Don't ignore a dry spindle bushing!

[stlcruiser]

Greetings:

Been having the common symptons of a dry spindle bushing. Intermitant high pitched grinding coming from front end. Would last anywhere from a couple of seconds to up to 10 seconds. Not associated with speed or driving conditions. As weeks went by, it would happen more often. In retrospect, I was lucky that it always happened while driving with no need to brake during each "episode". Two days ago it occured going down hill approaching an intersection. Guess what? No brakes during the grinding. Acted like the ABS engaged and would not allow the vehicle to stop. As soon as the grinding stopped, full brake function! Luckily the grinding stopped just before the intersection.

Got home and opened everything up. Definately a dry bushing and axel. There were tiny flakes of brass in the cavity, but the bushing looked ok. Cleaned everything up, greased the bushing and axel and put it all back together. So far, I have driven 200 miles without any issues.

Question: What would be happening during the grinding that would fool the ABS into engaging on dry pavement? Is this even possible?

Thanks,

Steve
94' 280,000

 

[iptman]

Did you pull the ABS sensor and check for metal debris? The only way the ABS should engage is if those 2 magnets on the sensor don't properly detect the ridges/valleys on the birf ABS ring.

 

[stlcruiser]

I did pull the sensor and saw no metal. Just a few brass dust particles in the bottum of the birf cavity. The loss of brakes happend at the exact time the grinding started and resumed full braking when the grinding stopped. I surmise that the grinding is the axel against the dry bushing. Can this added resistance confuse the ABS into thinking that the wheel is slipping and activate the ABS?

Just thinking outloud.

Thanks,

Steve
94' 280,000

 

[livinoffroad]

Have you checked your calipers? The high pitched grinding could be the metal wear fingers on the brake pads?
Sometimes, heat glaze, or other pad condition problems can cause it.

 

[stlcruiser]

Calipers and pads are in great shape. Grinding was positively spindle bushing related as evident by the cleaning and greasing I did a couple of days ago. Over 300 miles now and no grinding.

Just at a loss as to how I can loose all brakeing during the grinding.

 

[80t0ylc]

Has to be ABS related. IMHO, Only ABS can shut down braking to all wheels. If it happens again, try pulling ABS fuse temporarily to prove ABS is the braking problem. If it is your spindle bushing, it may be vibrating severe enough to cause ABS sensor to malfunction. In any case, I'd be interested in knowing why my spindle bushing went dry. Have you been running in deep water a lot?

 

[stlcruiser]

Spindle bushing went dry due to less than adequate job of reassembly/filling the birf cavity.

 

[BILT4ME]

With a dry spindle, the birf will move around in the cavity (up/down) and may simulate speed loss or changes to the ABS sensor, or even contact with the sensor itself causing failure.

How loose were your wheel bearings as well? It would possibly correlate loose wheel bearings to this condition as well, which would exacerbate the grinding situation. (I always wanted to use exacerbate in a sentence!!!!.....)

 

[stlcruiser]

There was no play in the wheel bearings. I think you are onto something though. I don't quite understand the physics of how a dry spindle causes the birf to move around in the cavity and activate the ABS. If this is the case, it explains everything. If someone can explain this, it would be greatly appreciated.