Wheel bearings?

carnut169 · carnut169's Garage

Noticed a slight (very very slight) vibration being transmitted through the steering wheel. Could be the new Kuhmos, but I noticed that when turning left (just enough to take the pressure off) the vibration will go away. My experience with other cars is that this is a sign that the wheel bearing are going bad- does that sound right on this car? I checked Pelican's site for the wheel bearings and it looks like Wayne only carries them for a 912.... what gives? Any other way to determine if they need to be replaced? How hard a job is it?

Early_S_Man · 06-12-2002, 06:15 AM

Sean,

The only way I know is to remove, clean & inspect them ... getting the dust cap off is often the difficult part!

All '65-'89 911's & 912's use the same wheel bearings and grease seal as the '64-'65 356C/SC.

warment · 06-12-2002, 06:25 AM

Replacement is a snap. If I were you, I would buy a "bearing packer", some fresh grease and "repack" each bearing. I ordered my bearing packer from JC Whitney and it worked great...

Bill

Jdub · 06-12-2002, 06:30 AM

Dumb question: how does a bearing packer work and is it really that much better than the traditional hand-packing method?

Thanks,
John

DavidPorter · 06-12-2002, 06:51 AM

The one I bought a few years ago has two white plastic cones threaded on a central metal piece with a grease nipple at one end. You put the bearing between the cones and use a grease gun to inject the grease. My trouble is I never seem to have a grease gun full of wheel-bearing grease handy and so I've never used it. I don't think the packer does a better job than hand-packing, but it would save time and clean-up.

rickeolis · 06-12-2002, 06:52 AM

The bearing packer uses blocking plates that only allow forced grease to pass through the bearings; very effective.

The hand method only works when applied correctly, if 1/5th of the bearing does not get gease, it could fail.

You want the grease inside the bearing roller parts, not just visually outside. Either method also requires a cleaned bearing set first.

juanbenae · juanbenae's Garage

DP said "nipple" .... hehehehe

DavidPorter · 06-12-2002, 07:08 AM

People don't call them that any more?

Now that I think about it, I guess the Gen-Xers out there (and Y, and Z) have probably never seen a car with a grease nipple. My lawn tractor has several, and it has required zero maintenance other than oil & grease for 15 years. That's why I don't have my grease gun filled with wheel-bearing grease.

Superman · 06-12-2002, 07:40 AM

Wheel bearing problems usually make a terrific amount of noise. They roar/rumble. Check to see if the wheel is loose. Of course, inspecting and repacking bearings is never a bad idea. They can be packed effectively by hand, but it takes much longer. Bearing packers are VERY effective at loading bearings with grease.

If you do change bearings, be very very careful removing and replacing the races. There have been threads warning that these aluminum hubs are easy to damage, and I believe that. Be extremely careful. The correct procedure would involve heating the hub, and using a press to move the races. Since most of us do not have presses, extraordinary care is called for.

Zeke · 06-12-2002, 08:05 AM

I am always suspicious of the last change to the car when tracing problems. In your case, you seem to have just installed new tires when you noticed the problem. I think it's the tire. How's the runout on the left front?

Jdub · 06-12-2002, 08:22 AM

Thanks very much guys. I can picture how this works now. Never thought I saw the nipple on the halves and so wondered how the grease got the heck in there. I have always packed by hand but will be purchasing this tool in the future.

I also agree that the new tires could have natural unbalance to the tire itself. Often you must reseat the tire on the rim to get the balance right. That is, the heavy section of the wheel is set exactly opposite of the heavy section of the tire. You might have the front wheels rebalanced, carefully choosing the mechanic who does this and being sure to let them know what your expectation is. Pizza helps.

John

carnut169 · carnut169's Garage

I agree- it may be the tires, but I have another possible cause. Did an oil change last night, and when the car was on the lift I noticed a bunch of grease on the inside of my left rear wheel... cause is a busted cv boot. Can the be felt? How do you guys rate the ease of this repair? I know there are some issues with the special bolts and a tool is required. I can have it done for $450 (all four boots) does it make more sense to just have it done (the mechanic will let me hang with him and learn at the same time) or to give it a go myself?
On another note- the Kuhmos balanced perfectly. No weight on the front wheels which I have never seen before. The shop said it was not common, but the computer tells them exactly where to mount the tire on the wheel so it does happen.
Thanks for your input!

Superman · 06-13-2002, 07:36 AM

Including parts, I consider CV boot replacement (4) to be no more than a $200 job, including disassebling cleaning reassembling. I'd strongly suggest you do this yourself. It helps a great deal if you have a bench vise. Also, go to your local used book store and see if there are any old Bentley manuals. Like for VWs or something. Those older Bentleys had a beautiful section on disassembling and reassembling CV joints. CV joints are pretty much all the same. Designed, like everything else on automobiles these days, by the Germans.

Early_S_Man · 06-13-2002, 08:21 AM

Sean,

You can remove, disassemble, clean inspect the CV-joints with hand tools ... and any without significant damage to the ball bearings or races can be repacked with a high quality moly grease such as Valvoline #986 SynPower Synthetic Grease, which is rated for use to 420° F and meets or exceeds all US, Japanese, and European mfr specs for CV-joints!

The following thread has four scans of an earlier VW manual by Bentley showing servicing of the Lobro CV-joints:

CV joint disassembly

Here is a site with very good pics and discussion of Lobro CV-joint servicing ... that happen to be about VW air-cooled Type 2 buses, but the info is valid for 911's as well:

http://www.type2.com/bartnik/cvjoints.htm

ChrisBennet · ChrisBennet's Garage

Starting in mid 1985, the axle changed. The out CV joint's stub axle is "friction welded" to the something or other now and you can't just unbolt the outer CV joint and repack it. I sawed one of mine open and put it back together with aluminum (metal) duct tape and it has held up great for years. I tried normal duct tape and that only lasted one day at the track before it melted into goo. (The duct tape just seals a seam in the sawed open metal cap and keeps the grease from coming out.)
-Chris

carnut169 · carnut169's Garage

Thanks again. I guess I will give it a go. Just ordered 4 new boots, grease, a Bentley manual, the tool required for removal, a soft socket and a new set of floormats (got to get something fun) for almost 1/2 of what I was quoted for the boot replacement. I may need your help when the parts arrive....