Rear wheel bearings: replace in pairs?

It's time to replace one or both rear wheel bearings in my iX. It's been a little noisy (but not too awful) for a while, and last time a mechanic looked at it he confirmed that one of them needed replacing. His recommendation was to leave the other one alone, but my inclination is that if one of them is bad (after 150K miles), the other one is probably not far behind. What's the thinking here? Replace both of them, or just the known bad one?

Since this is one job that I won't do myself, labor costs become an issue, but I don't think the labor costs would be any different doing both at the same time vs. one now and one later.

__________
Dave
'91 325iX

I replaced one about 100,000km ago and no signs of trouble from the other one yet. Knock on wood

I replace mine in pairs. You can replace just the one that is making noise and still be fine though...

Just one will do, bearings can last very long if they're good.

Add another vote in the "replace only the noisy one" column.

The old quiet bearing might even outlast the one you put in to replace the the one making noise. A lot depends on the care of the installer.

John

I vote for doing both and getting it over with, then you don't have to worry when the other goes at an unfortunate time. Make sure the CV's have oil too while you're at it. Loctite the axle bolts on the rear end flange's also.

This is kind of fun. I've asked this question in three different places, and so far the advice to replace one or two is split just about 50:50.

Lacking a clear consensus, I am falling back to the first principal that has served me well through the years: "If it ain't broke, don't fix it." So I* will be replacing just the known bad one, and seeing how long the other one lasts. If it goes sometime later, I'll replace it then.

(*)By "I", of course, I mean "the guys at the garage down the road." I do all the work on my E30 myself, but when it comes to replacing rear wheel bearings, that doesn't count as "work" -- more like "self-inflicted pain."

__________
Dave
'91 325iX

Quote
Dave_G

(*)By "I", of course, I mean "the guys at the garage down the road." I do all the work on my E30 myself, but when it comes to replacing rear wheel bearings, that doesn't count as "work" -- more like "self-inflicted pain."

Actually, it's not too bad IF you have the right tools (without them it's a pin in the neck). Unfortunately those tools are specialized and expensive (for DIYers) and you seldom use them....

Quote
igor325

Quote
Dave_G

(*)By "I", of course, I mean "the guys at the garage down the road." I do all the work on my E30 myself, but when it comes to replacing rear wheel bearings, that doesn't count as "work" -- more like "self-inflicted pain."

Actually, it's not too bad IF you have the right tools (without them it's a pin in the neck). Unfortunately those tools are specialized and expensive (for DIYers) and you seldom use them....

I agree. I did this job myself by renting the tools from Koala Motorsport. The job wasn't bad at all, and the rental experience was great. Unfortunately, I believe that Koala has gone out of the tool rental business now. One may be able to find tools by asking around their local car club chapter, some clubs have formal or informal tool loan arrangements. But if you can't get the real tools for this, I would be loathe to attempt it.

That said, when I did mine, I replaced both, because it had been 160k miles or so and I figured since I had the tools, I might as well do both at the same time. If you're having someone else do the work, I guess I don't really see the urgency to do both at once.

Cab
1990 325i(s)
2004 325XiT

Quote
Dave_G
This is kind of fun. I've asked this question in three different places, and so far the advice to replace one or two is split just about 50:50.

Lacking a clear consensus, I am falling back to the first principal that has served me well through the years: "If it ain't broke, don't fix it." So I* will be replacing just the known bad one, and seeing how long the other one lasts. If it goes sometime later, I'll replace it then.

(*)By "I", of course, I mean "the guys at the garage down the road." I do all the work on my E30 myself, but when it comes to replacing rear wheel bearings, that doesn't count as "work" -- more like "self-inflicted pain."

Okay Dave, that sounds fine, and I think, the thirty not being your primary car that you trip in, you can do just the side that's hurt now and leave the other side go. Myself, it's a little different; I use the thirty for all kinds of long trips to the middle of nowheresville so my thinking is a little different and it Is my only trip car- not to say things can't go horribly wrong with an older car but...... you try to cut your odds down where you can

Good luck and don't forget the loctite B)

Rick

Quote
rkj
I think, the thirty not being your primary car that you trip in, you can do just the side that's hurt now and leave the other side go. Myself, it's a little different; I use the thirty for all kinds of long trips to the middle of nowheresville so my thinking is a little different and it Is my only trip car

Actually, the iX is my primary car. It's my daily driver to work, and most importantly, the way that I get over the snowy mountains to get to skiing all winter. So yeah, I'm driving a lot on little-travelled mountain roads in the boonies (more often that not, with no cell phone reception). So it does matter a lot to me that my car not break down. But wheel bearings are the sort of thing that usually give you warning, and are unlikely to fail suddenly and catastrophically. At least that's what I hope.

__________
Dave
'91 325iX

Quote
Dave_G

Quote
rkj
I think, the thirty not being your primary car that you trip in, you can do just the side that's hurt now and leave the other side go. Myself, it's a little different; I use the thirty for all kinds of long trips to the middle of nowheresville so my thinking is a little different and it Is my only trip car

Actually, the iX is my primary car. It's my daily driver to work, and most importantly, the way that I get over the snowy mountains to get to skiing all winter. So yeah, I'm driving a lot on little-travelled mountain roads in the boonies (more often that not, with no cell phone reception). So it does matter a lot to me that my car not break down. But wheel bearings are the sort of thing that usually give you warning, and are unlikely to fail suddenly and catastrophically. At least that's what I hope.

That's, for the most part, true. I blew one in maine (about an hour out of Canada on the coast) and just made it home. it started to make noise about half way home and by the time I got a mile from home (on the east end of long island) the wheel started to come off... I kicked the wheel back in and made it to my driveway..... just..... still going for the one side Dave have you done the fronts yet?

IX'... so many bearings and such

Could you give an update on this job, and how much you spent (where you went would help too), although I don't usually get up your way it would give me an idea what this job cost's

Good luck, Rick