My four-wheel drive has stopped working, does this need to be fixed or can I just leave it as a 2wd?

After searching TW for questions asked in the previous posting I think my actuator fork might be broken is why it stopped engaging.

Can I just leave it as a 2wd and when I can afford it, get it repaired?

 

Yes

 

Probably. But it depends on exactly what is broken. If you're partially engaged in 4X4 there could be problems. Otherwise it is no different than just driving in 4X2 like you probably do 99% of the time anyway.

 

I'm not an expert certified auto mechanic but I don't see what harm it could cause. Hopefully someone with more knowledge of the inner workings of the actuator will chime in.

 

@blu92in99 @Marshall R @tacotoe thanks for everyone's reply, I don't use the 4x4 very often so I may just leave it till the wheels fall off.

 

This.
Most likely you'll be fine to just run in 2wd, but the sooner you get it checked out the better. Just in case.

 

I'm wondering how you came to the conclusion that a fork is broken, it would be unusual for that to happen with normal use.

 

which fork is broken? Transfer case or differential disconnect? If it's broken, it could shift around and cause damage no matter what position you decide to leave it in. Personally, I'd not chance that, as if it gets caught up on some spinning parts you will be out alot more cost than just a shift fork.

 

Do you agree with this list as a starting point for items to check, I'm hoping it may just be an open fuse:

1. Check to see that all body grounds are secure and have good contact, not corroded. Specifically, the rear side of the cylinder block (right side for V-6), left kick panel, instrument panel brace (RH), right kick panel.
2. 4WD fuse. 20 amp located in the lower dash fuse box.
3. Broken wires, loose or corroded terminals at connectors.
4. Fuse, relay block, engine compartment left, #2, 50 amp fuse.
5. 4WD rotary switch.
6. Problem with motor and/or limit switch in front ADD Actuator.
7. Sticking shift rod in Transfer Case Actuator. Remove cover and see if gummed up.
8. Problem with 4WD detection switch in Transfer Case Actuator. Remove switch and test.
9. Problem with 4Lo detection switch in Transfer Case Actuator. Remove switch and test.
10. 4WD ECU.

TESTING CONNECTORS
Individual wires and combinations to all the components have various test specifications and you would need the factory manual and a diagram.

As far as simple testing of voltage to the servo motor, the connector of the front ADD Actuator includes a red wire (terminal 1) and a black wire/white tracer (terminal 2). When the ADD servo motor is being driven to lock the differential (4WD switch turned 2H-->4H) there should be +12v measured at the red wire (terminal 1) with the black wire/white tracer (-) (terminal 2). The reverse polarity should be measured when the servo motor changes direction (4H-->2H selected) to disengage the ADD.

For the Transfer Case Actuator, there is a lavender wire (terminal 1) and a blue wire (terminal 2) included in the connector. +12v should be measured at the lavender wire (terminal 1) and the green wire (-) (terminal 2) when 2H-->4H is selected. When 4H-->2H is selected the reverse polarity should be measured.

 

That all sounds accurate minis the wire colors. The t-case has a blue and green wire going to the servo. I'd be checking electrical before tearing into the transfer case and checking shift rod, save that for last.

 

Thanks for that diagram, I miss my 1988 Nissan 4x4 King cab, with the 4-wd shift knob on the floor and without the electronics.

It seemed to happen right after replacing my coolant thermostat, which against my Haynes manual advice, I didn't disconnect the negative terminal to the battery, that and launching my Tacoma on some good bumps on I-95 repaving.

 

There are options! Swapping to a manual FJ case is a pretty popular option, especially if you need to purchase a transfer case and/or actuator. The FJ case can usually be had cheaper than just the actuator. I doubt you did any damage as a result of that thermostat maintenance, if you did that would be pretty impressive. Disconnecting the negative battery terminal is standard protocol for any instructions in a repair manual; same as putting on safety glasses or cracking a cold beer

 

See attached for the voltage readings you'll need to check to diagnose the 4wd electronics. Get yourself some meter leads with the skinny needle type leads to get behind the connector terminals for an easy and accurate reading.

 

I think the real cause may be not exercising my 4-wd enough, as the sandpit I usually use for decades is now a soccer field.

 

Thanks for that list.

 

wiping the contacts and clearing any potential dead spot on those little DC motors will prevent premature failure, it is unfortunate they've made it a requirement to use 4wd occasionally when you don't need it if you want to be able to use it later on. The days of manual hubs and a shift lever are long gone, even in full size trucks.

 

I just wanted to update this thread on what I feel is a temporary fix that has gotten my 4wd working again by getting under my Tacoma and tapping on the actuator with my palm.

This thread gave me information that lead me to try that highly technical technique to get the 4wd working again.

https://www.tacomaworld.com/threads/how-to-trouble-shoot-4x4-actuator.263525/

 

didn't check that link but pretty sure I get the basic idea! At work we sometimes refer to that as mechanically agitating and it most often requires a hammer of various sizes.

 

My "temporary fix" acted up by not engaging today, but if I put it in 4hi before starting it will engaging when it's started. I will try to solder the connection on the motor when I Fluid Film the frame in a few weeks.

 

I repaired it myself by replacing the plastic (crap) mounted on the side of the t-case called the actuator....be sure to set the clock correctly when installing replacement.
Never had issues with my old 82 4 banger 4wd.pu.
Loved that one too!