Author Topic: Bearing failure survey.  (Read 2069 times)

rocketman

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Bearing failure survey.
« on: March 17, 2005, 06:42:13 AM »
There is a survey relative to crank bearing failures that is in process on P-O.com.  I would like to also run the survey here to broaden the amount of data obtained.  The string explaining the problem and containing the origional survey is here:
http://www.pilot-odyssey.com/8525687400459A41/0/e767e555591aa9ca05256fc60079713a!OpenDocument

The questions are repeated below.  I have added a question pertaining to premix oil used.

As a group we should be able to work out what is happening here. Can everybody please answer the following:

1. Have you had a main bearing failure where the rivets have come out of the bearing(s)?

2. What type of clutch were you running?

3. When did you purchase the clutch?

4. Had you ever replaced the main bearings prior to the failure?

5. Which bearing (clutch side, other side or both)failed?

6. When were the main bearings that failed purchased?

7. What premix oil(s) have you been using and for how long?

If everybody (with or WITHOUT failures) answers this we should see a trend if the problem is the bearings (or any particular batch of them) or if the problem has something to do with the clutches (or any particular batch of them).

PilotSniper

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Bearing failure survey.
« Reply #1 on: March 17, 2005, 07:54:06 AM »
1. Have you had a main bearing failure where the rivets have come out of the bearing(s)?

No.

2. What type of clutch were you running?

PowerBloc.

3. When did you purchase the clutch?

6 months ago from Ludedude. Ran a PowerBloc the previous 1.5 years when the Pilot was purchased.

4. Had you ever replaced the main bearings prior to the failure?

I replaced the bearings with new OEM Honda bearings, but they had not failed.

5. Which bearing (clutch side, other side or both)failed?

n/a

6. When were the main bearings that failed purchased?

n/a

7. What premix oil(s) have you been using and for how long?

Always Yamalube @ 32:1 with 93-octane Amoco Ultimate.
I started out with nothing and I still have most of it left!  :shock:

ludedude

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Some bearing info I picked up.
« Reply #2 on: May 27, 2005, 08:28:09 AM »
Little info from talking with NTN rep:

Steel cage is good up to 12,000 rpm's so little use/need/benefit to go to a phenolic cage. Phenolic cages are more suspeictible to heat and additives in the fuel/oil there are lubricated with. Phenolic are also more suspectible to misalignment than steel cages. Was advised to go to 6306 C3 with welded cages on both sides. Welded cages are 30% stronger than rivited. Then he spoke with someone else and changed that to the new riviting processes used results in rivited cages as strong as welded ones. Main reasons for cage failure is lubrication, or misalingment. The cages are there for guidance only, any misalignment load, vibration or lack of lubrication will strees the cage and contribute to premature failure. Mostoften failure is due to lubrication failure where it is non-exsistent momentarily and causes the balls to skid, when they skid they apply forces which spread the cage.

I was thinking of trying phenolic cages on my next rebuild. Now I guess I won't. But I will be trying C3's on both sides of the crank and switching from Amsoil to Motul.

PilotHawK

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Bearing failure survey.
« Reply #3 on: May 27, 2005, 06:39:04 PM »
32:1 might be the culprit? The stock bearing is a C3 grade. I found these. You may want to be the point man in looking into these. INA is a great bearing manufacturer, and these bearings have a huge dynamic load rating.


http://medias.ina.de/medias/en!hp.ec.br.pr/N3..E_FAG*N306E.TVP2_FAG;azlSjSzFsJWg

ludedude

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Bearing failure survey.
« Reply #4 on: May 28, 2005, 05:28:20 AM »
In 32:1 you're saying what...not enough oil in the ratio?

Isn't the stator side a C2...not identified so it's a C2, and the clutch side is a C3? That was my understanding. THe C3 has more clearance built into it, it's not a tolerance issue, they're made to the same tolerances, but the C3 has more clearance designed into it to allow for greater delta thermal conditions.

That's a roller bearing? Cylinderical rollers, instead of ball bearings? Will they take the axial elongation of the crank? Or is that even taken up in the bearings...is it taken up in the cases?

PilotHawK

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Bearing failure survey.
« Reply #5 on: May 28, 2005, 06:30:55 AM »
Looking at a parts breakdown I have both bearings are C3 clearance bearings. The stator side does have an S designation in front of the 6306 though, and according to this page http://www.bearingworks.com/bearing1.htm indicates that the ring material is stainless.

As far as oil goes, I keep hearing the same thing from several places. Lack of lubrication causing the balls to skid is breaking the cages. OK what does that say??? Honda did specify 20:1. I know that oils today are better than they used to be, but maybe there are fuel/airflow issues in the pilot motor that affect the pilot motor differently than other 2 cycle motors.

While I don't have a pilot anymore, I didn't like having to rebuild mine more than I thought I needed to and I'm sure others feel the same. With 20:1 you should be able to run about any type of oil: pennzoil, castrol, wal-mart etc. It doesn't seem that the high dollar oils are doing what they claim to anyway.

ludedude

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Bearing failure survey.
« Reply #6 on: May 28, 2005, 06:49:22 AM »
Hmm...yeah I looked them up again and you're right, C3 on both sides...yet I know only one of my bearings has the C3 stamped on it..the other did not  :shock:  :?  :?