Rear Wheel Bearing Needs Replacement (Right?)

Smoove1010 · Smoove1010's Garage

R-n-R'd the driver's side rear wheel bearing on my 87 Carrera today using the plumbing-fittings-and-threaded-rod-"Pelicanite" tool, worked like a charm. This bearing was bad - even before the axle nut was loosened, the hub/axle wobbled severely.

The passenger side is nice and tight - barely a perceptible wobble - less than a millimeter, even with the axle nut removed. The hub spins freely, but I don't like the way the bearing sounds - it sounds dry, as though there's no grease between the balls and races. I'm inclined to replace this one too while I've got the axle shafts out for CV rebooting. Am I wasting my time and money, or is this a no-brainer?

gtc · gtc's Garage

I replaced mine at the same time. I figured that way I wouldn't have to mess with them for another 25 years.

Danny_Ocean · 03-24-2012, 08:15 PM

If you don't replace it, you'll find out its' bad after you get everything back together and the car is on the road 100 mi. from home.

Rexs-911T · Rexs-911T's Garage

Yes, just replace it now while you in the mode, you have all the tools and experience on the first. I always replace mine both when ever one is bad. The second one may not be far behind!!

ivangene · 03-25-2012, 08:59 AM

I replaced one....a year later replaced the other one - I agree if one is bad the other is close...how close..IDK, but for sure you will be changing it at some point in the not to distant future

hcoles · 03-25-2012, 11:51 AM

remember to put the tin on before reassembly or you will buy a new bearing probably

Smoove1010 · Smoove1010's Garage

It's unanimous, and I guess I knew what I needed to do all along. This way, I won't have to think about that bearing again for a long time... Tonight I'll place the 5th order for parts from Pelican in as many weeks. (Hey Pelican, this business model is a stroke of genius!) I used the SKF bearing for the driver side, I think I'll try the FAG for the passenger side to see if there's any difference in installation or longevity. In the meanwhile, my calipers are about rebuilt, the CV joints will be rebooted, cleaned and repacked, and the Ebrakes refreshed. I'm really enjoying this project, I've learned a ton in the month or so that I've owned this car - with lots of help from this forum - but I'm also looking forward to doing less wrenching and more driving.
..and then the interior refresh starts.

BTW - if anyone uses mineral spirits for cleaning parts, bearings, etc., don't buy a gallon of the so-called "green" mineral spirits without trying a smaller quantity. It just doesn't work as well as the good-old toxic smelly stuff...

GK

hcoles · 03-25-2012, 04:48 PM

Quote:

Originally Posted by Smoove1010

It's unanimous, and I guess I knew what I needed to do all along. This way, I won't have to think about that bearing again for a long time... Tonight I'll place the 5th order for parts from Pelican in as many weeks. (Hey Pelican, this business model is a stroke of genius!) I used the SKF bearing for the driver side, I think I'll try the FAG for the passenger side to see if there's any difference in installation or longevity. In the meanwhile, my calipers are about rebuilt, the CV joints will be rebooted, cleaned and repacked, and the Ebrakes refreshed. I'm really enjoying this project, I've learned a ton in the month or so that I've owned this car - with lots of help from this forum - but I'm also looking forward to doing less wrenching and more driving.
..and then the interior refresh starts.

BTW - if anyone uses mineral spirits for cleaning parts, bearings, etc., don't buy a gallon of the so-called "green" mineral spirits without trying a smaller quantity. It just doesn't work as well as the good-old toxic smelly stuff...

GK

I'm curious, if you don't mind looking, one model of bearing may have the seal slipping on the inner race and the other slipping on the outer race, I've seen this but don't have the exact makes/models handy

wildcat077 · wildcat077's Garage

Yes there is a difference in the way the bearings are made ... i know that one is better than the other,it's in one of the many posts on this forum ... lol

I bought the removal/install tool from Arnnworx and will be tackling both sides eventually !

Cheers !
Phil

Smoove1010 · Smoove1010's Garage

Quote:

Originally Posted by hcoles

I'm curious, if you don't mind looking, one model of bearing may have the seal slipping on the inner race and the other slipping on the outer race, I've seen this but don't have the exact makes/models handy

The seals slipped on the inner race for the SKF, but I also noted that the inner races on the SKF feel a bit loose - they are obviously entirely dependent on the axle nut being torqued down to spec. This is a bit unnerving when the hub is pressed in and the wobble is noticable. I expect that when the stub axle is back in place and everything is torqued that this wobble will go away.

The failed driver's side bearing was a FAG. According to our host's catalogue, the SKF is the OEM supplier, which would indicate that the driver's side had been replaced at some point by a PO. Interestingly, the old FAG bearing had a seal that slipped along the inner race, but as far as I could tell, there was only one layer of seal. I recall from one of your posts on the subject that the newer FAG bearing had two seals, one slipped on the inner race, the outboard seal slipped on the outer race (if I have that right.) I'll let you know how the new FAG bearing looks when I get it.
GK

hcoles · 03-26-2012, 06:40 AM

It has be some time now and my memory isn't great.
I think there are two questions now under discussion:
1 - Are there seals on one or two sides? (I about 99% sure the answer to this is yes)
2 - What race do the seals slip on? ( I don't recall that one side was different than the other, but good question.)

What I do remember is that the indicated original type bearing had the seal slipping on the inner race and one of the other brand/cheaper bearing offered had the seal slipping on the outside race. After some reading I found out the bearing size is not uncommon, but may be used as a front wheel bearing in medium sized cars that have front wheel drive. I'm guessing that in that application having the seal slip on the outside race has some advantage, e.g. the outside race is moving compared to the 911 with the inside race moving. My opinion, as already mentioned, is to have the configuration with the seal slipping on the inside race to keep in lube and get out of the pile of debris that may accumulated in the arm.