Front End Binding & Clunking When Turning

Hello. Yesterday I replaced the front left hub assembly on my 2003 Explorer due to a bad bearing. I thought maybe the bad bearing was also the cause of the clunking and binding coming from the front end. Wrong. After replacing the hub assembly it's still doing it. It appears to be fine when driving straight. It only does the clunking and binding thing when making a slow turn. In drive and reverse. Also, the 4X4 High light will flash off and on maybe 8 times then go off. I'm not sure what to check first. The boot on the CV joint looked good, no cracks, but is it possible the joint is still bad? How can I check it? Or am I looking at something more serious? This is a V-8 with Auto. 4X4 with 91K miles. Any input would be greatly appreciated. About 3 weeks ago I changed the fluid in the rear differential. I used Royal Purple and the Motorcraft friction modifier. I have a 45 axle code.

my first guess would be the transfer case, it is common on the awd models for the viscus coupler to fail.

Unless your truck is stuck in 4hi for some reason, replace your outer CV joint. These joints can be pretty weak at full lock. I've had a couple let me down out in the woods with an old S-10 Blazer. Just because the boot isn't shot doesn't mean the joint isn't.

Just realized I have an open differential. I hope adding the friction modifier doesn't cause a problem. Should I drain the rear differential?

Thanks for the quick responses. Does the Auto. 4X4 Explorer have the viscus coupler? Or is that just in the AWD Explorers? What is the best way to check the CV joint? Who makes the best aftermarket replacement? It sure sounds and feels like the left front but I could be wrong. After work today I'm gonna do another inspection of the front end. I just hope I'm not looking at a transfer case or front differential problem. This my first Explorer so this is all new to me. This website has already been a big help. Thanks again.

rankins66 said:

Hello. Yesterday I replaced the front left hub assembly on my 2003 Explorer due to a bad bearing. I thought maybe the bad bearing was also the cause of the clunking and binding coming from the front end. Wrong. After replacing the hub assembly it's still doing it. It appears to be fine when driving straight. It only does the clunking and binding thing when making a slow turn. In drive and reverse. Also, the 4X4 High light will flash off and on maybe 8 times then go off. I'm not sure what to check first. The boot on the CV joint looked good, no cracks, but is it possible the joint is still bad? How can I check it? Or am I looking at something more serious? This is a V-8 with Auto. 4X4 with 91K miles. Any input would be greatly appreciated. About 3 weeks ago I changed the fluid in the rear differential. I used Royal Purple and the Motorcraft friction modifier. I have a 45 axle code.

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Just something to rule out here, but I doubt this is your problem since your 4x4 high light is flashing. I had a clunking noise on my Ex a while back when making slow turns. It turned out to be a "loose locking nut" on a tie rod end. Once tightened up, clunking noise stopped. It's simple to check, you probably know that. Are all 4 of your tires the same size and tread wear? Different size tires can cause the auto 4x4 to kick in. My auto 4x4 kicked in a few times on me from a little wheel slippage when making a sharp turn from a dead stop and giving it some gas to get up to speed. Kind of sounded like a clunking noise.

Axle code 45 is 3.55 open diff, no limited slip so I don't think friction modifier is needed

Sure sounds like a transfer case (center differential) stuck in 4WD.

After work I jacked both front wheels up off the ground, turned the steering wheel all the way to the right, and spun both wheels by hand. No sounds coming from the CV joints. I unplugged a main harness (large black plug) at the rear of the transfer case. I drove the Explorer around the parking lot and no more clunking sounds. So, do I have a transfer case problem? Will it hurt anything to drive it like this until I can get it fixed? After I drove it, I did notice the cover on the front differential was pretty wet. I haven't noticed any drips though. 4X4 High light is still flashing 8 or 9 times even with the harness unplugged.

Plug it back in and see if it still binds the drivetrain while turning on dry pavement. If so, you have the culprit. The center differential. Yes, driving on pavement with a locked center differential could cause further drivetrain damage. It also causes vehicle insability and could cause an accident. 4x4 light is indicating a diagnostic code that is stored. No doubt unplugging the TC harness has also stored many more codes but this will be easy to sort through with the proper code reader.


P.S. "Go Bucks"

Thanks. I'll plug it back in after work today and go for a test drive. I have a friend with a Snap On code reader. I'll have him check the codes. I wonder what the chancs are of the problem being the switches on the dash that control the 4 wheel drive or something else electrical.

I plugged the transfer case/motor back in tonight. Same as before. Something in the auto. 4X4 is causing the front differential to engage. It shifts in and out of 4 low just fine. Could it be the control module for the 4 wheel drive? I guess I'll know more Thursday night when we hook the scanner up to it.

I took the Explorer to have it scanned for codes and the guy told me to replace the rear abs sensor first because the light was on. His scanner showed it was the rear abs sensor. Sorry I didn't mention this before. The abs light was on when I bought it so I didn't think too much about it. He thought maybe the bad sensor could be causing the auto 4x4 to engage the front differential. I replaced the sensor, the abs light turned off. I plugged the transfer case/motor back in but it still stays in 4x4 high after pushing the auto. 4x4 button the dash. As I said before, it will go into 4x4 low and back to 4x4 high just fine, but when I push the 4x4 auto. button it goes into 4x4 high. I pulled the shift motor off last night to look for a broken ground wire or anything else obvious but I didn't see anything. 4x4 high light is still flashing. I unplugged the transfer case/motor until I can take it back again to scan for codes.

The ABS was a good place to start. It looks at multiple places to decide if it needs to engage the front output shaft. Your V8 has a viscous center differential rather than a true transfer case but their function is very similar. The way they go about achieving this function is very different. You really need the codes to determine why it thinks it needs to engage the front output.

Turns out it was an output shaft speed sensor in the transfer case. I assume it was the front sensor but I replaced both front and rear sensors. $135 later, problem solved. Does anyone know how to check the oss sensors out of the vehicle? Thanks again for everyones help.

Do you have the part numbers for the two speed sensors that you replaced?