Diagnosing CDL or Viscous Coupler Problem (1 Viewer)

[bulldog1402]

CDL Actuator Problem

I know it has been talked to death but I wanted to clarify something before I get my tools.

Problem:
Pulling into parking space or making a tight turn at slow speeds, my front tires grab/chirp/etc.

From what I have researched, it is either a CDL problem or VC problem.

My truck is a 1994 with no ABS and rear drum brakes. It has a CDL dash switch but does not work at the moment (just got her 3 weeks ago). More on that later.

So I get my jack out, car in N and gear tranny in N, CDL switch off even though that seems negligible. Front right tire in the air and it does not turn.

My question, is my investigation conclusive that I have a VC problem or could it be something else dealing with the issue with my CDL switch?

I plan on diagnosing and fixing the CDL problem first as that is the easier task.

Let me know what you think. Thanks!

 

[KKAAAR]

Experience the same exact thing... It was the viscous coupler

 

[bulldog1402]

Yeah I think it's the same. No way I am paying to put a new one in there either. I just wanted to make sure that my symptoms are indicative of anything else and that my test was conclusive.

 

[bulldog1402]

One last question. With the details I provided, how can I tell if I definitely have the VC in my truck? I know the symptoms are pointing in that direction and it being smoked, but can I tell visually?

 

[bulldog1402]

And here is also where I am at a loss.

Do I have a HF2A or HF2AV?

I know the former has no VC and latter does.

My LC has no ABS and rear drum brakes.

 

[bulldog1402]

I think based on the specs of my truck that I have a HF2A with no VC.

If that is the case, when I raised my front left tire and it did not spin, what could be the cause?

Is it possible my center diff is stuck in the locked position?

 

[Wheelingnoob]

Your truck if equipped with a A442 and 1FZ should gave the viscus coupler.

You can tell by looking at the back of the t case it will have about a 6" extension housing between where the rear drive shaft bolts onto and the main case.

 

[CJF]

Back to your original question: Your test will *not* differentiate between a seized VC and a locked center diff.

 

[OGBeno]

Take a picture of the rear extension housing and that will tell us if you have a VC or not.

Based on what you are saying, you have one of the oddball trucks Toyota made 1993-1995 with rear drums, no ABS, no lockers.

That setup will not have a VC and you will have an HF2A transfer case.

 

[bulldog1402]

Here is a picture. Based on the length...no VC right?

So it would seem my center diff is stuck.

 

[OGBeno]

Definitely no VC.

Could be the CDL position switch.

 

[bulldog1402]

Yeah I haven't been able to find a tool big enough to get it off yet.

I checked all my fuses and kick panel area too where the relay resides.

Well at least no VC shenanigans.

Can anyone identify these empty plugs I found in the kick panel?

This one is right to the left of the dimmer.


These two come from the kick panel. They are attached to nothing.


Finally, right behind the Transmission Relay box there is a green box. Anyone know what that is? What about the splice into the wire in the Transmission Relay?


I am just trying to get to the bottom of this. Every investigation seems to bring up more questions! Hahaha. I like to go through my trucks with a fine tooth comb though so it's all good.

 

[jonheld]

I would start with the simple things first.
Have you checked the fuse for the CDL? It requires power to lock and unlock.
Verify the transfer case is locked or unlocked by removing both driveshafts and grabbing the output flanges with your hands. With the TRANSFER CASE in neutral, the flanges should turn independently.

The CDL actuator can be accessed from the top of the transfer case by lowering the transmission cross member with a floor jack 4-6". This should give you enough clearance to remove the 4 or so bolts.
Once removed, the unit can be tested with a battery. You can also lock/unlock the transfer case manually by simply rotating the gear inside the transfer case.

 

[bulldog1402]

The fuse is good. Visually inspected and tested as well.

Next step I will disconnect the front and rear drive shafts to see if it is locked or unlocked.

I hear the relay clicking when I shift into 4L.

After I do the drive shafts I will check the actuator motor and test with a battery.

I have not driven it at all but took it for a trip around the block today. It still binds up the front when I take tight turns at low speeds.

 

[bulldog1402]

UPDATE

So I did some trouble shooting today. Here is what I came up with.

Fuses good
CDL Switch on dash passed FSM specs
Gauge light in speedo tested ok
Transmission Relay passed FSM specs

I went underneath the LC and found that the CDL plug on top of the TC was unplugged. I cleaned it and plugged it back in and lo and behold the CDL light illuminated on my dash.

Is it that easy??? Unfortunately not.

While the light is now on, it is on all the time. All iterations of 4H, N, 4L and CDL switch and it will not go off. This includes driving around, forward and reverse.

I am not hearing the whirring of the actuator at all. It seems that the electrical system is functioning as it should and the actuator is not working.

I have researched how to take the actuator off but haven't looked yet. Anyone have a good picture of where it is located?

Any other suggestions? It seems to me that the PO could not get the truck out of the locked condition and just unplugged the sensor. This all could be tied together with my front end issue as well.

Thanks and have a great night.

 

[scrowley]

As Jonheld said above you can lower the trans mount about 4-6" to access the actuator. It is located on top of the transfer case. If you go this route take it out and bench test it with a 9V battery. Manually unlock CDL.

Also another option is to pull the plug to the acutator and get some wire with alligator clips. I dont remember the pins to power it forward and reverse but the FSM EWD list them. Lightly tap on the actuator housing while trying to cycle. Fiddling with the input and output flange of the transfer case wouldn't hurt either. Might just be seized up. Just might save the time of taking the unit out. This worked for me . Bought the truck and it didnt work. Did what I listed above and been good every since.

I also took out the CDL indicator switch. Cleaned with electronics cleaner while cycling open and closed a bunch of times. Checked with meter for proper operation. Then re-installed. Easy one bolt removal.

It also might have a broken engagment pin. In that case the actuator has to be pulled and replaced.

Some DIY: http://www.pnwadventures.com/toyota-fj80-landcruiser-cdl-troubleshooting/

 

[Michiana4x4Toyotas]

You are looking at the front drive shaft flandge.....its not fun

 

[Michiana4x4Toyotas]

If you take yours out....take many pics and post...i think i will have to take mine out soon...unlike you though my actuator isnt engaging...thanks!!!

 

[bulldog1402]

Sounds like a good plan for tomorrow.

I need to take off the 4L and CDL lock indicator and clean them as well. Anyone know what size nut is on there?

It annoys me that my car is stuck locked though. Outside of taking a drive shaft off, this will need to be tackled.

 

[yotaslave]

I'm pretty sure the indicator is 24mm. Not a lot of room but it's not on very tight.