4WD not working?

[spencergt66]

Hi Im new to this site have a few dumb questions. I just bought a nice clean well kept 94 4runner sr5 v6 everything seams to be in great shape the only issue I see is that the 4wd doesn't seam to engage. Every toyota I have had has had locking hubs this does not, I would assume there is some type of axle disconnect involved in the front end? Also does thins thing have a 4wd indicator? I cant remember if my old truck did or not I thought so but i see no light coming on in this one. :thanks:

 

[spencergt66]

Hi Im new to this site have a few dumb questions. I just bought a nice clean well kept 94 4runner sr5 v6 everything seams to be in great shape the only issue I see is that the 4wd doesn't seam to engage. Every toyota I have had has had locking hubs this does not, I would assume there is some type of axle disconnect involved in the front end? Also does thins thing have a 4wd indicator? I cant remember if my old truck did or not I thought so but i see no light coming on in this one. :thanks:

Well i did some searching and some checking and all the fuses look good all the vacuum lines are hooked up (it does have ADD) is there a switch on the tcase or other things I need to check?

 

[Geolander]

Hi Im new to this site have a few dumb questions. I just bought a nice clean well kept 94 4runner sr5 v6 everything seams to be in great shape the only issue I see is that the 4wd doesn't seam to engage. Every toyota I have had has had locking hubs this does not, I would assume there is some type of axle disconnect involved in the front end? Also does thins thing have a 4wd indicator? I cant remember if my old truck did or not I thought so but i see no light coming on in this one. :thanks:

Yeah, you have automatic locking hubs, though you can retrofit manual locks if you prefer those. You should have a 4WD light that comes on, though on mine it can take a couple seconds before it shows up. Mine is a manual though, so if you have an automatic it may be a bit different. I'm not really sure.

 

[Lola_Runner]

I had a very similar problem before on a old 89 Toy Pickup. A mechanic had put the transfer case in wrong and the 4wd shifter wouldn't even move. If that is the same problem your having that could be a answer for you. Also yes when the Runner is in 4wd it does have a indicator light that turns on.

 

[SUBTEGRAL]

The "4WD" light will appear in the far upper right-hand corner.

Your 4WD is not engaging AT ALL?

how's 4LO feel?

** Remember, to unlock your auto hubs, you must put it back into "2HI" and then back up 10 to 20 feet until they unlock.

 

[spencergt66]

The "4WD" light will appear in the far upper right-hand corner.

Your 4WD is not engaging AT ALL?

how's 4LO feel?

** Remember, to unlock your auto hubs, you must put it back into "2HI" and then back up 10 to 20 feet until they unlock.

Mine is a manual, the 4h and 4L both engage 4l is definitely working but when I turn I feel no binding or see no 4wd light

 

[SUBTEGRAL]

Every toyota I have had has had locking hubs this does not,

Now I'm confused ..

 

[spencergt66]

Now I'm confused ..

What s the confusion? My 4 runner that I have Now has the add I have never had a Toyota with this set up all the toyotas I have had were 4x4 with manual locking hubs there was no guessing if it was in 4wd.

My 4 runner has no light coming on and doesnt feel like it's in 4wd, I can make a sharp turn on pavement and there is no binding of any sort in the drive system

Hope this clears it up

 

[SUBTEGRAL]

My 4 runner that I have mow has the add I have never had a Toyota with this set up all the toyotas I have had were 4x4 with manual locking hubs there was no guessing if it was in 4wd.

huh?

 

[spencergt66]

huh?

What are you confused about?

 

[Geolander]

Now I'm confused ..

All he meant was that he's never had a Toyota with auto locking hubs before. All his others have had manual hubs.

Mine is a manual, the 4h and 4L both engage 4l is definitely working but when I turn I feel no binding or see no 4wd light

Not sure about the binding, but it could be that the bulb for your 4WD light is burnt out. Are you positive that the 4wd is actually engaging? The only way I can think of to be sure is to get at least one front wheel off the ground and see if it spins when you hit the gas.

 

[spencergt66]

All he meant was that he's never had a Toyota with auto locking hubs before. All his others have had manual hubs.



Not sure about the binding, but it could be that the bulb for your 4WD light is burnt out. Are you positive that the 4wd is actually engaging? The only way I can think of to be sure is to get at least one front wheel off the ground and see if it spins when you hit the gas.

Well whenever ive had a truck in 4wd on the pavement when you turn tight the front end seams to bind cause everything is trying to turn as 1.

Im about 90% sure that 4wd is not engaging but I think just the switch may be bad on the Tcase. I am in the middle of moving so I have none of my tools with me or a place to work so Im guessing this may have to wait a little bit :redbrick:

Looking over the wiring schematic the switch will close (on the T-case) when put in 4WD activating the relay for the ADD switching the vacuum supply to the pod on the axle when the 4WD is active and the shift dog for the front axle is engaged it will also activate a switch on the axle that turns the light on the dash indicating that 4WD is on

I can try a few things jump the switch at the axle to see if the light works and also jump the switch to see if everything will activate to lock in the front end. Or if i get really lazy i could just swap the vacuum lines on the 2 switches on the pass front inner fender to lock in the front end I may mess with this tomorrow to pin point my issue

 

[SUBTEGRAL]

Mine is a manual,

I took this to mean MANUAL LOCKING HUBS... but you say he has auto-locking hubs .. and now he agrees with you .. I guess his "manual" was referring to his transmission (don't know why his transmission would come into the conversation)

 

[90 t4r]

im having the same exact problem no light and no 4wd ive checked all the vacuum lines and they are all fine so if it does end up being ur switch i would be interested in knowing how you tested it so i can c if thats what is wrong with mine

 

[Geolander]

I took this to mean MANUAL LOCKING HUBS... but you say he has auto-locking hubs .. and now he agrees with you .. I guess his "manual" was referring to his transmission (don't know why his transmission would come into the conversation)

Yes, manual was in reference to the transmission. I only brought it up because the auto and manual shifter assemblies for the transfer case look different on the 2nd gens. The manual has a J-pattern shifter while the auto has a straight pattern. I don't know if the mechanicals and warning systems are the same between the two, but I figured it was worth asking.

Auto shifter assembly:

Manual:

 

[Vegas4Runner]

Well whenever ive had a truck in 4wd on the pavement when you turn tight the front end seams to bind cause everything is trying to turn as 1.

Im about 90% sure that 4wd is not engaging but I think just the switch may be bad on the Tcase. I am in the middle of moving so I have none of my tools with me or a place to work so Im guessing this may have to wait a little bit :redbrick:

Looking over the wiring schematic the switch will close (on the T-case) when put in 4WD activating the relay for the ADD switching the vacuum supply to the pod on the axle when the 4WD is active and the shift dog for the front axle is engaged it will also activate a switch on the axle that turns the light on the dash indicating that 4WD is on

I can try a few things jump the switch at the axle to see if the light works and also jump the switch to see if everything will activate to lock in the front end. Or if i get really lazy i could just swap the vacuum lines on the 2 switches on the pass front inner fender to lock in the front end I may mess with this tomorrow to pin point my issue

Any luck? What did you find? I am dancing with this same issue but lack some of the know-how to really pinpoint the problem. I like your methodology and if it helps you find the problem it will be worth copying. Please post your results.
Thanks,

 

[4Reak Show]

Old post but might help somebody

Just had my ADD act up. Hadn't ran it in awhile and sh!t got gummed up. Replaced both switches for around $100 and all is good.
Best way to test for sure 4WD is a hoist with all the tires off the ground. I do like the binding test but it may not be conclusive.

Transfer case switch Toyota P/N: 84222-35060
Front diff switch Toyota P/N: 84222-35070

Transfer case grounds the relay (you'll hear a relay in the dash click when physically shifting the transfer case from 2-4WD, even key on engine off)
It also allows the Front diff switch to ground so when the ADD shifts and physically engages it turns the light on.
Relay should then switch the VSV set to change the applied vacuum down at the diff.

Mine was electrical symptom from a mechanical switch so moral of the story is to exercise your 4WD once a month probably.

 

[mikedks]

Just had my ADD act up. Hadn't ran it in awhile and sh!t got gummed up. Replaced both switches for around $100 and all is good.
Best way to test for sure 4WD is a hoist with all the tires off the ground. I do like the binding test but it may not be conclusive.

Transfer case switch Toyota P/N: 84222-35060
Front diff switch Toyota P/N: 84222-35070

Transfer case grounds the relay (you'll hear a relay in the dash click when physically shifting the transfer case from 2-4WD, even key on engine off)
It also allows the Front diff switch to ground so when the ADD shifts and physically engages it turns the light on.
Relay should then switch the VSV set to change the applied vacuum down at the diff.

Mine was electrical symptom from a mechanical switch so moral of the story is to exercise your 4WD once a month probably.

I will say this about the whole ADD nonsense, just get rid of it. Mine acted
up at the worst time last winter, the one VSV switch would engage the 4WD, but the second VSV was dead, would not come out of 4WD cleanly.
Had to manually switch the VSV connectors to get the damn thing back to
2WD. You know what I did? the ADD delete mod, look it up but I'll give you
the Cliff notes version. On the front of the differential is the ADD axle disconnect, its a small rectangular cover secured with 4 bolts, looks like a diaphram on it, one electrical connector, and a couple of vacuum lines. After you disconnect the vacuum lines and the electrical connector, pop off the cover. You will see that the back of the cover has a rod that a big metal
fork slides back and forth on. The fork slides onto a disconnect collar on the axle that also slides back and forth. When the system is operational, the VSV push and pull the collar back and forth engaging/disengaging the
front axle. The vacuum modules can and do fail. What the mod does is to
eliminate all the vacuum modules and lock the axle into place. I believe if
the collar is pushed to the left, the axle is locked. To hold in place, the mod has you slide the fork over to the left, than lock in place by putting a
small hose clamp on the slider shaft. This will permenantly lock the ADD axle disconnect collar in place and you can chunk the VSV's.

As I said, do an internet search for the mod, it's easy and will give you
some piece of mind.