VC, CDL or bigger issues? (1 Viewer)

[Philis Diller]

Hey all,

I know this has been beat to death but I have a unique aspect to mine that has me scratching my head.

I only got my recently purchased 1994 w/ abs running before Thanksgiving. I bought it non-running for 3.5k. Turns out the PO had installed the distributor wrong as it was off by about 30 degrees. It’s the full time AWD with no lock switches.

It’s not registered yet so I’ve only driven it around the block.

Symptoms:
- it chirps the wheels when making tight turns
- After I turn out of my driveway I noticed it feels like there is a ton of drivetrain resistance when driving in a straight line - almost like the parking brake is on. After driving straight for a bit, the resistance fades out and it finally has a bit more “power” until I turn again then the resistance is back. The resistance seems to be non-existent when reversing.
- after driving 50 feet or so, the ABS light goes on

I assumed it was the viscous coupler so I did the VC test.
- I pulled it into my driveway (had to turn into the driveway beforehand so it had the “resistance” built up from the turn)
- popped it in neutral on the shifter and the H/L selector
- jacked a wheel up - now this is where it gets weird and has me confused. The wheel actually had a LOT of tension built up and as I jacked it up, the wheel started chirping and it spun backwards about 1/3 of a full rotation.
- after the wheel tension had been removed, I confirmed that the wheel does not spin at all.

I know the wheel not spinning points to a bad VC, but the fact the wheel spun backwards and the tension felt while turning/ driving after a turning is odd to me.

It seems almost like my CDL is engaged or engaging even when I’m in High gearing. I’m going to disconnect the driveshafts shafts to check the CDL but don’t have a lot of time right now with other priorities (2yo kiddo and lots of prep for family visiting next week). I am not well versed on 4wd systems but am trying to read more.

Hoping you experts could help point me in the right direction

 

[tmxmotorsports]

Sounds like cdl is on to me.

 

[jonheld]

Either the center diff is locked or the VC is seized.
Considering the history, I would bet on the CDL stuck in the locked position.

 

[Malleus]

The ECM doesn't know if the VC is locked (it's mechanical), but it does know if the CDL is engaged (it's electrical), that's why your ABS light is on - the ECM turned it off.

 

[bubfuji]

Change your T-case oil.
all fuses checked.

Tests:
With the key on, engine off, and windows open. Shift the T-case to Low. You should hear a brief whirring sound. This would be the CDL actuator motor engaging.
Try it a few times. Shifting the t-case to High should also trigger the CD actuator.

If you hear the whirring sound when shifting the t-case to low (CDL motor). Do the diff/abs dash lights come on? (key on engine off)
What was the outcome of the VC test? With the T-case in high. With open diff's, one tire raised. Transmission in neutral, the tire/driveshaft should turn.
You would feel a mild resistance when rotating the wheel. You should be able to do 360 degree turns.
If the wheel will not turn, the VC is frozen.

Other to eliminate:
At the front of your T-case (on top) is the CDL on mechanical switch. Triggers dash lights, Abs light etc. This switch has a two wire connector. If you pull the connector and jump the two wires together. The ABS light and diff light should aluminate with the key on. Run a continuity check on the CDL switch (no continuity with the t-case in high. Yes-continuity with the T-case in low?

Drivers side kick panel, behind the ABS computer. Is the transmission control relay (labeled), also known as the 4x4 relay, or diff control relay). There are three separate relays inside. It is possible one of the relay's inside has gone bad.


94 EWD from the RESOURCES tab