Jeep's unit bearings are not created equal. I have taken apart many coiled front front axles for the various parts that swapped between them. Or at least I presumed.
After a trail ride to Clayton, my passenger unit bearing decided to show its wearing signs. I swapped it out once I got home with one I had on the shelf.
Well, the one on the shelf is ~1/4" too short in distance between the mounting surfaces of the bearing. The eccentric center also has a raised lip on it.
When swapping it on, mounting to the knuckle was no problem. The axle stub was no problem. Mounting the rotor no problem. Didn't realize the rotor was held against the raised lip on the center flange with a 1/4" gap. Put wheel spacer on no problem. Assembled caliper on the knuckle, aligned with rotor, no problem. Mounted wheel, no problem. Everything appeared to be tight.
Drove here/there (1-2 times), no problem. Then driving for 45 min, the front tire started to wobble. I figured my spacer nuts were getting loose as the wheel lugs were tight. Once I took everything apart, found a unit bearing stud pulled out and all the nuts loose on the spacer. Typical I anticipated as I didn't use locktite on the spacer lugs. Reassemble and got everything tight. Couldn't get the caliper on and to align with the rotor. Couldn't rotate the rotor as it was up against the knuckle.
Took a while, but finally figured out the mounting surface difference was putting the rotor against the knuckle. Swapped in another used one and I'm all better.
Pics. To add, the lugs on the wrong unit bearing are longer as well.
What had happened, I didn't get the rotor on correctly, so the spacer wasn't installed correctly. With the push/pull of the wheel while rotating/turning, it put torque-arm pressure on the spacer nuts. In time, they rotated loose and the rotor moved over the flange lip, giving more movement and torque-arm pressure. I did mess the rotor up some with the center and lug holes, but its reusable.
The measurement for the correct unit bearing mounting surface distance between the wheel and knuckle is 2-1/8". The shorter unit bearing is 1-7/8".
After a trail ride to Clayton, my passenger unit bearing decided to show its wearing signs. I swapped it out once I got home with one I had on the shelf.
Well, the one on the shelf is ~1/4" too short in distance between the mounting surfaces of the bearing. The eccentric center also has a raised lip on it.
When swapping it on, mounting to the knuckle was no problem. The axle stub was no problem. Mounting the rotor no problem. Didn't realize the rotor was held against the raised lip on the center flange with a 1/4" gap. Put wheel spacer on no problem. Assembled caliper on the knuckle, aligned with rotor, no problem. Mounted wheel, no problem. Everything appeared to be tight.
Drove here/there (1-2 times), no problem. Then driving for 45 min, the front tire started to wobble. I figured my spacer nuts were getting loose as the wheel lugs were tight. Once I took everything apart, found a unit bearing stud pulled out and all the nuts loose on the spacer. Typical I anticipated as I didn't use locktite on the spacer lugs. Reassemble and got everything tight. Couldn't get the caliper on and to align with the rotor. Couldn't rotate the rotor as it was up against the knuckle.
Took a while, but finally figured out the mounting surface difference was putting the rotor against the knuckle. Swapped in another used one and I'm all better.
Pics. To add, the lugs on the wrong unit bearing are longer as well.
What had happened, I didn't get the rotor on correctly, so the spacer wasn't installed correctly. With the push/pull of the wheel while rotating/turning, it put torque-arm pressure on the spacer nuts. In time, they rotated loose and the rotor moved over the flange lip, giving more movement and torque-arm pressure. I did mess the rotor up some with the center and lug holes, but its reusable.
The measurement for the correct unit bearing mounting surface distance between the wheel and knuckle is 2-1/8". The shorter unit bearing is 1-7/8".
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