Symptoms of Fan Bearing Failure & Who is Responsible?

[GearGirl]

Originally Posted by ahicks

Somebody catching that bearing on the verge of failure (prior to it actually failing) is something I've never heard of. I can't help but think it would be pure coincidence if they did. As an ME, you should understand how long that bearing (which has a fairly high loading I would imagine) is going to keep spinning once it goes dry/into failure mode of some type? An hour maybe? Kind of a narrow window to catch it prior to total failure given the fact the engine is so muffled in our pushers.

For more/better insight, I might try running that question past people hanging out on a Cat forum though? Thinking you might find somebody with more engine specific experience.

Thank you, will also pursue that approach!

[Arch Hoagland]

Originally Posted by GearGirl

Whoa. I didn't know they pay for repairs, too! Good to hear!

The entire wiring harness that goes to the main control panel for air conditioning/heating/tank levels/battery voltages, etc. was ripped out and wrapped around the rear axle.

RVing isn't for sissies...lol. Bad things happen but that's all part of the game.

I have more horror stories but will spare you the details.

You mentioned if you had any more major incidents you would sell your RV. Well I have bad news for you....

[calhyatt]

Originally Posted by RIDER FAN

I hope this thread dies. You eroded it with your arrogance Gear Girl. Over and out.

I hope the moderator kills this thread. It has degraded to new lows and us no longer relevant to the spirit if this forum.

[NHRA225]

Originally Posted by calhyatt

I hope the moderator kills this thread. It has degraded to new lows and us no longer relevant to the spirit if this forum.

I agree !


Sent from my iPhone using iRV2 - RV Forum

[Arch Hoagland]

To those of you that want the thread closed you can simply click on the Unsubscribe button.

That will close the thread for you.

[Hikerdogs]

Originally Posted by ahicks

Somebody catching that bearing on the verge of failure (prior to it actually failing) is something I've never heard of. I can't help but think it would be pure coincidence if they did. As an ME, you should understand how long that bearing (which has a fairly high loading I would imagine) is going to keep spinning once it goes dry/into failure mode of some type? An hour maybe? Kind of a narrow window to catch it prior to total failure given the fact the engine is so muffled in our pushers.

For more/better insight, I might try running that question past people hanging out on a Cat forum though? Thinking you might find somebody with more engine specific experience.

Actually bearing analysis is more common than you think. It's usually done as a maintenance item in large manufacturing operations. The key is it isn't a one time test. It requires a baseline to be set with multiple examples of the same bearing, and regular periodic inspections. The baseline sets the "normal" vibration range for a particular type and style of bearing under a specific load. The periodic inspections reveal when the vibration starts to go beyond the "normal" range and into the "excessive wear", and eventual "failure" mode.

Close to 20 years ago I setup a bearing analysis program at the company I worked for. The equipment was fairly expensive and required sensors with remote connectors to be attached to any bearing that wasn't easily accessible. Accessible bearings could be monitored by touching them with a measurement tool similar to this.

SKF Vibration measurement tools

More remote bearings could be measured by plugging the sensor into the tool.

After several years of gathering data we could define an expected lifespan for each bearing application. Manual inspection routines were setup and runtimes were recorded. When a bearing reached 75% to 80% of it's expected lifecycle it was replaced to avoid catastrophic failure.

Keep in mind a program like this took several years to develop, and was done with stationary machinery working under controlled load and runtime conditions.

Since we had success in one arena company management decided to expand the program to see if it would work on the fleet trucks. Long story short there were so many variables it was a complete failure. Essentially success in one environment doesn't necessarily guarantee the same outcome in a completely different environment.

[jesilvas]

That's pretty interesting Hiker.

Was the first area of testing on equipment that ran at a certain RPM constantly and never varied? Basically, very few variables?

Essentially what I've gathered is this: The symptoms for bearing failure is it laying on the ground.

[stik]

Originally Posted by GearGirl

I'm not sure how else to say "experienced RV owners, what are some symptoms of fan bearing failure?"

I'm asking for symptoms of Fan Bearing Failure in a diesel pusher. I'm not asking for opinions. And I'm not going to play to some bitter, cynical, misogynistic jerk.

Either reasonable people can provide simple anecdotal experience for me to note, or they can simply move to the next post. I get the distinct feeling some posters get off on giving people as much grief as possible. Pathetic.

WOW! After reading GEARGIRL's orginal post, and all the responses (including the snarky ones) I can only say the snarky comments may well have been deserved. Others have asked for additional info at the beginning, but the OP (that's Original Poster, for ME types) appeared to have a VERY LARGE chip on the shoulder!!! The additional info might (again might) have resulted in a very quick response of something like "I have/had the same set-up and this is what I observed"
Instead you come to a usually very friendly, helpful group of folks and start with the holier than thou attitude typical of a lot of Engineers with lots of education, but no practical experience. I am NOT saying ALL engineers are like that, but we have all met/seen them . . . maybe even here on this forum.

At any rate, I hope the OP has learned that this forum is not the best environment to perform root cause analysis. Most, if not, all folks on this forum are about helping people fix problems based on experience, and yea, sometimes opinion.

I started reading this thread primarily due to it's title:
Symptoms of Fan Bearing Failure and Who is Responsible?

I guess this is the society of where someone ALWAYS has to be responsible when something gets old and wears out? An inspection was done, some things were noted, explanations were given (right or wrong) and were ACCEPTED! Do I understand that you had a mechanic do an inspection and then accepted what the salesman said to dispute the mechanic?

But I will remain optimistic and assume as a ME that the OP will soon come up with a "Perpetual Bearing" than never fails. Opps, nope, wait that would me a Design Engineer that would do that.

ON A SERIOUS note: I hope the OP gets everything resolved and we all learn something. I, for one, have learned to try and remember not to get wrapped around the axle. I don't want to read back through all the posts, but was it ever mentioned that the dealer gave ANY kind of warranty, or was there an "as is" clause buried somewhere in the paper work as is common in lots of used vehicle sales? Just curious.

Best of luck, GEARGIRL, with your purchase and repairs,

[GearGirl]

Originally Posted by Arch Hoagland

To those of you that want the thread closed you can simply click on the Unsubscribe button.

That will close the thread for you.

THANK YOU!

[phil57]

Wow I don't see many threads like this. Thankful for that. I see that you are fairly new and you may not realize how many different Moho's there are. Between gas and diesel there are hundreds of them with all kinds of different drive trains. That in itself makes it difficult to come up with a helpful answer. Then consider that every answer depends on how good of info the OP is giving. I was shocked that you would not give out that info. It is a vital piece to the puzzle and it's up to you to at least do that.
I guess that you can continue on the path you are on and block me also. I would hope that you would apologize and start over. There is more experience on this forum than you will find anywhere. You will also find that 99% of the folks really want to help.
So if you want why not start over with a introduction and a description of your Moho. You have a lot of very expensive repairs ahead of you and this forum can help you get them done correctly and cheaper than you might think.
Heck give it a shot.

[Mr. Hipster]

Those who are concerned about 'responsibility' would do well to preform their own work.

[Hikerdogs]

Originally Posted by jesilvas

That's pretty interesting Hiker.

Was the first area of testing on equipment that ran at a certain RPM constantly and never varied? Basically, very few variables?

Essentially what I've gathered is this: The symptoms for bearing failure is it laying on the ground.

The equipment did have far fewer variables than those encountered by a motorhome. However they did go through heating and cooling cycles, variable speeds depending on loading, and regular wash downs with 140* water and caustic cleaners. The "normal" runtime cycles were between 12 and 96 continuous hours.

[cmckenzie]

Sorry to hear about your bearing failure.
This is a lesson for everyone who owns and operates a diesel or gas engine RV.
i hate to say it but this is part of a pretrip inspection. getting in the engine compartment and checking fan belts,hoses and yes reaching in and grabbing the fan (when engine is off and batteries are disconnected)

your checking the fan for movement or looseness and if any fan blades are cracked or missing.
A pretrip inspection is something that everyone should always do before going on any trip.This could save your life or someone else's life. Not to mention your pocket book. It's always cheaper to find problems at home than at the mercy of some unknown company while your on the road.
Everyone should have an emergency tow package( Good Sam or AAA) it will pay for it's self the first time you need it. You should never leave home with out it
Pretrip inspection is not just the engine, but brakes, driveline, rear end, front end, suspension and your appliances inside your rig. Oh yes almost forgot your tow vehicle.
happy travels

[Brian W]

Originally Posted by GearGirl

I'm not sure how else to say "experienced RV owners, what are some symptoms of fan bearing failure?"

I'm asking for symptoms of Fan Bearing Failure in a diesel pusher. I'm not asking for opinions. And I'm not going to play to some bitter, cynical, misogynistic jerk.

Either reasonable people can provide simple anecdotal experience for me to note, or they can simply move to the next post. I get the distinct feeling some posters get off on giving people as much grief as possible. Pathetic.

And I hate when people use a derogatory term for a mechanic or technician. My technicians HATE when someone calls them "grease monkey". Does this quote look familiar?

"So after logging seven hours on the phone earlier today, I've got 2 grease monkeys telling me it's the fan clutch"