Sunday, January 28, 2018

Front Wheel Bearing

  The wifes BMW had a noise coming from the front end and I suspected it may be a front wheel bearing. Last week I decided it was time to address this issue so I stopped at the parts store and picked up the highest quality bearing they had. Nothing but the best for honeys car. Being a 2011 car most of the bolts came apart quite easily, but when it came time to push the CV axle back out of the hub I ran into some stubbornness. I didn't have the puller I needed and kinda cobbled one together. It was a weak effort at making a puller and after moving the hub about 1/16" out of the bearing, the puller started to bend. This whole time there was some serious noise coming from the other side of the shop. A team of four were trying to remove the fifth wheel plate from a semi tractor and they were having more problems than I was. Pounding, grinding, torching, pounding, cussing, pounding, air hammers...the whole works. I was getting a headache from their noise and my frustration with the wheel bearing and decided to give up for the night. The problem was I needed to put all this crap back together to drive the car home. When I torqued the axle nut back down it wouldn't pull the bearing halves back together. There was now a considerable amount of play in that front wheel. Not dangerous play, but enough that I'd see tire wear if I kept driving it like that. Two days later on Friday I decided to revisit that stubborn bearing.

 The initial disassembly went fast. After all, I already knew which tools to grab and the sequence for disassembly. This time around I had Greg helping me and he came up with some improvements to my home made puller. Crank the puller tight, pound. Crank the puller tight, pound. It came out slow and half the bearing inner race was still on the hub but that would easily be removed with a grinder and a swift blow of a chisel. The remaining bearing would get pushed out in the press, then the new bearing pressed back in. There was a little dinking around but everything went together pretty good.
 Here's the real story. That wheel bearing was never bad. I (and a respected mechanic) heard the noise coming from the left front of the car. Turns out the differential is bolted to the left side of the engine so when its oil level dropped below the differentials output bearing and started making noise, I was fooled into thinking it could be a wheel bearing. Now it clearly also has gear whine that changes as you switch from power to coasting. That noisy session in the shop the first time around eventually revealed the truth. I was turning the wheel hub and could hear that it was noisy but couldn't pin point it. By the time the other half of the shop quieted down enough for me to find the real source of the noise, I had already pulled that hub a bit and started separating the bearing. I would have never done that if I had known there was almost no oil in the front differential. That'll make a noise every time. Kinda odd for a car that was just serviced at the dealership. Yes, I suppose I should have gone through the car better myself.
 I've been in contact with the dealer and although the short term warranty that came with the car is expired, they are willing to take a look at it. I have an appointment scheduled for tomorrow. I'm not sure how this is gonna end but I'll keep you posted.


No comments:

Post a Comment