Ok, so winter is basically over. I just got my truck back from the shop with a freshly rebuilt transmission. I decided to unlock my hubs and stay in 2wd. I go into a parking lot going 2mph and take a left turn. It starts making that clicking/popping noise like 4wd is still engaged. I verify my dash switch is set to 2wd, I jump out and verify that my hubs are in the "auto" position. I think odd...

I start the truck up after running my errand and pull out of my spot and the same noise happens again. I said ok this doesn't make any sense. I then decided to find a snowbank and back into it and get stuck in 2wd. I am in reverse and I try going back, im clearly stuck but I swear I can hear whirring noise from the front diff. I roll down my window and slowly engage the throttle to see if I can look out my front window and see the front tires moving. They are not.

I then decided to get out, lock my hubs but keep the switch in 2wd and repeat by backing up. Same deal, front tires dont move but I swear I hear some whirring from the front transfer case. I then use my dash switch to 4wd. 4x4 light comes on and front tires engage and push me back just fine. I then drive out of the snowbank, put the dash switch in 2wd and take a pretty tight turn (front hubs are still locked). Makes the clicking noise. I jump out put my hubs in "auto" and then repeat the same test... I can still hear the clicking noise..

What the heck is going on?

 

Couple things to try:

1. Confirm the hubs are unlocked from the front driveshaft - can you spin the front drive shafts (I usually grab the U-joints with a long screwdriver) when the wheels are on the ground?
2. Are your U-Joints dry/bad? I have greaseable U-joints on mine and a shot of grease quiets them down a lot - I have had some noticeable pops during a turn with dry joints

 

I decided to scan my truck to provide more information.

Don't mind the other DTC's from the GEM module. They are for rear defrost or heater elements I do not have in my truck (would be an issue if this was an excursion).

 

1. Truck sitting on the ground and hubs set to "auto", selector switch set to 2wd, truck in park or N I can not spin the front driveshaft freely. It spins maybe a quarter turn either way and then feels like its locked.
2. U-joints were done 30k miles ago.

My driveway had some ice on it. I had the hubs in auto and selector on 2wd. Truck would just spin the rear tires. I used the selector switch on dash and set to 4x4, truck drove right out. So it's acting like 2wd to 4wd works as it should.

 

I guess I need to pull my 4x4 hubs out again and look at them. Acting like the hubs aren't disengaging from what I can tell...

Sound about right?

I backed up in 2wd a bit and then drove forward, cranked wheel to the left and right and no longer hear the bind. Hopefully I just needed to unwind the hubs to unlock them by going in reverse. Odd why I am getting those solenoid codes. My 4wd system seems to be functioning as it should.

 

Decided to test my PVH solenoid that controls the hubs.

https://www.autozone.com/electrical-...52297_830050_0

Used the following..

1' piece of wire (qty 2)
aligator clip (2)

I hooked the alligator clip to the center post on the PVH solenoid and then took the other end and hooked it to the negative battery terminal.
I then used a piece of wire from the positive side of the battery and hooked it to the right side of the PVH solenoid using an alligator clip. I could hear the solenoid click
I moved the wire from the right terminal to the left terminal and could hear a click and pressure from the system drop.

Seems as though the solenoid itself works as I hear the click on either terminal. My guess is one side pressurizes the system and the other depressurizes it and the middle is the ground/common.

 

Ok, so I took a big zip tie and wrapped it around the front drive shaft. Theory is the tail of the zip tie will smack the under belly if it's rotating. I got up to 20mph and sure enough I could hear it every 2 seconds. So one of my hubs must still be sticking. I pulled them out last summer and redid them. I guess it's time to switch to warn hubs and get rid of the esof junk.

 

Must be normal operation for front DS to spin a little. I jacked up truck and left passenger side on ground. I could spin drivers side fine. Repeated the same test on opposite side and it spinned freely as well. I think I'm chasing a ghost. More than likely the original noise i was hearing was the hubs and just required me to backup to unwind the hubs.

 

This is interesting, I'll have to compare my trucks operation this week.

I recently switched over to the Warn Hubs and like the easier engagement of them. I also blocked off my knuckles with a NPT plug and capped the lines on the frame. Need to cap near the solenoid though.

 

I can't recall off hand what the recommended interval, but if you haven't put a grease gun on your U-joints in 30k, I'd definitely give that a shot or two. I grease mine every 10k, but I also use my 4wd fairly regularly. Depending on your environmental conditions and use of 4wd, it can't hurt and may help.

For what it's worth, I always back up as well after being in 4wd. Old holdover habit.

 

Front driveshaft shouldnt spin at all in 2wd.. Did they hook up all the elec parts when they reinstalled the trans?

 

Ok, so driveway wasn't melted yet so did this on the side of the street... I am guessing its the driver side hub still engaged? when I spin the drivers side tire the u-joint moves, when I spin passenger side tire u-joint does not move. Odd that when I spin the front driveshaft the passenger side u-joint spins, but the drivers doesn't... To make things even more weird... I can't spin the driveshaft at all when both tires are on the ground... That's what made me believe it was a T-case issue to begin with.

 

Pulled both my locking hubs out and crawled under the truck, I can now spin the driveshaft freely. The u-joints on both sides spin a little when I spin the front driveshaft but I imagine that's somewhat normal due to friction? The passenger side hub is hard to turn. Hopefully that's my culprit. Put the hubs back in and I can now spin the front driveshaft freely even after a drive. So I think the locked hub issue is now fixed, but the weird shimmy is still there. Only other time I have had a shimmy when braking is usually due to brakes... I have power stop rotors and pads on the truck and they have less than 30k miles, seriously hope that's not the issue. Since it only does it when braking, makes the most sense though.

 

When you turn the front driveshaft by hand the u-joints should turn because they are connected to the front driveline. The locking hubs disconnect the wheel hub from the stub shaft on the back side. I can spin just my tires and get no movement of the u-joints but I've heard of people that do get a little movement due to parasitic drag. Since the one side does it and not the other I'd think one of the hubs is sticking a little.

 

Not all U-joints have zerk fittings, if they don't Spicer U-joints should last to 80k miles according to my local driveshaft shop.