4wd issues

[shotgun_willie]

Happy thanksgiving y'all and thank you for taking time to help out with my 4runner issues.

I've got a 1997 4runner w/ 5 speed and 4wd. The 4wd has always seemed to work and the light would come on when engaged; however, yesterday I put it in 4wd and the light did not come on. 4wd lo and the same thing. First of all I'm trying to figure out if just the light is out or if it is not engaging.

I thought that it felt like the truck was in 4wd and in 4 lo I was definitely in the low range. I need a more sure-fire way to decide whether the 4wd is engaging or not. Any suggestions for diagnosing the problem and then trying to fix it once its diagnosed?

Thanks in advance and I apologize if this has been covered before, I was having trouble finding what I was looking for in the search.

 

[Kenworth]

Well easy way would be jack front end up to get wheels off ground engage 4 wheel drive see if wheels free wheel or not?

 

[GVL]

Rev it to about 6000 RPM then slam it into gear and see how many wheels spin. Just kidding of course, I know I can definitely feel both 4L and 4H particularly when initiating a turning from a dead stop.

It wouldn't surprise me at all if it was just the light though, I'm starting to lose all kinds of indicator lights on my 2000. A light bulb replacement day is in my near future.

There is a fantastic "Replacement Bulb Part# List" thread on here if you need it.

 

[fourwd1]

Pay attention when you start the vehicle, one of the 1st things that happens is a dash light check, see if the 4WD light lights up, if not it may be the bulb.

 

[shotgun_willie]

Good call on starting the car and checking for the light. It does not come on when I start the veh so I'm hoping it's the bulb.

 

[TheDurk]

Good call on starting the car and checking for the light. It does not come on when I start the veh so I'm hoping it's the bulb.

Actually, it was a bad call. The 4WD light, at least on 5-speeds like ours, does NOT come on with key on before start.

You can feel if 4wd is engaged by driving in curves on asphalt at low speed. Thirty feet is all you need to feel it bind in 4wd and that won't hurt anything.

Beyond that, here is my standard post for VSV/ADD diagnosis:

VSV’s/ADD
Don't guess at it, troubleshoot! Start at the twin VSV's (Vacuum Switching Valves) on the driver fender wall. There are two long vacuum hoses that come up from the diff, one goes to each VSV. Check to see that one of the two hose nipples on the VSV’s has vacuum (engine running, 4WD NOT engaged. If no vacuum either side, check the check valve going to the intake manifold and look for loose hoses or a hole in the reservoir. If there is vacuum going to one hose, then put it in 4WD. See if the vacuum switches to the other hose. If it does, and no 4WD, problem is the diff actuator or the line to the diff. If it does not, then just switch the hoses and you should go into 4WD. This confirms diff is okay. (Mark the hoses first so you know which belongs where!)

OK, switch them back. Then use a test light to see if electrical signal from the TC also switches sides of the VSV. If it does not, problem is the TC, the switch on the TC, or the TC actuator, or its wiring back to the button (last two for non-J shift only). If it does, but the vacuum does not, the problem is the VSV itself.

I start troubleshooting at the VSV's because you can figure out where the trouble is without having to climb under the truck. [None of this applies to '01-'02 which have an electric actuator.]

 

[IBallEngineer]

Actually, it was a bad call. The 4WD light, at least on 5-speeds like ours, does NOT come on with key on before start.

You can feel if 4wd is engaged by driving in curves on asphalt at low speed. Thirty feet is all you need to feel it bind in 4wd and that won't hurt anything.

Beyond that, here is my standard post for VSV/ADD diagnosis:

Yeah, my friend is wicked smart!

 

[TheDurk]

Yeah, my friend is wicked smart!

Yeah, so wicked smart I called out a mod. (Didn't realize it at the time.) My big mouth is always getting me into trouble. Sorry, [MENTION=1857]fourwd1[/MENTION], I was overly snarky. But that light is not part of the test.

 

[Jon]

Simple red neck dirt road test.... Drop the hammer and let off... how many marks did you leave?

 

[Eric J. Robertson]

Actually, it was a bad call. The 4WD light, at least on 5-speeds like ours, does NOT come on with key on before start.

You can feel if 4wd is engaged by driving in curves on asphalt at low speed. Thirty feet is all you need to feel it bind in 4wd and that won't hurt anything.

Beyond that, here is my standard post for VSV/ADD diagnosis:

You say "BIND"
When i engage 4wd on pavement i can feel the tires bite the road and it ins't smooth. Is this normal? I want to say it feels like someone did a rear axle swap with diferent gears. The weels are spinning at diferent ratio's. It "feels" like mind you. First 4runner so im not sure what is normal.

 

[TheDurk]

You say "BIND"
When i engage 4wd on pavement i can feel the tires bite the road and it ins't smooth. Is this normal? I want to say it feels like someone did a rear axle swap with diferent gears. The weels are spinning at diferent ratio's. It "feels" like mind you. First 4runner so im not sure what is normal.

Yes, that is normal in full 4wd, as opposed to AWD, or all-wheel drive (an option the OP and I don't have. True 4wd spins the front and year drive shafts together with no give, so the tires sort of fight each other on curves on surfaces with no slip. You should not operate in full 4wd on such surfaces, only on dirt, snow, sand or mud that allow some give in rotation. Your feel is accurate, as on curves the inside wheels want to do fewer turns than the outside wheels.