will usually notice it during normal driving as the ctr diff will seize up. Go looking for the easy stuff first though as suggested. I did a write up on replcing a ctr diff in one of these 7ish years ago, but I have no idea where it is now, I think it was on prado point.

[tallsam66]

how can you tell the centre diff is not engaging?

The orange light between the 4 green wheels isn't illuminated on the dash, and when I took it out to the beach (which is when I noticed there was an issue), I got stuck and only one rear wheel was spinning, which would confirm that the center diff is not engaging.

I may be wrong but I thought when centre diff was locked it ensured the front & rear driveshafts would spin at same rate ... it doesn't effect the individual diffs. A locker in each diff will determine that.

[rokhound]

how can you tell the centre diff is not engaging?

The orange light between the 4 green wheels isn't illuminated on the dash, and when I took it out to the beach (which is when I noticed there was an issue), I got stuck and only one rear wheel was spinning, which would confirm that the center diff is not engaging.

I may be wrong but I thought when centre diff was locked it ensured the front & rear driveshafts would spin at same rate ... it doesn't effect the individual diffs. A locker in each diff will determine that.

Yes which would mean he should have one rear and one front wheel spinning.

[PedRac3r]

I may be wrong but I thought when centre diff was locked it ensured the front & rear driveshafts would spin at same rate ... it doesn't effect the individual diffs. A locker in each diff will determine that.

Yes which would mean he should have one rear and one front wheel spinning.

Thats correct, when the centre diff is locked, front and rear driveshafts will spin at the same rate. When the centre diff is not locked it can change the bias between front and rear axles, so if it sent all drive to the rear (or front) you would potentially only have one wheel spinning, which is what happened to me.


Happy to say though I fixed the problem, and it was very simple and easy in the end. Turns out there is a sensor right on top of the transfer case, was just out of sight, that was unplugged. Plugged that back in and everything worked as it should. Thanks for everyones input.

[hachi_roku]

Shouldve just brought a landcruiser