24Runna

I've been having this problem for a few weeks now, but it hasn't really bothered me till last night.

What usually happens is it will take many tries of going from H2 - H4 and the engine must be warm. Last night I was at my GF's house, she has a long drive way, the end part in which I was parked has a semi steep incline and since we got ~6" of snow I couldn't get up it, eventually it woke up her mom, and we all shoveled and blowed it. Pretty embarrassing, so I decided to ask my fellow YotaTech'ers, help me! haha. So what do you guys think it might be? Clogged vacuum line maybe?


TIA.




Phil

RobD

When you say you're having a hard time going into 4 wheel drive, is it your transfer case that's not engaging, or is it your front diff? I assume your truck has ADD.

24Runna

I'm not sure to be honest. I hear clicking but thats it, 4WD doesn't engage. Could not enough fluid in the TC cause that? (Doubt it). I will say that I found that my boot on my pass side on my CV has a hole in it because there is grease all over. I have a replacement waiting to be installed.

bigarms23

have your cv boots checked and change the fluid in your transfer cases do you have an auto or manuel. Also make sure you chain didn't brake on the transfer case

mheart624

sounds like you have a microswitch in t-case or ADD going south...need more info...

4Crawler

iTrader: (3)

See the following web page for troubleshooting ideas:
http://toyota.off-road.com/toyota/ar....jsp?id=399612

TomThumb

4Crawler's link has some really good info, I spent a lot of time trying to t shoot issues with my 4x4 in my 91 truck. If you are hearing a click from behind the dash, that is the add relay. That means tcase switch is working, now its just a matter of if it is the vss switches or the actuator on the front of the dif. check to see if there is vacuum going to the vacuum canister on the passenger side behind the bumper. The Vss switches control which line gets suction to the actuator. I think the one closest to driver side is to lock 4x4 and the other is to unlock. Good luck.

24Runna

I do recall hearing a sucking noise, like a vacuum, and I also realized that sometimes RPM's must be high, which leads me to believe that maybe there is a hole or tear in the line? I mean how can it work, but takes awhile?

GSGALLANT

Likely a cracked hose. Just trace back the vacuum lines and look for a disconnected or cracked one. Start under the truck at the front diff, and you will end up at the VSV's on the passenger side of the engine. It isn't a long job to follow those hoses. Good luck.

loudboy

Im having the same issue. When I switch from 2-Hi into 4-Hi, all I get is a little click or two, and the 4WD light switches on for a sec. I've checked my hoses, and I am getting good vacuum to all the right places at all the right times. Is there a way to tell if the front wheels are locking together?(I guess I could but it up on jacks and try to spin one, while watching if the other spins, right?)

Also, I dont hear any noises or ka-thunks out of the transfer case which I would associate with the front drive shaft engaging. After reading all I can on this forum and other, Im guessing I need to check the chain in the transfer case? I saw the chain mentioned a few places, but what is it I am looking for, and how do I get to it? Thanks for the help, soon I hope to return the favor later on down the line!

loudboy

oops, probably wasn't explicit enough.

1995, 3.0 V6, auto tranny

bigtrucknwheels

check your transfer shifter linkage. when I went curb hopping, I broke my linkage free from a pivot point. I could, every once in awhile get the 4wd light on my dash to light, and I'd get the thump, and I'd have 4wd, but most of the time I just heard a solenoid click somewhere, no 4wd light. Put the linkage back on the pivot, and I was golden.

I have the 3.0 V6 and auto as well.

loudboy

I get what you mean by the linkage having separated, but where is that, and how do I get to it? I have the repair manual, but it is at school and I am not, so is it something simple enough, or should I wait until I have the book and pretty lil pictures in front of me? Thanks.

4Crawler

iTrader: (3)

Some pictures of the A/T shifter linkage on the web page below:
http://www.4crawler.com/4x4/ForSale/...tomaticTranny1

loudboy

okay, still poking around both in the engine bay and at the transfer case.

All my exhaust lines are good and getting vacuum at the proper times. If its enough vacuum, I cant say, but it seems to be significant.

My linkage is all good and connected, so I'm guessing my problem is in the transfer case itself?

I've tried spinning the front drive shaft while in 2 wheel drive, but it wont budge. The truck is flat on the ground mind you, not up on blocks where the wheels can move freely; does this matter? I wouldn't think so, since the front diff wouldnt be locked in and the gears at the T-case wouldn't be meshed....am I missing something? Thanks guys!

loudboy

Riddle me this: If a small line is securely tied to the front driveshaft, but the truck is set in 2 wheel drive, the line should not start reeling out and winding around the front driveshaft, yet it does? Why is this?

Heres the story: I decided to do a little experiment. I took some small line (nothing that was going to wreck anything) and tied it to my front driveshaft to see when and if it rotated. At first I tried rolling down the street in Drive and set to 2 wheel drive. Lo and behold, the line starts being pulled from my hand and wrapping around the front drive shaft. Same thing in 4 Hi and 4 Low, though in the 4 wheel positions, I got a few clicks out of the ADD/solenoids , but no engagement of the front diff I dont think. So now I assume that my t-case is stuck in 4 wheel drive all the time, because as I understand it the front drive shaft shouldnt be turning in 2 wheel drive, correct?

lemme know what you think, oh great minds of the yota-verse! Thanks!

4Crawler

iTrader: (3)

Front shaft can turn because the t-case is in 4WD or if the front axle is locked in. One test would be lift the front tires in the air, tranny in gear and see if the wheels can be turned and if the driveshaft can be turned. If you can't turn the shaft by itself, then the t-case is stuck in 4H.

loudboy

I'll work on scrounging up some jacks and get this puppy in the air to figure out which it is - transfer case stuck, or front diff locked up. Thanks for the tip.

loudboy

So I got my truck up on jacks and spun a wheel. Lo and behold, the front drive shaft spins with it. Same with the opposite wheel. So my diff is locked up then, correct? Somehow, its gears are locked in mesh with those coming off the front wheels then. The confusing part is that this only happened in two wheel drive, not in four. So my vacuum lines got switched somewhere along the line. I switched them up, and now my front drive shaft spins freely by hand in two wheel drive, and is locked up to the wheels in four. Great, right? No. Maybe I need to rethink how the gears work, but when I spin one wheel, the drive shaft spins, and the opposite wheel also spins, but in reverse; that isnt right, is it? When being driven around, four wheel drive now actually engages- lights on the dash, T-case shift, front drive shaft spinning and all. Problem here is that my front drive shaft spins while rolling down the street in two wheel drive also. Any idea whats going on here? Am I over-looking something? Over-thinking something? Just plain ol' stupid about something? Any help would be greatly appreciated, thanks all!

4Crawler

iTrader: (3)

Sounds like the front actuator is locked in. Maybe hooked up backwards on the vacuum lines, causing it to be locked in 2WD and try to unlock in 4WD:
http://toyota.off-road.com/toyota/ar....jsp?id=399612