4wd didn't engage

[RICHIET]

I had a problem with 4wd engaging and I didn't find a thread with this angle addressed. Last winter, while on ice, I put the TB in 4 hi,lo, and awd and the dash light showed it was engaged, but I was stuck. My friend said there was no movement of the front wheels. After a push it still didn't engage. I read threads about the front axle disconnect failing, but I am under the impression that when that happens its fried and needs to be replaced or rebuilt. Mine started working again that day and everytime I checked it since. Could this be related to a electrical problem with the rear fuse panel? I have an intermittant problem with the remote entry and the rear wipers not working which I read was related to a grounding problem at the rear hatch. Is it possible that a grounding problem might exist closer to the panel that might affect both problems? I'm speculating at this point since neither problem happened in a while for me to see if they occur at the same time. It might seem far fetched, but I'm just trying to cover all angles since intermittant problems can be a pain to diagnose.

[The Roadie]

Electrical problems of any variety will result in either a) the mode switch having a blinking light over the mode you're trying to change TO, or b) the "Service 4WD" lamp on the gauge cluster lighting up.

Since you didn't report any mode light issues, the problem is almost always a problem in the splined disconnect, for instance the sliding collar fails to slide over the splines it's supposed to, or the fork hangs up due to insufficient grease. That can be intermittent and never happen again, if you're lucky.

You didn't report your mileage, but if it's 50K+, I'd rebuild the disconnect looking for internal wear and properly grease it internally per James' article and inspect the OEM grease for caking or solidification.

[RICHIET]

Thanks. There were no mode light issues and I do have over 120000 miles so an overhaul is probably in order. I was trying to connect dots with this since I didn't get to check it out while it was malfunctioning. It was also 3 degrees at the time so I probably would have been malfunctioning too.

[The Roadie]

If it was 3 degrees, and the disconnect hadn't been warmed up by the oil pan, congealed grease is the most likely explanation. The designers foresaw the issue that if the splines on the left and right sides weren't perfectly lined up when the collar was moved by the fork that was in turn pushed on by the actuator's protruding plunger, that something had to absorb that travel. That thing is a spring inside the actuator's plunger. The actuator's force is stored up in that spring, and as soon as there is a small amount of relative motion between the left and right shafts, the collar is free to move by the fork's force, which has been stored by the plunger. The actuator's motor and gear train have completed their travel, the actuator's position feedback sensor reports success to the TCCM, even though the actual final engagement of the collar might be deferred.

Cold grease can also cause slow/delay movement of the fork or the collar. Better synthetic cold-temp capable grease is the solution.

Just gotta ask because it's my nature: at 120K miles you have changed the transfer case fluid twice and the diffs once each?

[RICHIET]

Actually, I bought the car used with 90K on it because my hondas tranny went for the third time. I did have the fluids changed when I got it.

[RICHIET]

Your probably right about the congealed grease and thanks for your clear explanation on how it works. It's my fault anyway for not putting it in 4wd BEFORE I pulled into the frozen lot and leaving it for a few hours. It's just that I generally get going in 2wd without a problem.

[dirty anton]

also check your tc case control motor. had similar issues last winter. got one off ebay by doorman i think. about 160 dollars. install is maybe 15 mins.

[Badgerfan1181]

Having troubles with my 4wd this is the best place i could find to post this... I tried search

Today i put my TB in 4 hi to get out of a snow bank and it engaged and i drove out but then as i turned " not sharply" it made a loud grinding noise and jerked around it went back into 2wd and was fine but a little worried what it was the transfer case looks normal and both the motors sound like there working fine also 4lo has not ever engaged properly

Any thoughts ?

[Trail X]

As you were turning, I'm guessing you were on dry pavement?

Because the transfer case is a rigid connection between the front and rear drive shafts, if the truck is on dry pavement while turning in 4WD, the system will bind up. You will either scrub a tire, get forcible feedback into the steering wheel, or slip the transfer case clutches.

Standard 4WD 'issue' when used on dry pavement. Here's a specific thread on the subject: viewtopic.php?f=11&t=2310&hilit=binding+4wd

[Badgerfan1181]

That helps with the problem yesterday but have you ever heard of 4lo not engaging ever ?

[navigator]

are you in N rolling forward slowly when you try to engage 4lo like the manual states?

[Trail X]

Ben, why don't you start a new thread on that issue (since it doesn't appear to be a one-post-answer). Post all of your observations with as much detail as possible.

[Badgerfan1181]

Noob mistake my manual says nothing about 4wd except how to change the fluid thanks Navigator, all of my friends 4x4s only have to be in park to engage 4lo

[navigator]

no problem, we were all noobs at some point.

[OregTrailBlazin]

no problem, we were all noobs at some point.

Aint that the truth.. I picked up a Ranger a couple weeks ago, was playing with 4x4 the other day and couldn't get it out of 4low. Took a bit to figure out it won't shift unless your foot is on the brake..