4WD, ABS, BRAKE, TIRE (Solved)

[blktoptrvl]

This is an extension of a post I added to another thread. I am putting it here because I was getting no traction on the other thread, and because I think my problem is different from what I first assumed.

I was coming into a shopping center and as I slowed I thought I heard a uncharacteristic whine from the transmission. I completed my shopping and then came out to the car (2006, 4.4i), as I started driving, I thought I heard a grinding or bad bearing noise coming from the underside. When I got home, I put away the groceries and took another short drive, This time I could not be sure if I heard the noise or not (if it was there, it was very faint).

Two days later, I get all the four lights mentioned in the title. When the lights come on, the car seems to drive smoother than when I hear/feel the slight grinding. I figured I probably had the trifecta problem and that the extra light was some kind of bonus. When shutting down the car, I never heard the clicking noise, but then I also read that that was not always present when the TCA gear is giving trouble.

Anyway, I removed the TCA, stripped it down* and found that there was very little wear on the gear (picture), certainly not enough to proclaim this as the problem.

So, today, I will put the TCA back in place with the new gear and go from there.

1. Has anyone have any experience with all four lights mentioned?
2. Does anyone have any advice as to where to look next in case the slight wear on the gear was not the problem?
3. While the TCA is out, is there a way to do any test of the transfer case?
4. Is there a test that can be performed on the sensor removed at he second wire harness connector?

After more investigation, it seems I should be looking at brake sensors. Any input would be appreciated.

*BTW, if you are trying to get the plate off, I fought with it for a long time, then put it into my oven for 15 minutes at 200 degrees - it then popped right off. Nothing seems to have suffered from the heat.

[blktoptrvl]

Tried to see if the shaft of the TC - on which the actuator mounts - could be turned by hand. There was no movement.

Next I am looking for a way to bench test the TCA to see if it is even running when commanded.

[Ven]

Exactly same problem on my e83 which uses a lighter variant (atc400) of the facelifted e53 t-case (atc500). My mechanic and I are out of ideas. My gear was almost not worn but got triad.

Not sure how you'd bench test the tca? I am tempted to buy a rebuilt tca with 1 yr warranty from eBay but on the fence.

[richardb]

I remember doing this recently, for us it was just the gear. Here's the DIY I did for those searching and landing on this page:

https://youtu.be/UR7Vv5SQvDc

[blktoptrvl]

I put the TCA back in. It was amazing how fast that was.

It took me about 45 minutes to get the TCA out, and just 5 to get it back in. At first I thought I was having a problem with dexterity while getting it out. The real culprit was that I just had a hard time getting the E10 and ratchet wrench onto the torx head.

Before putting the TCA back in, I stopped by Harbor Freight and purchased a stubby 8mm combination wrench - that made it much easier to get the 4 bolts back in.

Like wise, if you have trouble finding a female torx for the small bolt holding the sensor, a 3/16" socket will do the job.

I still have a question as to whether a test is available for the TCA and also for the sensor at the end of the wire.

-------

As a note to myself and also to anyone else who does this, I need to break my habit of carrying tools, parts, or hardware around the house as I am doing jobs, I spend more time looking for these items after I set them down somewhere than I do getting them back on the vehicle.

[blktoptrvl]

137K Miles. Took it out today and made the following observations...

• There is definitely a Grinding/Crunching noise when the vehicle first starts moving. This is not a gear griding noise, but more like a bearing grinding.
• There is a dragging feel - just as you would get from a FT 4WD system when turning.
• After the car has been moving for a while the noise starts to fade.
• It is not until 40MPH that the car will start throwing lights.
• There are no ODBC codes stored.
• The problem is definitively in the fwd section.
• After the lights come on there is no noise at all and the dragging goes away. This makes me think it is not a front shaft/bearing problem.

More and more, I get the feeling I will have to remove the transfer case. Before I do that I still think I should test the ABS sensors.

[blktoptrvl]

Lifted the car today, spun the front wheels and found nothing. I guess I was hoping that I would hear or feel some binding or any other problems with the front wheel drive.

• I tried this with both wheels in the air with the car in neutral.
• I tried this with both wheels in the air with the car in drive (not running).
• I tried this with both wheels in the air and one wheel blocked while spinning the other. For each wheel, it sounded normal.

I then noticed that the plastic box that holds the connectors for the ABS(?) and the Bark liner sensors was open and one of the sensors hanging with the wires appearing to be stretched.

I will remove and continuity test each of the wires. Does anyone understand the pin connections for these wires and to where they are routed?

[blktoptrvl]

So...

The hanging wires do not seem to be an issue.

I removed the front left wheel and rotated the disk rotor back and forth. I could hear a pretty significant amount of play in the shaft. It is not terrible, but enough noise to indicate the shaft needs attention.

Looking around I do not see any driveshafts for much less than $250.

2006 BMW X5 Drive Shaft - BMW X5 Driveline - Free Shipping

The page does not indicate if this shaft is for a 3.0 or a 4.4i. Are they different shafts? Can a shaft be rebuilt? Edit: I called them, the Driveshaft on the 2006 is the same on the 3.0 and the 4.4.

They also told me that the Transmission/Transfer case apparently store codes. So, Since I am pretty sure the driveshaft is bad, I took it to a shop to get the codes read, and the diagnosis.

On the way to the shop, the noise was horrible - until the car kicked it out of 4wd - which make me think it really is a shaft problem. I was tempted to just go back home and order a new shaft, but I might as well get the codes read.

Question...

What is it I am reading about extended shafts - why are some of you folks buying them?

[blktoptrvl]

Shop called...

They said they could not/would not drive the vehicle to listen for the noise I am hearing because the left rear bearing is in bad shape and they didn't feel it was safe to drive.

Now, I have been driving the car pretty hard and didn't feel any problems from that area. So, I jumped into my other car and flew over there to see this wobbling wheel for myself.

Sure enough, the left rear was making noise when you tugged on the wheel. I am flabbergasted. I am also hoping the wheel bearing is my only problem - and at this time, that is really only a hope! What I do have in my favor is that the mechanic says that the codes are reading as ABS and that there is an indication of a "air gap" being too big? (hopefully that means that the bad bearing was allowing the hub to move too far from the abs sensor (again with the hope!)

I told them to go ahead and replace the bearing as I do not have any pullers at home and because if this is still not the problem I will need further diagnostics.

[blktoptrvl]

Here is the final Disposition.

The four lights (all yellow):

• Tire
• 4x4
• Brake
• ABS

Indicate there is an ABS problem. And in particular (in my case) that there is a unreliable read at the ABS sensor. The "Air Gap" code in my case also indicated that the bearing was bad and that the sensor couldn't maintain the communication with the hub ring.

Lessons Learned:

• I shouldn't have assumed that the "Trifecta" lights problem applied - obviously it didn't.
• The codes are in fact stored in the OBD2 computer. However, my reader could not get them all. I need a better reader.
• Don't believe everything you hear coming from the underside. I thought I hear the bearing noise coming from the front of the car, it was coming from the back. Had I continued on the path I was following, I would have had the front drive line disassembled by not and would have been no closer to solving the problem.
• Sometimes, you should just punt when you are not sure and get a professional diagnosis. (My thanks to Brown Motor Works in Columbia, SC, of course I am not thrilled to have spent the dough, but it is probably less than I might have ended up paying if I had continued.)
• Now I have to research the difficulty of doing the other bearing.