R60/5 rebuild nears completion – with some puzzles. . .

The mechanic didn't lose the washer off your bike. He lost the one off his bike. Guess where he got another one?


My view of human nature is not doing well...

Agree Bill. The Teflon seal may not have the same profile or contact patch.

I think everybody has behaved rather well. I try, or maybe should say I don't have to try. I give it my best shot and if somebody shows me the errors of my reasoning then I learn something. I didn't see any name calling. I think in the end we all do a better job because we have looked at the problem from another's stand point. Use a socket or a block of wood or tool made from unobtainium, The next time any of us puts a rear oil seal in we will look at it with new eyes. I think that is truly priceless.

Did anybody else think Plaka's Super Glue idea was really funny? I'm afraid he may not of been joking though.

For a googler you haven't googled much. Not that that surprises me.

I couldn't tell you how many times I am asked for the basis of my opinion and when I give it I am then accused of daring deeds blah blah. It's as if most of us can't see a bait and switch when one is right in front of us.

That long explanation is forgetting the fact that BMW first recommended soaking the later seal in oil for some time and preforming the seal and whatnot. Knowing that makes your explanation nonsensical.

The later seal has a completely different contact pattern on the flywheel. It contacts a much, much wider area than the typical rubber seal. That's probably the reason why they work so much better. Most of the time it will be impossible to miss a groove in the flywheel left by a rubber seal. The newer seal's contact area is too wide to miss the groove by setting the seal shallow or deep. I know it's just more blah blah but I have noticed this from installing a great deal them.

For sure. Oil seal technology has changed so much in the past few years. And I'm accustomed to the old-school lipped seal with the garter spring and the little spiral grooves to persuade oil to go back in. This filled teflon seal is much akin to magick, but I'll have to get used ot it.

--Bill

For our airheads it's been available from BMW for 30 years now.

glad it's working out for you.

Just coming up for air and have to share this with you. Apparently I have to learn everything the hard way. Tonight I planned to install the new duplex chain and crank sprocket. Remember how paranoid I was about blocking the crank? Because if you don't and something goes wrong, the results can be nasty? Well. . .

I thought I had everything figured out - while heating the new sprocket in the oven at 280F, I practiced with the old sprocket. I slipped it onto the shaft with just enough force to center it. I tried to pull it off but it was cocked on the shaft. I tugged on it just a little too hard I guess. That's when I heard a soft 'clunk'. Uh oh.

Not fully believing the obvious, I tried gently turning the crankshaft - bad idea. Completely seized. Sh*t!!!!!!!! Next to the $3000 o-ring hazard, this is the one to avoid at all costs and I had stepped right in it.

With rising blood pressure, I scanned the manual, the web, anything that could offer hope. Finally found a short reference by Snowbum that said there is a TINY chance to get the thrust washer back on its pins by accessing through the right side of the engine case. He said it probably wouldn't work but it was worth a try. He didn't offer any details.

I'll cut to the chase. After half an hour of gentle prodding with a thick copper wire (so that I didn't scratch anything), I managed to get it back on the pins. Disaster averted.

Ah, so the transmission and flywheel are off? Don't feel bad, I would be hard-pressed to remember to "block the crank" from the back when doing a crank pulley replacement. Good public announcement there...

Glad it went back on the pins (eventually),

--Bill

Some progress today - installed 'modern' rear main seal today thanks to borrowed tool (much obliged James!) Also installed oil pump with new o-ring, flywheel, camshaft, crank sprocket (very tricky) and duplex chain (trickier). Read other inmates' accounts about the tiny e-clips releasing and dropping into the oil pan. Has anyone had recent problems with these IWIS clips? Maybe it was a bad batch circa 2009.

My idea of a dental mirror -



No wonder the chain was sloppy -

Torqued flywheel tonight with fresh bolts - should have used the old bolts because when fully torqued, crank had set like concrete (had formerly turned freely). Pulled off flywheel and noticed spalling of outer thrust washer I hadn't seen before.



Had to have a better look. Goodbye new stretch bolts, teflon seal -



Thought for a moment it might be related to crank slipping off journals but unlikely. Here's a closeup -



Flywheel mating surfaces seem OK. Suddenly, I'm learning about crank end float. BTW, I put the flywheel back on without the main seal and everything spun effortlessly. I'm confused.

Darn, now that is puzzling. That spalling wasn't caused by the washer slipping off of the pins, or anything I can think of offhand. And odd that the crank turns OK with the flywheel (and this thrust washer??) installed but w/o the seal. And odd also because typically a used thrust washer will have a coppery-appearance since the top layer of the bearing material will wear off. Did you have that thrust washer out for any reason? What does the other side look like-- could you have had it out and flipped it, and had a flake of grit get under the washer? No corresponding marks that I can see on the flywheel surface. Was there any "swarf" in the seal cavity?

The only other explanation is prankish spririts (poltergeists, if ya will)... :eek1

--Bill

I agree,Bill - kinda creepy. But to answer your questions, no, never had the thrust washer off before and, yes, crank turns freely with this thrust washer on, without the seal and fully torqued. No swarf or debris in the cavity. Here's the other side of the washer -



And, for what it's worth -

Fortunately these are not very expensive as I remember. Since the engine wasn't run it is debatable if the bolts need to be replaced. The safe bet is to replace them.

Is it possible that any mysterious liquid got spilt onto the bearing? There are some things that eat the Bronze material a bearing is made from. Anti-Freeze comes to mind but I don't know how this or anything else got to the bearing?

Very strange indeed.

Mysterious. That thrust washer has been in that position forever-- see the oil drain hole "shadows". The damage doesn't look recent or like an impact or gouge-- almost like a manufacturing defect. This washer may be reusable, or to be safe, order one the same thickness and another the next thickness smaller.

I be puzzled.

--Bill

Where is the spalling in relation to the oil drain "shadows"? If it's directly on the other side my guess is some sort of oil additive did'nt like that bronze material.

On second thought, possible frozen water damaged the bearing as the bike is from the great white north

All good points but I now realize the real issue is the bronze has been almost completely worn off the face of the washer (I can see traces of it in the cold light of day). This is probably a blessing in disguise - I was wondering why the flywheel mating surface wasn't scored. Will definitely need a new thrust washer and will try to figure out the thickness calculation tonight - I understand they come in three thicknesses.

Also, I am wondering if I put the RMS in far enough - left it out about 1mm and maybe that's why the crank was binding when I torqued the flywheel bolts. Don't worry, will definitely buy new bolts.

Sorry if this is a bit tedious - it's all been covered in ADV many times, I'm sure. This stuff is nerve racking for hobbyists like me.

Put the seal back and leave it 1 mm proud like you did before. Mark up the face of the seal (that faces the flywheel) with a sharpie marker. Put flywheel on and gradually tighten the bolts until it just binds. Then turn it around a couple of times and take it off. See if the marks on the seal face are still there.

The thrust washer would need to be massively worn to be bad. I would ignore surface coloring. Lot of times parts have a thin plating to prevent corrosion in the warehouse. In this case the color denotes the size. Put it back, put everything together, torque the flywheel (use the old bolts) and check the crank endfloat. If it is good, just build the fool thing. Replace the flywheel bolts if you want. Personally I wouldn't, they haven't been under torque long enough to matter. But it won't hurt a bit.

If the crank end float isn't good, then measure what you got, take it apart, measure your thrust washer and you know what to buy.

I should add, a thrust washer is monolithic. Same material all the way through. it's not like there is some thin layer of bronze. Bronze washers are sintered---made of pressed powder. They are porous and hold oil. That's why you use bronze. A Babbit bearing is a little different. You may have a thick layer of the babbit metal on a backer of a different material. But they don't have to be made that way. The thing you got does not look like sintered bronze and the application is inappropriate for a babbit bearing. In fact it's inappropriate for any type of bearing. It's pinned, remember? Try a magnet on it yet?. If it sticks you got a steel spacer.

The thrust washers are designated green (on the inside) and red, on the outside. The other sizes are different colors.

It sounds like maybe the inside thrust washer is off its pins?