4wd light flashing (1 Viewer)

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graysworld

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I have found a similar thread and posted to it but had no replies so wondering if a new post may generate replies.

I have a 1995 KZJ78 SX Auto gearbox (Japanese model). My 4wd light is flashing and the hub lock light is not working at all. I have only just bought the truck and so far Most things are working! So with the truck up off the ground the hubs appear to be locked. engaging 4wd drive and the front wheels turn. I have been told that because the electric hubs are unreliable someone could have somehow permanantly locked them. This has possibly confused the ECU and that is why the hub lock light stays off and the 4wd light flashes. Can anyone confirm this and indeed does anyone no of a fix to get the 4wd light to stay on? I guess I need to strip the hubs to see what is going on. I will do this is due course as I want to change all the seals and bearings and discs (rotors) and pads. Any help appreciated.

Regards Graeme
 
graysworld said:
I have found a similar thread and posted to it but had no replies so wondering if a new post may generate replies.

I have a 1995 KZJ78 SX Auto gearbox (Japanese model). My 4wd light is flashing and the hub lock light is not working at all. I have only just bought the truck and so far Most things are working! So with the truck up off the ground the hubs appear to be locked. engaging 4wd drive and the front wheels turn. I have been told that because the electric hubs are unreliable someone could have somehow permanantly locked them. This has possibly confused the ECU and that is why the hub lock light stays off and the 4wd light flashes. Can anyone confirm this and indeed does anyone no of a fix to get the 4wd light to stay on? I guess I need to strip the hubs to see what is going on. I will do this is due course as I want to change all the seals and bearings and discs (rotors) and pads. Any help appreciated.

Regards Graeme
Click to expand...

So I haven't had the exact problems you're having, but here are my thoughts based on some problems I have had and seen with these trucks.

The capacitors in the ECU can leak dielectric onto the circuit board which slowly eats away copper traces and vias. This can begin to cause all sorts of grief. ECU is behind/above the glove box and easy to remove, open and inspect. I recommend pre-emptively replacing the electrolytic capacitors even if they appear ok.

I ran e-hubs for years. When I first bought my truck, I took them all apart and followed FSM RM183E procedures very carefully as I rebuilt/resealed knuckles/hubs/brakes. The brushes were missing on a couple contacts, and I had to make new ones manually. I also used a special grease on the slip rings etc. in there. Dow Corning Molykote 44 if I remember correctly. They worked fine for 8 years, and just started getting a bit intermittent last winter. I think because they probably needed more grease put in.

Anyhow, I decided to scrap them and install manual hubs like most regular landcruisers have. This was a great move and I wished I'd done it long before. I really think this is your best option. Finding parts in Europe is probably not easy, but if there is a rusty old parts 60 series, or Hilux minitruck, you can use the spindles/hubs, freewheel assembly and all hardware from them. Its worth the effort and cost.

The other thing that can happen is one of the VSV's that switch the vacuum 4wd for the transfer case can fail. This has happened to me. I switched the vacuum hoses manually to make it work properly as I was off road at the time. I snagged a similar Toyota one from an emissions system to replace my failed one. Works great to this day.

So, hopefully that is some food for thought. There are also schematics (Japanese) for these trucks that we found. You can go through the wiring carefully too and figure out why things are happening as they are for you.

If you can't find rm183e or the schematics, let me know and I'll find links for you. On of the rm183e manuals is missing the section on e-hubs (someone didn't scan that part)....so you may have to find the other.
 
Even though my hub lock button does nothing I still press them both in when engaging the 4WD just to remind me to unlock the hubs

both buttons light up and stay on when pressed

the 4WD button only engages the transfer case which will make the front axles and drive shaft spin

if this is not working it will flash, thats what I found when I munted the vacuum lines off by accident

ill do an experiment tonight and see if I can make the 4WD button flash , Im pretty sure I have made this do it when pressing the hub lock button by accident while driving

sounds like because the hub lock button doesnt light up at all maybe this has been disconnected thats causing the 4WD light to flash, check power to the button ? dash is not to bad to pull off

I fitted "old blue " manual hubs work a treat and left everything else intact , just not plugged in to anything at the hubs now
 
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I junked the electric hubs a long time ago but I think the 4wd light would flash if they weren't engaged, or if you were going too fast for the 4wd controller to allow 4wd to be engaged. I thought that meant it wasn't switching the transfer into 4wd but I don't think I ever actually checked. After I had removed the electric hubs & chopped the wires that used to go to the hubs I just pushed in the hub button anyway & then it would shift to 4wd. So maybe it isn't something in the hubs but in the hub switch or controller? Try unplugging the hubs maybe?

As noted above most people replace the electric hubs with manual. I did that years back, & recently the 4wd control ECU started getting flaky about switching out of 4wd so I junked that too & just used a relay to switch the vacuum solenoid valves.

Cheers
Clint
 
Thanks for the replies, That gives me stuff to look for. On the replacing the hubs for manual ones. Are people saying there is no direct bolt on alternative? I have to source hilux parts as well as the hubs? No company does a straight replacement? Also how does the 4wd actuator work? Is there a vacuum operated solonoid on the gearbox? I am used to my Iveco which is purely mechanical and I am struggling to see how the vacuum system works so would appreciate an explanation.

Regards Graeme
 
graysworld said:
Thanks for the replies, That gives me stuff to look for. On the replacing the hubs for manual ones. Are people saying there is no direct bolt on alternative? I have to source hilux parts as well as the hubs? No company does a straight replacement? Also how does the 4wd actuator work? Is there a vacuum operated solonoid on the gearbox? I am used to my Iveco which is purely mechanical and I am struggling to see how the vacuum system works so would appreciate an explanation.

Regards Graeme
Click to expand...

There are bolt-on alternatives also. But each one is a compromise in one way or another. There is an adapter (Radd Cruisers) you can buy that allows you to bolt a normal free wheel hub onto your LJ78 hub assembly. I believe you end up with fewer bolts actually holding things together though. And there are some bolt on hubs from a company called AVM; they are known to be much lower quality and weaker than the Toyota/Aisin hubs. Another option is to modify the elec hubs so you can turn the internals manually with a hex key. Everything costs money.... I'm really happy just having an OEM manual setup now. Do some searching, as this topic has come up countless times and there is lots of discussion about pros/cons either way.

Regarding the t-case, the vacuum shift system is just a diaphragm with a vacuum nipple on either side. The diaphragm is mechanically coupled to the shift mechanism. Put vacuum to one side, it shifts in 4wd, put vacuum to the other and it shifts out. It's controlled by two electronic vacuum switching valves. These allow the electrical to control vacuum to the shifter when you press the button.
 
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Thanks again, Food for thought indeed. I am finding it difficult to believe being a new Landcruiser owner that Toyota have come up with a duff design! I know nothing is perfect but they seem to have taken a backwards step from the 60 series to the LJ 70 series. I presume the HJ70s do not have the same problems. does anyone have a list of part required to change to 60 series or hilux so that those manual hubs can be fitted. That said the Old Blue solution seems to be a good solution. So as I work my way through the list of jobs, I will decide on the best solution for me as I am based in the UK. I prefer everything to be manual as I am used to my old Iveco.

Regards Graeme

P1060039.JPG
 
It's not so much a 70 series thing as a JDM thing. Ex Japan Surfs, 60 series etc from the same era also got similar hubs.

I put a few notes in my build thread on the manual hub swap: Clints Cruiser Project - Page 2 - Offroad-Express

The reason doing it this way is popular & recommended is that the factory Aisin hubs on a lot of old Toyotas are actually a really good unit, they're usually very cheap to obtain, & swapping the complete hub is better than the more expensive bolt on solutions. Oldblue's conversion is good too though, as in std configuration the stock hubs are plenty strong.

Cheers
Clint
 
graysworld said:
Thanks Clint, useful information and good write up. Is this the correct hub? ebay link

Graeme
Click to expand...

That is nothing like the correct hub. Looks like it's for an IFS truck. Your best bet is to get used parts off an old beam axle Hilux from a wrecker or somebody that's parting one out, look for one with the stock steel bodied Aisin free wheeling hubs like in my build.

Cheers
Clint
 
Thanks again Clint,

I will look out for the correct year/beam axle model.

Regards Graeme
 
GTSSportCoupe said:
There are bolt-on alternatives also. But each one is a compromise in one way or another. There is an adapter (Radd Cruisers) you can buy that allows you to bolt a normal free wheel hub onto your LJ78 hub assembly. I believe you end up with fewer bolts actually holding things together though. And there are some bolt on hubs from a company called AVM; they are known to be much lower quality and weaker than the Toyota/Aisin hubs. Another option is to modify the elec hubs so you can turn the internals manually with a hex key. Everything costs money.... I'm really happy just having an OEM manual setup now. Do some searching, as this topic has come up countless times and there is lots of discussion about pros/cons either way.

Regarding the t-case, the vacuum shift system is just a diaphragm with a vacuum nipple on either side. The diaphragm is mechanically coupled to the shift mechanism. Put vacuum to one side, it shifts in 4wd, put vacuum to the other and it shifts out. It's controlled by two electronic vacuum switching valves. These allow the electrical to control vacuum to the shifter when you press the button.
Click to expand...
Hey, have you got any pictures of this? My transfer case won't engage and I guess the vacuum lines is where to start!

Thanks in advance!
 
The hose that splits into two to each vsv is the vacuum source. The other two hoses will engage or disengage 4wd depending on which one gets vacuum. Just connect vacuum source to one or the other using a small coupler.
 
clintnz said:
I junked the electric hubs a long time ago but I think the 4wd light would flash if they weren't engaged, or if you were going too fast for the 4wd controller to allow 4wd to be engaged. I thought that meant it wasn't switching the transfer into 4wd but I don't think I ever actually checked. After I had removed the electric hubs & chopped the wires that used to go to the hubs I just pushed in the hub button anyway & then it would shift to 4wd. So maybe it isn't something in the hubs but in the hub switch or controller? Try unplugging the hubs maybe?

As noted above most people replace the electric hubs with manual. I did that years back, & recently the 4wd control ECU started getting flaky about switching out of 4wd so I junked that too & just used a relay to switch the vacuum solenoid valves.

Cheers
Clint
Click to expand...
Any chance you could do some kind of write up about bypassing the ECU and going to a relay switch?

I'm making plans to convert to manual hubs, but my OCD won't tolerate flashing hub lock or 4wd indicator lights. I'd love to figure out how to get this to the point that the hub lock indicator either did nothing or stayed lit when the hub lock button was pushed (even though the hubs are manual so the button doesn't do anything) and the 4WD indicator was lit (not flashing) when I push the button. Completely bypassing the ECU and and controlling the 4wd indicator light would be one way. It sure seems like there should be a way to trick the ECU into thinking the hub lock mechanism worked so it gave a solid light. The hub lock indicator light would be misleading, so I could always remove that bulb from the dash, but if the ECU thought the hub was locked, then the 4wd indicator light would be correctly on (well... assuming the manual hubs were locked).
 
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