Transfer Case not fully disengaging?

Hi Guys,
I just bought a 09 Tacoma 4x4 manual 5 speed Trans. with 161,500 miles.
The truck hasn't been driven much at all for the last 3-4 years the older gentleman that owned it died. The issue I am having is, there is a whining or whurring noise that sounds like its coming from the Transmission or transfer case. It sounds almost like the transfer case is still turning. The dash light 4wheel indicates its not engaged. I didn't hear this noise until I was locking the truck in and out of 4 wheel drive. 4H and 4L.
As soon as I took off down the road I knew something was wrong. Like it was still in 4wd. Is it possible that its stuck in 4H but not turning the front driveshaft?

Also, Now with the truck idling, in neutral I can hear a low whine .
I can push the clutch in and the whine stops. When I drive it on the highway its like the transmission or transfer case gears are whining now. Before everything was quiet.
Is it possible for the transfer case not to fully disengage? Due to one of the actuators not fully extending and retracting ? Do they get sticky if they sit up without use for awhile?

If this helps, I am having issues getting it in and out of 4H and 4L. Sometimes I have to turn off the ignition to get the 4wd to lock and unlock. While turning the knob on the dash I don't hear the actuator clicking as it is being switched about half the time.

My 1989 and 1996 Toyota 4x4 trucks have lock out hubs and transfer case levers . No guessing what's happening with the 4wd.
I am not familiar with electronic shifting functions on the transfer case. I'm assuming something isn't working quite right in the transfer case.

If anyone has had the same problem or any suggestions I would sure appreciate it . thanks guys

 

Nice first post but it’s in the wrong forum. Hopefully it’ll end up in the 2nd Gen forum soon.

In the meantime, searching there will show a ton of info on your problem.

Good Luck.

 

Another question I had was, On this system is it possible that the front wheels are unlocked and the transfer case is still in 4H instead of 2H ? When I turn the steering wheel left and right sharp I don't feel any binding like the wheels are engaged. But it sounds and feels like the transfer case still is. Any help or opinions would be appreciated.

 

It is important that the 4X4 system is used regularly. If not, internal parts don't get lubricated properly and having such issues do happen. Electrical connections can corrode too if they aren't used regularly. I suspect that is the root of the problem since the truck hasn't been driven much lately. And yes, all of what you suggest is possible.

Just guessing, but I'm betting your transfer case is disengaging. My guess is that the hubs aren't unlocking and you are hearing the front axle and diff turning.

Sometimes just getting out on a dirt or gravel road and drive it in 4X4 for an extended time helps. Sometimes the hubs need to be taken apart, cleaned and relubed. And if you have electrical parts failure they may need to be replaced. FWIW, I've seen manual locking hubs fail to work after not being used for an extended time too.

I think the owner's manual suggests 10 miles/month in 4X4 to keep things lubricated. I don't get in 10 miles every month, and I may skip a month occasionally. But most months I'll get in at least a couple of miles and depending on the time of the year some months may see 200 miles in 4X4. I think the key is to use it regularly to prevent these problems.

It is best to shift from 2wd to 4hi while moving. If you're at a dead stop the gears in the transfer case may not be aligned so they will engage. Just letting the wheels roll a partial turn will let everything line up to engage. It is best to go back to 2wd from 4hi the same way.

Getting into 4lo can be tricky with ANY 4x4 vehicle. Technically you should be able to go straight from 2wd to 4lo. But I have fewer issues going to 4hi first. Then stop, shift to neutral, OR in your case press the clutch all the way down. It is important that it be ALL the way down before making the shift to 4lo. Once again if the gears aren't aligned it helps to let the vehicle roll slightly (under 2-3 mph) for them to engage.

Getting out of lo range can be the hardest. Sometimes the gears bind and don't want to let go. Driving for 10-15' in reverse while in 4 lo, then pulling forward 10-15' helps release the binding. I've had to do that little dance several times in the past to get the gears to disengage. And this isn't just Toyota specific. It happens with all 4X4's.

 

Thanks Marshall,
I'm assuming on this system if the hubs are not unlocking the front driveshaft will not spin freely? I think what little the truck was driven before I bought it the 4wd was never used. I would guess the old gentleman that passed never used the 4wd much if any.
If the hubs are unlocking where would be the next place to look?
When I drive it do the road now something is diffently turning that's not supposed to be. Its almost like a drag on the truck like when its in 4wd.
I had one of my old trucks lock out hub fail on me once. I hadn't used it in about 2 years. Front end was only locking on one side. Took the hub off, grease had gummed up and wouldnt release the gear. This is the first 4wd I've owned out of about 20 that didn't lock manually. I guess I'm old School ,used to the old way, get out lock the hubs and shift the transfer case manually..
I was an Electronic engineer for 30 years.
We had an old saying, The more electronics you pile on a device the more failure prone it is. I was always an advocate of KISS.

Yesterday I guess one thing wrong I was doing was, I only moved the truck back and fouth a foot or so trying to lock and unlock the 4wd

 

Me thinks your throw out bearing is starting to go... That it whines in neutral fairly eliminates rotating considerations from the diff/axles/hubs/ That the noise goes away as you apply the clutch is a classic throw out bearing symptom.

 

MR5X5,
Thanks for the reply, If the throw out bearing is going, will the whine get louder while shifting gears driving down the road? All the throw out bearings I've had in the past only made noise when I press in the clutch. On this truck is the throw out bearing riding on the fingers of the pressure plate?.

 

In my experience, not with any tacos mind you, it has always been the "unloaded" bearing rattling on the pilot shaft indicating it was on it's way. I presume the taco clutch system works the same way. If not, sorry for the misdirection...
As far as the whine getting louder, hard to say, different harmonics and such. Not believing to much in coincidences I'm inclined to think your whine at neutral is your whine at speed. That it whines neutral really limits the amount of rotating parts that could be suspect.

 

If the front driveshaft is not spinning, then the front end 4WD is working correctly. You don’t have locking hubs like older 4WD systems. What you have is a sliding collar in the axle tube that locks in passenger side front axle via a splined shaft. The front axle uses an electric motor to slide the collar back and forth and it engages only after the transfer case is in 4WD so that the splines engage. The front diff spiders spin as the driver’s side axle is attached to the differential. The transfer case also has an electric motor that moves a shift rod to mechanically engage the transfer case. First place to check is fluid levels in the transmission, transfer case and front diff. From what I understand, but I may be wrong, the throw out bearing always has a slight bit of preload and will spin without clutch engagement. There’s been a bit of debate on this so I could (probably am with my luck) incorrect.

 

Thank for the info guys, I think we're getting somewhere now, after reading the post I went to check a few components. As for the throw out bearing. With the truck idling , clutch out, I took my mechanic s stethoscope and probed around on the bellhousing, transmission and transfer case. Everything sounded pretty good until I probed the throw out bearing lever. When I probed the lever it was very loud . Almost like a squeaky roar. Of course you don't hear that much detail with your ears alone. I pushed in on the slave cylinder and the noise Subsided to about half. But still loud. Is the throw out bearing supposed to be running on the pressure plate all the time while driving ? And will it be louder while going thru the gears causing the whining I'm hearing now. I've never had a throw out bearing that worked like this one. The ones I had sit idle until you push in the clutch. Is there an adjustment that cures this preload problem? It would seem if the throw out bearing rides on the pressure plate fingers all the time it'll wear out in no time.


I also checked my front driveshaft, it does spin freely on 2H. But when I try to spin the axles while in 2H they will not spin at all. Are the hubs locked I as Marshall indicated? Are they supposed to spin freely in 2H ? Also, I checked all the levels in transmission, transfer case and diff. All were full.

 

Axle shafts will not spin freely with the front tires on the ground. The axles are splined to the front bearing hubs and held in place with a nut like front wheel drive cars.

 

Ok thanks , That part is working.

 

Here's how 4wd the system functions. The CV shafts are splined directly to the hubs so there are no "locking hubs" and the CV shafts and their corresponding wheel will always rotate as one. There is a disconnect on the front axle, the ADD (automatic disconnecting differential), which uses a collar to disconnect the passenger side CV axle from the differential. Lastly, there is a shift collar in the transfer case that engages and disengages the chain for the 4wd front output.

Functionally, both disconnects must operate for the front driveshaft to not spin in 2wd. If you can spin the front driveshaft freely with the truck on the ground, both disconnects are working.

From the description of your noise I agree with throw out bearing. I had the 6 speed in my '05 x-runner with the throw out bearing squeak for many tens of thousands of miles. It was known as an annoyance, not an impending failure. URD had the best fix that I know of. Would've done it if I kept it until it needed a clutch.

 

Thank you ShimStack for the help and explanation. Did your truck whine thru the gears while driving too?

 

I really only noticed it at idle and especially in a drive thru. But it was loud. More of a squeak than a whine though.