LJ70 2wd > 4wd switching query (1 Viewer)

Joined
Sep 28, 2020
Messages
2
Location
Malta
Hi,

I own a 1990 LC SWB (square headlight) running a 2LT and manual gearbox with front manual hubs.

I am having a problem to troubleshoot my 4wd switching issue, basically pressing my 4H button does nothing, and if I try to shift the lever to 4L to engage low range the 4WD light does NOT come on and low range is only engaged in my rear axle, my front axle spins freely.

I am thinking that it's the 4wd motor(actuator) attached to the gbox/tcase but I also a need to replace the relays and vacuum solenoids as they are all rusted, but since shifting manually to low range doesn't engage 4wd either I need to get that sorted first in order to troubleshoot the solenoid (4H) issue.

Also read somewhere that some models have a 4WD ECU. Any idea where to look for it ?

Any idea where to start please? :)

kylepacemt
 

GTSSportCoupe

2LTE abuser
Joined
Mar 23, 2012
Messages
7,310
Location
Victoria, BC, Canada
Hi,

I own a 1990 LC SWB (square headlight) running a 2LT and manual gearbox with front manual hubs.

I am having a problem to troubleshoot my 4wd switching issue, basically pressing my 4H button does nothing, and if I try to shift the lever to 4L to engage low range the 4WD light does NOT come on and low range is only engaged in my rear axle, my front axle spins freely.

I am thinking that it's the 4wd motor(actuator) attached to the gbox/tcase but I also a need to replace the relays and vacuum solenoids as they are all rusted, but since shifting manually to low range doesn't engage 4wd either I need to get that sorted first in order to troubleshoot the solenoid (4H) issue.

Also read somewhere that some models have a 4WD ECU. Any idea where to look for it ?

Any idea where to start please? :)

kylepacemt

It could be one of the vacuum switching solenoids for the t-case have failed. This is a common failure for the vacuum switch landcruiser t-cases. Try manually bypassing the VSV's and see if your 4wd works then.

This happened to me also, and I replaced the failed VSV with a used one from another Toyota's emissions system.

vsv-jpg.235303
 
Joined
May 21, 2006
Messages
428
Location
Rotoiti, New Zealand
Good advice above! Also check out this recent thread for some info & a couple of different fixes: Kzj70 transfer case problems

Work out which vac hose & solenoid is which & label them - it will make troubleshooting easier as you swap stuff around.

There is no 'motor' on the t-case to actuate 4wd - it is a vacuum diaphragm, get under & have a look, you'll be able to follow the hoses up to the solenoids.

Cheers
Clint
 
Last edited:
Joined
Sep 28, 2020
Messages
2
Location
Malta
Thanks a lot for all your replies. I will try that and get back to you with a result. Much appriciated 😀
 

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