My rear end

Raven · 03-22-2006, 02:51 PM

Isn't this a lovely mess!!

and it's mate

Notice the ring gear is in perfect shape!

When I asked the mechanic at the dealership (name with held) what could cause this, he said "you didn't change the gear oil often enough"

I could understand that statement if it were the bearings (still in good shape), but, it is only one gear effected. Smacks of poor quality!!

Now comes the really bad part, $1,200 to rebuild it, 1K for a new one.

WTF is that thing made of to be worth 1K?

60k miles and now it appears I have to spend big bucks to get it going again.

I'm checking the salvage yards.

If anyone has a better idea let me know.

tbsstunta · 03-22-2006, 02:55 PM

What were the symptoms leading up to this?

Raven · 03-22-2006, 03:03 PM

No symptoms!!

I rotated the wheel with my hand and noticed something was wrong.

The rest is history.

ErricZ · 03-22-2006, 04:04 PM

Moybin · 03-22-2006, 04:52 PM

Just dipping into my limited knowledge I would say that the pinion had a bad heat treatment. The failure mechanism looks like brittle fracture. The fact that the ring gear appears to be in perfect condition bolsters my belief. Those two components should have similar heat treatments to create tough materials with good wear qualities.

It seems you can see some metal deformation in the housing right at the face next to the gear failure. Possibly the chips being forced into the aluminum.

I would look for a used unit, drain it, flush it, fill it up with oil and take off.

1100s nut · 03-22-2006, 04:54 PM

Lack of oil change, I would think, would leave scoring marks on both R&P not just a chipped pinion gear. I thought this was part of the bike you could not destroy. I would look for used.
Lane

Flatbutt1 · 03-22-2006, 05:00 PM

$1K for a ring gear? How can that be correct? What else is in the ring assembly or is it the R&P set?

Raven · 03-22-2006, 05:13 PM

Quote:

Originally posted by Flatbutt1
$1K for a ring gear? How can that be correct? What else is in the ring assembly or is it the R&P set?

1K for a new unit.

1,200 to rebuild mine

Raven · 03-22-2006, 05:18 PM

I'm looking at used ones on line.

The S is a little harder to come by, but, there are lots of others that would fit. However the gear ratio is different.

What is the differance between 33/11, 32/11, and the stock 33/12?

How much will it change performance?

$350 is the highest price I have seen so far. Far better than what I was qouted.

gigantic · gigantic's Garage

I've got a 2.91:1 ratio (32/11) abs Final drive from an R1100Rt that i'll sell for $150
pm me if you're interested

dee jones · 03-22-2006, 05:49 PM

Try Fred Roland at cyclesrecycled.com or cyclesrecycled@charter.net The last time I was there he had a S he was parting out. Good luck.

jclark · jclark's Garage

Ouch! I hope you find something soon..

jeff

on2wheels52 · on2wheels52's Garage

My Guzzi little twin gears looked similar but pinion bearing was bad (at 12 k miles). The original design wasn't getting enough oil to that bearing. That ran $900, gearset ordered from Italy.
I'd be looking for used.
Jim

Joe · Joe's Garage

Raven ck your PM...............I have one non abs

pwillikers · 03-23-2006, 04:57 AM

Those prices are monopolistic and infuriating. Lucky to have resources on this list to help out. The pinion endures much more stress spread over many fewer teeth than the ring so it should be the one to go but not changing the oil enough would cause wear on the teeth faces and bearings not the failure your seeing. That's either a faulty part or trauma induced - in my humble opinion. I'd never contradict an objective, experienced mechanic. Good luck. It seems you've got reasonable options now.

dee jones · 03-23-2006, 05:23 AM

Raven, Check your PM, Fred's got one for you.

pdonnell · 03-23-2006, 05:55 AM

The newly purchased power commander won't fix that?

SergioK · 03-23-2006, 06:26 AM

I don't buy the "you didn't change the gear oil often enough" line. Maybe bad/worn gear oil would cause more wear but not that.

Rapid Dog · 03-23-2006, 07:34 AM

Raven, I'd like to know what dealer you went to...PM me.

BMW Atlanta · 03-23-2006, 09:02 AM

I am running a 32/11 gear set in one of my final drives which equals a 2.91 and I like it. the 33/11 is a tad too short for any highway use and gearchanges out of the corner are a little too frequent. You need to do your research if you are going for another final drive. The K bike FD's will not just bolt on and you will need to compare speed sensors and abs sensors on any FD's from R bikes to make sure they are interchangeable. There are many many possibilities for a replacement.