80 Series Transfer Case

[Citroënbender]

“On the tools” again to help a mate out.

A somewhat modded later 80 series has presented in 2WD only, with H/L sometimes difficult to engage or disengage. I’ve found the following web page a good start for information, but hoping a couple of dumb questions can be answered for me. Really need a repair or at least final diagnosis (from component testing) by Monday business hours.

Q1: Who actually makes the transfer case (ie, what brand)?
Q2: Are they shared with any other vehicles (for economical parts sourcing)?
Q3: Is Neutral (RWD) a deliberate position or incidental only?
Q4: Is the H/L range actuation wholly physically independent of the diff status?

Hoping it’s a simple fix. There are a number of aftermarket modifications of different ages; lift kit, onboard compressor and rear air locker, remote central locking/immobiliser, head unit, multiple extra lights and power outlets… I realise it’s possible one of these has compromised the power supply or wiring route. At least it’s analogue (electromechanical).

[Citroënbender]

I had a couple of hours to poke at this last night. Supply voltages and switchgear all seem good. Moving down to the transfer case for deeper investigation…

At least one of the plunger switches isn’t working; moreover a special mention to the person who broke its connector on the harness then surreptitiously “glued” it all back together with black RTV. I think it’s a fairly common Toyota plug so a used switch and pigtail shouldn’t be impossible on Monday, just expensive.

The actuator motor which is supposed to lock the centre diff doesn’t run when a test that’s supposed to make it work, is applied. Its internal resistance seems on spec and with no shorts to ground. This makes me suspicious of the actuator unit’s earthing, which is supposed to toggle based on which setting the diff is on. I still need to hot-wire the locking actuator motor to see if it runs.

Googling also found a thread on IH8MUD where a fellow (amateurishly) pulled a transfer case apart, he wasn’t very technically minded and there weren’t any “here it is all laid out” type photos and the thread petered out after five pages with no reassembly of the case. It may be that I’ll have to grit my teeth and look at YT for better clues. IMO a lot of those type videos need heavily editing down to the guts of their topic.

[aussiblue]

Nothing on this guys channel of use https://www.youtube.com/playlist?lis...dQuhnjyyL-c1EF ?

[Citroënbender]

Could be, he’s one of the IH8MUD crowd (for whatever reason, my mind often merges them with the Pirate 4x4 forum…).

As I’d mentioned, videos are usually my last choice - but it may be my only choice.

[MrEL]

Smartest thing to do with 80 series is fit a part time 4x4 kit.
Fixes the problematic wiring dramas , improves performance and turning circle and improves fuel economy.

[Citroënbender]

Interesting things to read about, thanks. It’s indirectly helped me identify the transfer case family (HF2A). Front diff was just rebuilt and freewheeling hubs fitted - but no ABS sensor relocation mentioned. Hmm. It already has the discretionary centre diff lock modification.

Constraints of time mean it’s probably going out the door tomorrow afternoon with everything working except the centre diff. It’s dependably 2WD right now, front driveshaft is free-spinning. Apparently the upcoming trip is bitumen only, so it is likely to return in the new year for rectification.

[Hulsty]

Like your finding, its pretty common for the 4x4 actuator or system to fail. On Mates cars they have swapped out for a base model case which is manually shifted or done the part time conversion.

[Citroënbender]

To wrap up for now, yes, gone with a cheery promise to return in the new year. Thanks for the pointers in this thread; if it becomes my problem again I’m off to a running start.