4wd is not working

Got my roommate to watch my front tires as I spun out in a snowy parking lot. The back wheels spun, the front ones didn't. When I last used 4wd a month earlier it worked fine, but I did note that the 4wd light didn't illuminate (assumed it was a wire that had come loose a week earlier).

Pulling the lever into 4wd feels exactly the same as it did before. I didn't hear anything that sounded out of the ordinary and there wasn't more or less resistance then when it worked. But it doesn't change into 4wd. There isn't any check engine lights on, and other than the 4wd not engaging all seems fine.

What are some common causes of 4wd not working? What should I check to narrow down the issue?

 

Actuator on the differential tube is one reason.

Assume you have a j shift since you mentioned pulling a lever.

Test the actuator to see if you hear it engage/disengage.

 

Yes, its the manual transmission so no button for me. Is the actuator on the transfer case

 

Read my post.

 

When I engage 4wd and try to turn the driveshaft manually it is locked in place as it should. Does that mean my actuators are okay?

 

Are the vacuum hoses the same for the 4 cylinder and v6 as far as the 4wd system is concerned?

 

Yes

The only difference is the input gears when comparing an I4 transfer case and V6 transfer case.

 

Crawled under my vehicle today, it was gross being winter + snow + oil crud + being 12 degrees out. Took some photos before my feet went completely numb (I miss California). I tried to take photos of hoses that looked stressed, cracked, or could be problematic, since the vacuum system can be a bit sensitive.

Does anyone have a vacuum hose diagram for a 3rz-fe + manual transmission 4runner? Its difficult to tell what hoses go without tracing them all the way back. The photo that looks like a hose attaching into a black disc gave me hope that that was my issue, because as you can see it looks a bit loose and frayed.



The two photos above were taken in a spot that was hidden under the skid plate. The black disc is close-ish to the steering rack, hopefully it is related to the 4wd because that looks like it might be the source of my problem if it is.

Both the hoses in the photo above look slightly cracked. The photo below is a close up from the side that shows how there are cracks forming around where they fit over the plastic nub (for lack of a better word).

The last two photos were taken in the engine compartment with the hood open. The location is on the drivers side, close to the drivers wheel well. Better view of hoses.

Also in 4HI I cant turn the front driveshaft by hand but I can turn the front wheel by hand.

 

Okay, now it got really strange. At a light I put it into 4wd and the 4wd started working again- dash light and all. I don't understand what is happening, I poked around under the hood before this but I didn't do anything to it, and it just started working like nothing happened. What is going on?

I haven't tried taking it out of 4wd because I'm afraid it wont let me go back into 4wd, and I really need it right now

 

Picture #1 & 2 definitively show that vacumn hose is a problem. While I know not about what its purpose is, whatever it is, can't be working well. If at all.

 

The hose in photo 2 goes to the ADD actuator. On closer inspection it looked a lot better then the photos indicate. All the vacuum tubes system could definitely use a new set of hoses. I don't think its a vacuum leak because if that was the case the problem wouldn't of miraculously fixed itself.

 

I googled this - vacumn hoses and 1994 4 wheel drive 4runner - opened the link in the first group that started with 1995 4runner - may help you? May not? It's worth a shot.

 

Yeah, there are some similarities. Most of the forums cover the 4wd system that come with the auto transmission, so I have to make do.

 

I'm bummed for you.