Final drive taper roller bearing - how to replace?

[deftflux]

True. Mine are in good shape, though. The previous owner greased them regularly. He even gave me his tube of lube so I could take over.

So the tool arrived today, and I couldn't resist using it. Easy peasy! It was out in a few minutes.

[Laitch]

Good work, deft! Maybe you'll be able to lease that tool to other members.

[Elipten]

Always pays to have the proper tool for the job.

[K1300S]

Well done!

Looks like an excuse to buy another cool tool!

[deftflux]

Always pays to have the proper tool for the job.

Yeah, I also paid a lot to have the proper tool... But at least it performed as expected.

I have to say, I was impressed by the quality of the tool.  The counterstay feet have notches in them, so I could actually anchor them against the circular rim, which was the only level thing I could really use.  Took some time to get it set up, but it started pulling the race out right away.  I had to reset it once after there was more room underneath to grab the race.  Then it was smooth sailing.

I'm just waiting for parts now.  The new taper roller bearing will arrive soon.  The rest of the parts are from Motobins, so it will be a few weeks.  I'll update when I have more progress.  Maybe I'll do a write-up or video when I'm done for anybody else who has to do the roller bearing.

[deftflux]

I got the new outer race installed.  It was really easy.  Here's how it was done:

First, I happened to have some dry ice left over from another project, so I put the new race in the dry ice.  (Though the freezer might have worked just as well.)  After cleaning up the housing and removing the plastic breather cap, I put it in the oven at 240 degrees Fahrenheit.  (This is just under 120 Celsius, which is what the shop manual said.)  After 15 minutes, I took it out of the oven and put the frozen race in place.  It didn't drop in right away, so I put the old race on top of it to use as a punch.  I noticed that the race wasn't quite centered, so I took a dead-blow hammer and tapped the highest edge.  After only 2-3 taps, it centered and dropped right in!  Now that the temperature is equalized, it's pressed in snugly.

[F14CRAZY]

reminds me of recently having to replace the rear brake drum cylinders on my wife's car...propane torch and Freeze Off...works everytime. Crazy how heat and cold make things easier

[deftflux]

Totally.  In the past, before I knew the temperature trick, pressed-fit things used to be a huge pain!

Now I'm just waiting for the rest of the parts, and then I can finish everything up.  Provided that I won't need different shims...

[deftflux]

The final drive saga continues...

When I separated the crown wheel from the housing, I discovered that the shims were all chewed up!  Well, one of them was; the other one was still pretty much intact.  (They were the same size, each measuring 0.30mm.)  Also, the crown wheel bearing actually checked out pretty good.  I'm thinking the metal shavings I saw on the drain plug were actually from the shims!

There wasn't any evidence of the outer race of the crown wheel spinning against the housing, although there is some evidence of heat there.  I'm still confused as to how the shims got damaged.

Anyways, that explains the uneven wear on the taper roller bearing.  Rather than being preloaded, there was play resulting in the bearing not being fully seated.  (Assuming that it was properly shimmed before, 0.20-0.25mm of play instead of 0.05-0.10mm of preload.)  The play in the wheel that I felt was actually from the lack of shim rather than a bad crown wheel bearing.

So, I have to re-shim everything.  Turns out the new roller bearing is somewhat deeper than the old one, requiring a smaller shim behind it to maintain proper backlash on the gears.  I was able to find an assortment of shims of various thicknesses that allowed me to experiment until the backlash was within spec.  Finally, I measured the size of the crown wheel shim needed.  Interestingly, according to my measurements, it needs 0.60mm, which is exactly the combined size of the chewed up shims that I took out.  The new shims have been ordered.

Some day I'll finish this thing...   :dunno2:  Has anyone here seen crown wheel shims get chewed up before?

[jjs1234]

I was going to suggest slowly taking a dremel to it. They collapse inwards when you cut through it enough. Easy to pull out.

But now you got it I am wondering...

One of my races on my swing-arm (Right Side) seems to be in the same predicament.

I am trying to remove it but there really isnt much to grab onto with a standard puller.


Can I rent? haha  :hehehe

[deftflux]

What is the inner diameter of the race you are trying to pull out?

Earlier in this thread, there is a tool linked to for $40 that will work for a 33mm inner diameter.  I talked to the guy who sells them.  He said "maybe" up to 35mm.  The tool I have is only good for diameters between 35-46mm.

However, I was at Harbor Freight the other day, and I saw this tool (see attached picture).  Half the price of the official tool that I bought, and it's a kit that covers a much wider range of diameters.  But it is a slide hammer instead of using a counter-stay.  I personally am not a big fan of slide-hammer-type pullers, but it would probably get the job done.

[jjs1234]

I ended up cutting the dang thing out.  :dunno2:

They have new replacement bearings for 20$ for the swingarm. Thinking of just getting those. I dont know what the chances would be of getting a race.

[deftflux]

I couldn't find only a race for my bearing either.  But chances are if the outer race is damaged, so are the rollers and inner race, so it's best to replace them together anyway.

When installing, be sure to use the heat trick.  Otherwise, you risk shaving some metal off of the mating surface.  The BMW manual says to heat the swing arm to 80 degrees Celsius.  If you've removed any heat-sensitive parts, you can stick it in a preheated oven for 15 minutes (be sure to warn the wife), or else a heat gun will work.  If I were you, I would also stick the new race in the freezer.  If you do it right and keep it centered, it should slip right in without any force.  If you only get it part way (once it makes contact, the temperatures can equalize pretty darn quick), you should be safe pounding it in from there.

[K1300S]

I would be surprised if you could just find a race.  bearings should always be replaced as a set...inner race/rollers and outer race.

[jjs1234]

Ill do that.

Grease it beforehand too... :2thumbup:

[deftflux]

The BMW book does say to grease the bearing before installing, but if they're referring to greasing the outside of the outer race in order for it to slide in easier, then I don't know how I feel about that.  It's supposed to be a pressed fit, but the grease would make it easier for the outer race to spin, which it shouldn't.  With enough temperature difference, it should slide right in without any grease.  I've done this tons of times with the crown wheel bearing in the housing, no grease needed.  But that's just my personal opinion, and the swing arm might be a different story... 

[K1300S]

correct.  no grease behind the race.