Wheel bearings...1 or 2? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Frodo · 05-05-2011, 08:59 PM

Pelican Parts advises one to replace wheel bearings in pairs. Is this necessary, if only one is bad?

Dave928 · 05-06-2011, 04:25 AM

no. do what you want, but the other one DOES have the same milage as the bad one.

it's called preventative maintenance...

Frodo · 05-06-2011, 05:14 AM

Fair enough (and true). There is a little history that you're probably unaware of: A year or so ago I had a little problem on cold, slick, wet asphalt, doing a complete 360 and smacking some curbing on the right side, the same side that the deteriorating wheel bearing is on. Not real hard, mind you, but you suppose that might have sped things up, bearing-wise?

I've wondered that. In any case, in a now 10-year old Boxster with 57K, I figure I'll have lots of other ways to spend my money in the next year or two. Don't get me wrong, I'm a big believer in preventative maintenance, but finances require I concentrate on maintaining those systems which, if ignored, surely and predictably lead to deterioration of the well-being of the car overall. Those 3 remaining non-noisy wheel bearings? Gonna run 'em til they die.

JFP in PA · 05-06-2011, 06:01 AM

Quote:

Originally Posted by Frodo

A year or so ago I had a little problem on cold, slick, wet asphalt, doing a complete 360 and smacking some curbing on the right side, the same side that the deteriorating wheel bearing is on. Not real hard, mind you, but you suppose that might have sped things up, bearing-wise?

Definitely.

thstone · 05-06-2011, 06:32 AM

They don't "have" to be replaced in pairs as there is no safety or mechcanical reason to do so, just a good idea from a preventative maintenance point of view.

In your case, since you have a good idea about the event that led to the right side bearing's early demise, you're probably fine just replaceing the right side.

sasha055 · 05-06-2011, 06:57 AM

If you're paying a shop to change them, change just one, there is no discount for changing more then one, ie if 1 bearing change costs 500$ to replace (seattle prices) two bearings will be 1000$

If you're changing them youself, might as well change both, bearing is cheap and after you've done it once, second bearing is a lot easier.. plus you'll have to do an alignment if you're doing rears so might as well get it all done.

Thanks
Sasha

RandallNeighbour · 05-06-2011, 07:19 AM

bearing changes on a wheel hub opened a real can of worms for me. To get to it, you have to take off most everything from that corner of the car suspension-wise.

It's a wonderful time to replace a strut, tie rod, control arm or two (or three in the case of the back wheels) because there's no additional labor to take out an old one and put in a new one.

The can of worms is that you should not replace just one strut and they aren't cheap.

You may want to invest in a new lower control arm on that one corner and have the mechanic put that in when he takes the old one off. These wear out way too prematurely on our cars and cause some nasty-loud squeaking when you go over bumps or turn the wheel hard and go into a driveway. It's caused by the steel bit wearing through the rubber gasket and rubbing against the aluminum.

I will say this though... I had all four wheel bearings and most of the suspension swapped out on my car a couple of years ago and it now drives like a brand new car and it's QUIET. I had no idea how noisy worn suspension parts (loose, clanking, and random squeaking that was hard to pinpoint) and nearly-worn out bearings made the car.

JFP in PA · 05-06-2011, 07:36 AM

As Frodo has the SIR tooling, he will not need to pull the suspension apart to change the wheel bearing.

Frodo · 05-06-2011, 12:58 PM

Quote:

Originally Posted by JFP in PA

As Frodo has the SIR tooling, he will not need to pull the suspension apart to change the wheel bearing.

Bingo. Actually, not quite yet...but it's on it's way. (Since I smacked the right rear as well as the right front, that may be the next one to go. Figured I should go ahead and spring for the kit now.)

Steve Tinker · 05-06-2011, 02:22 PM

What exactly does the SIR tools consist of.....

JFP in PA · 05-06-2011, 02:51 PM

SIR produces a broad selection of specialty tools that allow the removal and installation of both front and rear bearing assemblies without the use of a conventional bearing press. This allows the bearings to be changed with the suspension components still in the car rather than removing them and taking them to the press; big time saver for shops.

Their websiste http://www.sirtools.com

jhandy · 05-06-2011, 07:46 PM

Drawing from my memory of changing out my springs, how exactly can you take the bearing out without taking the whole thing apart?

IE: How do you get the bearing out without removing the axle....How do you remove the axle without removing the hub/spindle.....How do you remove the hub/spindle without unhooking everything?

Trying to learn tricks, because changing the springs was an easy job.....but it took me every bit of 4 hours per corner.

JFP in PA · 05-07-2011, 07:23 AM

With these tools, you do need to remove the rear axel (comes out with minimal “persuasion”), then the tool is used to pull the hub and then the bearing. The installation is the reverse. On the front, the tool accomplishes the same type of task, but in either case the struts, carriers, etc. do not have to be removed from the car, which dramatically reduces the amount of work involved. Nice system; and it has adaptors available for just about any make (including Asian and European) or configuration (front drive, rear drive, four wheel drive). Not cheap, but well worth the investment……………

gschotland · 05-08-2011, 01:09 PM

The SIR Tools "B90-P" Porsche specific kit is ~$249, around half the cost of the B90 universal kit JFP posted details on below. I have no experience with either.

JFP, since you obviously have experience with this kit, can you verify that the B90-P kit will do both front & rear bearings. SIR Tools site implies this is "all you need," but doesn't come right out and say it.

JFP in PA · 05-08-2011, 02:19 PM

To be able to do both front and rear, and the hub extraction, you need the B90-P plus the B90-3 bracket (~$85) the B90-3J horseshoe adapter (~$35), which is one reasons why a "Master" kit starts to makes sense:

The B90-3 backet and "J" horseshoe adapter:

The basic B90-P:

The basic "Master Kit":

gschotland · 05-08-2011, 09:38 PM

What is required for the front only? The basic B90-P kit? I'm not sure I have the stomach to take on the rears.

How would you rate the level of difficult for each job? I can handle 3 wrenches (out of 5) and may be temped to try a 4. Playing around with the axle shafts makes me a bit nervous because if I screw them up replacement is big $.

insite · 05-09-2011, 03:58 AM

gary -

the rears really aren't much more difficult than the fronts. if you have the SIR tool & can do the fronts, you can do the rears. the trick to simplifying the rears is tooling related. if you have a base boxster, the axle bolts are shielded by the CV boots & are tough to get at. order a set of LONG hex sockets. you need a 6mm hex key socket that's about 5" long. i got mine from harbor freight. you also need a 32mm socket for the axle nut.

BTW, the SIR tool requirements are identical front to rear. in fact, the carriers are identical parts on the base boxster. the S uses a slightly larger bearing, but the standard SIR kit for the boxster will work fine on that as well.

if you do the rears, be sure to clean the axle bolts with brake cleaner & use some red loctite. the passenger side has a tendency to unscrew itself.

BYprodriver · 05-09-2011, 09:04 AM

Quote:

Originally Posted by Frodo

Bingo. Actually, not quite yet...but it's on it's way. (Since I smacked the right rear as well as the right front, that may be the next one to go. Figured I should go ahead and spring for the kit now.)

I would clean & inspect the wheel carriers for damage & cracks also!

RandallNeighbour · 05-09-2011, 09:06 AM

Oh, and don't forget to buy new caliper bolts. They one-shot use pieces according to Porsche and should not be reused. Fortunately, they're a typical in-stock item and not terribly expensive.

JFP in PA · 05-09-2011, 09:49 AM

Quote:

Originally Posted by gschotland

What is required for the front only? The basic B90-P kit? I'm not sure I have the stomach to take on the rears.

How would you rate the level of difficult for each job? I can handle 3 wrenches (out of 5) and may be temped to try a 4. Playing around with the axle shafts makes me a bit nervous because if I screw them up replacement is big $.

As mentioned by others, there is not a lot of difference from the front to the rear other than the axles. To do either end, you need pretty much everything pictured, or you will need a slide hammer in place of the hub tooling (bracket and horseshoe).

As for difficulty, I don't find it difficult at all, but as I am equipped differently and do this for a living, perhaps that would be better answered by someone that has done it as a DIY..............