Anybody had a rear wheel come loose?

[macx]

No BS about it, that's some kind of excitement! But the
kind I can definitely do without.

I'm very sure I torqued it last time I had it off, too, and in
the prescribed stages. Always very conscientious of doing
that any time I install a wheel on anything.

Anyway, came out of the store onto the 2 lane, accelerated,
started around a mild corner in a 50 zone, noticed it was getting
just a little squirrely on the rear, thought I had a tire going flat.
As soon as I felt it, I let off the throttle and started gentle
application of the brakes.

Bike was wobbling, got worse quickly.

Hadn't gotten it even slowed down to around 35 or so when
the wobble got REAL intense, so got her stopped ASAP.

Felt the tires, OK. When I bumped the rear one, I saw the
wheel wobble. At first thought maybe a FD bearing had
gone out, but then saw there wasn't any oil, looked a little
closer (bike was leaning toward that side on the side stand).

To my amazement I saw one of the wheel bolts just about
all the way ready to drop out, and the others were all
loose.

WHEW! That could have ruined my whole day!

The rest of the way home I started thinking "blue loctite".
Don't want THAT happening again!

[omg1010]

No no, no loctite on the wheel screws. Manual says to fix the screws with 50 NM first and let sit for a moment. Then in a second go fix with 105 NM. After a couple of days or 100 kms check again. By doing so these screws will never come loose. Only mistake one could do is apply grease or WD40 or some other stuff on these screws. That may cause such problem.

Man you're really lucky. Imagine you had run at high speed ...

Brgds
Oliver

[CycleRob]

Apparently the wheel studs were not tightened, likely due to some sort of distraction. We've all done that type of forgetful omission, like leaving your keys in a temporary location while unloading or taking off a jacket. That's why the important things should always be double checked at the work session and triple checked anytime afterward if you have the slightest doubt. It's also fun to check the loosening torque when the wheel is removed again for a tire change. Don't be surprised if you see 45 ft-lbs.



Here's a copy-n-paste of what the BMW manual says:

Installing rear wheel
**Attention:
Contact faces on rear wheel drive and hub must be clean and free of grease.
[Integral ABS] The spacer must be clean and free of grease.
• [Integral ABS] Place the rear wheel in position with spacer.
• Hold rear wheel in position at rear wheel drive and hand-tighten the wheel studs with taper rings.
** Attention:
Use only wheel studs with length code 55
Do not oil or grease wheel studs!
• Tighten the wheel studs in diagonally opposite sequence.
• Install brake caliper.
**Note:
[Integral ABS] After switching on the ignition, always wait for the BMW Integral ABS to complete its self-diagnosis.
Do not operate the brake lever until self-diagnosis has completed.
• Check operation of the brake system with the ignition switched on.
--Tightening torque:
Wheel studs, initial torque ............................ 72 Nm
Wheel studs, final torque............................ 105 Nm
Brake caliper to rear wheel drive .................. 40 Nm

[macx]

Hey, now, "have you no faith"?

I s'pose it kinda boils down to that.

Just FYI I do have an oem service manual,
and I do refer to it quite regularly.

That's one of the first things I do when I acquire
any vehicle - get a copy of an oem service manual.

Invaluable not only in making repairs but in
diagnosing problems.

[NoRRmad]

Seems to me that you've had the final drive off and on and off again quite a few times in the last few months, and replaced it with another differently-geared (used?) unit. Any chance that the internal threads have been worn out? You might try some index marks on the bolt heads, and look for rotation. If there's any, I'd drill the bolt heads and safety-wire them.

[macx]

I would tend to doubt the threads are worn -
bolts have always had clean threads, not over tightened, etc.

And really only been off maybe 1/2 doz times - I've had wheels on and off
of esp one of my cars dozens of times and no problems on threads.

I would sure hope they are of better quality than that!
I used to be Main Shop Foreman at a big paving contractor shop
and we had wheels on and off of pickups and trucks many many times
and no problems.

Oh, and FD hadn't been replaced when this happened.

[jfslater98]

This has happened to me. And only once, someone else (a "professional") was left with the duty of reattaching the rear wheel. And didn't torque them to spec. That was a very long evening, think "Trains, Planes and Automobiles". More like "Cops, In-laws and Trailers".

Torque the bolts correctly and they will stay on. Make sure you inspect the rear caliper, as it was the only thing holding your wheel onto the bike.

Now if you'll excuse me, I'll wipe the sweat off my brow from the flashback that this post induced.

[Seamripper]

Wow dude! Horrifying event to say the least!

I'm going out to the garage today and checking my torque. It's been a long time.

(oh, and I hope you put on a fresh pair of underwear after that incident... )

[macx]

think "Trains, Planes and Automobiles". More like "Cops, In-laws and Trailers".

Make sure you inspect the rear caliper, as it was the only thing holding your wheel onto the bike.

Only not NEAR so funny, huh?

I realized that the caliper probly saved my bacon when I got to thinking about it.

[macx]

Wow dude! Horrifying event to say the least!

I'm going out to the garage today and checking my torque. It's been a long time.

(oh, and I hope you put on a fresh pair of underwear after that incident... )

Yeah, that's one of those things that don't really sink in till later. At first, you're
busy getting the wheel back on tight so you can get home, or wherever.

That sounds like a wonderful idea! I'm definitely going to add that to MY periodic check list!

(STRAIGHT into the shower!)