[pickwick]

I finished my last track day with wheel bearing noise during right turns. But I can't tell if it's front or rear. I jacked up the left side of the car last night but couldn't tell from turning the wheels which was noisy.



Car has 90,000 miles and has seen 30+ track days. I replaced the front bearings about four months ago; the rears are original as far as I know. There's some chance my non-OEM bearings didn't last, and some chance that I didn't pack them properly, or used grease that didn't hold up. Doing a little swerve to the right--not even enough to change lanes--makes the noise about twice as loud. Swerving back left it almost goes away.



Short of tearing into to the fronts again, how can I be sure which end is the problem? (The fronts I'd redo myself, the rears I'd take to a shop.)

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[Jason Judd]

The only thing I can say is that the rear bearings cost much less than the fronts...



You might just replace the rears (I did at about the same mileage) and see how things go.



Jason

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[ds968]

Jason ,



??? Do you mean just the part itself ?



The work associated with the rear bearing replacement requires about 2 to 3 times the length of time vs. the front, so if a mechanic does the job for you

it's the rear bearings that are more expensive.



I'm pretty sure that's the case anyway..

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[Jim Child]

Your swerving comment makes me think its the front, so I'd definitely check it out. However, given that this is the off season, and your rears are original with 30+ track days, it would be a good idea to take care of those as well. If you have the rears done make sure you use new axel nuts and have them properly torqued down. They take something like 368 ft/lbs. If you use old nuts or don't torque them down properly, the driver's side nut will begin to back off, something you don't want to have happen on the track (ask me how I know).

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[flash]

huh? jason, you sure about that?



when we did ron's, the fronts were cheap, was a standard job, and simple - i'm thinking it was like 50 bucks for the inner and outer, and took me a half hour - recently, on another local car here, the rear was nutty, somewhere around 100, and required either removal of the control arm, or a bearing press - that job got sent out and was a bit over 400

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[Jason Judd]

Yikes,



Maybe I got the front and rears mixed up...sorry!



Jason

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[flash]

no worries - just wondering if maybe i missed a cheaper source for the rear bearing or something - i'd have to ask ron agian what he paid for the fronts, but i seem to remember they weren't really out of line of any other such bearing

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[ds968]

my repair job a couple of months back : the rear bearing was $ 82 ( one ) and added to that were 4 hrs of labor ( $90 / hr).

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[orphanowner]

I used to do rear wheel bearing REGULARLY on my 944T racecar. The combination of Willow Springs being primarily high speed right turns, 400 rwhp, and 12" tires did the left rear bearing in quickly. Buttonwillow and Laguna were pretty hard on bearings too. Don't even get me started on front wheel bearing/hub failures...



I ended up with the Baum bearing press so I could do the repair in the field. Here's a pic of some carnage when the hub nut backed off during a POC enduro at Willow Springs. Good thing the rotor kept the hub on the car.



I used to see aluminium shavings peel out of the control arm whenever I pressed in a new bearing. Even freezing the bearing and heating the arm didn't help much. I was only reusing control arms twice. Any more than that, when the brakes got hot I could feel the bearing walk in the housing by the extended brake pedal travel. The late 968 control arms have a revised and improved retention method that uses a bolted cover rather than a snap ring. 968= best of breed.



I was getting FAG bearings wholesale for around $35 each and used to use the same 300 ft lbs torque wrench my Cup Car buddies used on their spline lock wheel nut to tighten the hub nut.



Now back to my cocktail...

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[jgporsche]

I used this tool off of eBay. Worked on my 88 911 rear wheel bearing, which I think, is very similar to a 944/968. I also bought the 968 flywheel lock from this vendor and both worked great. No, I'm not affiliated with this vendor but it works.



http://cgi.ebay.com/ebaymotors/Porsche944-...itemZ4580877365



I believe eBay also had OEM rear wheel bearings for $80, which was for two of them. I changed both bearings, but heard that one of the rear wheel bearings goes out more often than the other due to tracking. This is definitely DIY if you use a press or a specialized tool. I tried the large Harbor Freight wheel bearing puller and it just shattered.

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[pickwick]

   

I finally got around to pulling the front wheels. Here are the outer bearings, after only 1900 street miles and 200 track miles. The left race has the matching three visible lines, although I can't feel them. The right race has a matching discolored area. Both feel smooth and aren't pitted. But since I can't inspect the inners without removing (and possibly damaging) them, and I'm halfway there, and the parts are only $50, I guess I'll replace them.

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[Greimann]

What kind of grease are you using on the wheelbearings? That duty cycle is kind of short. <img src="/forum/images/smilies/968/sad.gif" class="smilie" alt="" />

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[pickwick]

[quote name='Greimann' date='Dec 18 2005, 06:04 PM']What kind of grease are you using on the wheelbearings? That duty cycle is kind of short.  <img src="/forum/images/smilies/968/sad.gif" class="smilie" alt="" />

[right][post="13510"]<{POST_SNAPBACK}>[/post][/right][/quote]



It was Valvoline "Val Plex EP"; nothing fancy, just something I had on the shelf. The container did mention wheel bearings but I'm not sure it was the best choice.



Still not sure either bearing was the noisy one; they just don't look very good for as new as they are. My plan is to pack the new ones with Redline CV, unless you have another suggestion.

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[Greimann]

The Val-Plex is definitely a middle of the road grease. Nothing special. The Redline CV looks to be much better by the online data sheet, but they mention an organic red moly in their formula. The only true molydisulfide I know of is black, and any grease formulated with genuine moly is black or dark green.



I have a sample of some special high performance moly grease that is not available to the open market that I use in my wheel bearings. Contact me offline if you want a sample of this stuff, otherwise, I would look for a high temperature wheel bearing grease that contains moly and is black in color.

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[flash]

man, if that's the same stuff you gave me, i love that stuff - nasty to clean up - can't get it off of anything - but then, that's probably what makes it so good

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