Whine, squeal, howl from basement air

[JucenBrudi]

Hi Gang,

It has been HOT!

We have a Coleman-Mach basement unit on our 2004 Adventurer. It seems to be cooling quite well but at the same time it has started to make an unpleasant noise, whine, squeel, or howl. Often, it runs an hour or two and the noise stops and it keeps on cooling nicely and the noise may start up again. It seems to be worsening.

A fellow camper suggested it was a minor matter, probably the fan rubbing on something. A mechanic, not an A/C guy, said it sounded like a bearing going out on the fan.

My wife doesn't want to run the A/C because "we may ruin it." I'm thinking it is not the A/C and if it is a bearing and goes bad, no big deal, it needs replacement anyway. I could stop using the A/C when the fan stops.

Three questions:

What do you think of continuing to use the A/C and ignoring the noise?

Is there anything I might be able to do before taking it for repairs?

Does anybody recognize the problem?

Thanks
Bruce

[NeilV]

Bruce,

There are bearings on the fan shaft that need to be lubricated on that unit. If left go too long you may be looking at also replacing the fan motor and blower wheel if they get damaged as the vibration that comes with the squeel could crack the blower wheel or put enough drag on the motor to burn it out.

[Harry B]

It's probably the fan squirrel cage that is developing slack where the blades are joint to the front and back plates. This will cause that type of noise. It's not going to cause any harm to continue running it but if you want the noise to stop the squirrel cage will have to be replaced. RVP now sells an all plastic unit that won't develop this problem again. It's not an uncommon problem.

[AFChap]

Twice (2005 & 2006) I have had my unit pulled for what a service tech said was blower fan noise ...once it was "needs lubrication" and once "blower run-out adjustment. In the first case, they told me the remaining squeal on startup was "normal startup noise." I knew better, but let them snow me..." In the first case, the squeal/squall got worse until it was continual. In the second case, the noise returned n a couple of weeks and gradually got worse. Since we are fulltimers we don't often get to take a failed repair back to the same place. In BOTH cases we had to take the unit in for repair within about two months or so. And in BOTH cases the real problem was the blower motor ...both the inside and outside motors have been replaced on ours.

One thing I learned was NEVER take the unit to a service facility not listed on the RVP website, not even if they are a large Winnie dealership. The last tech who worked on it at Flint Hills RV just East of Wichita KS was awesome ...he had the unit out (with wiring still attached so it was easy to test run and diagnose) and diagnosed far faster than the other places could even begin to get started.

Oh, and in spite of the fact that the oem blower bearings have oil points, RVP says "no service required." Mine runs year-round, and has not been "serviced" in any way for 4 years now ...except for my cleaning cottonwood fluff off the outside coils.

[JucenBrudi]

Originally Posted by NeilV

Bruce,

There are bearings on the fan shaft that need to be lubricated on that unit.

The unit appears to me to be fairly well sealed and maintenance instructions don't mention any needed lubrication. It looks like a major effort to work on anything on that unit.

Maybe I don't understand your reply. Thanks, though

Bruce

[JucenBrudi]

Originally Posted by Harry B

It's probably the fan squirrel cage It's not going to cause any harm to continue running it but if you want the noise to stop the squirrel cage will have to be replaced. RVP now sells an all plastic unit that won't develop this problem again.

Since I first posted, I have taken the rig to an authorized repair service and they pretty much told me what you have. On your and their advice we plan to ignore the noise (we don't run it often) and schedule the repair at our convenience between outings.

Thanks for your reply. Your and other replies here helped me work more effectively with the mechanic.

Bruce

[JucenBrudi]

Originally Posted by AFChap

in BOTH cases the real problem was the blower motor ..

One thing I learned was NEVER take the unit to a service facility not listed on the RVP website

I'll be sure to mention the blower motor when we take it in. It could make a nice difference in getting it right the first time.

Per your recommendation for a listed facility, I had already scheduled with a facility we've used several times. When your recommendation came in I checked RVP's recommendations and ours was top of the list, so we kept the appointment and will likely use them when it gets to ordering the parts and scheduling the work.

Thanks,
Bruce

[Duner]

Bruce,
Download this troubleshooting guide I made when I repaired mine two yrs ago. Click here: A/C Repair Procedure

It will give you some insight to the problems and the cost for the items I had to replace. Be sure to have them tape up any air leaks in the cold air out duct work. If you haven't touched it, I can just about guarantee you have some dried up tape and leaks at the elbow.

It will sure run a lot quieter with the new plastic squirrel cage. From the symptoms you describe, your metal blower probably has a cracked/loose hub like mine was.

Good luck,
Bill
PS: I hope it doesn't cost you an arm and a leg

[JucenBrudi]

Originally Posted by Duner

Download this troubleshooting guide I made when I repaired mine two yrs ago. Click here: A/C Repair Procedure


PS: I hope it doesn't cost you an arm and a leg

Hi Bill et al.,

Thanks for this post. I found your "A/C Repair Procedure" link yesterday; what a NICE piece of work you have done there. I've shared it with a friend with a fairly recent Adventurer. Our rig is an '04 Adventurer so your photos look like they could be our rig.

Your instructions look so straight forward they have gotten me thinking seriously of doing the work myself. Over the 7 years we've had this rig I've gradually taken on more- and more-"daring" projects. Doing the A/C maintenance-repair would be among the most "daring" for me so far.

Often, I've dared tackle a new project for just this reason, someone here posts clear instructions which reveal just how possible it is.

As for costing an arm and a leg, that's hard to avoid these days. Labor charges here are $109, currently. However, if I follow your instructions successfully there is no doubt I'll save a bundle. Its a bit early to know for sure, but based on a tip on iRV2 a few months ago I spent $6 and repaired our gasoline tank. I estimate that save us well over $2000.00 and a lot of time.

So, thanks again, and keep up the good work.

Bruce

[jdsr]

Originally Posted by JucenBrudi

Hi Bill et al.,

Thanks for this post. I found your "A/C Repair Procedure" link yesterday; what a NICE piece of work you have done there. I've shared it with a friend with a fairly recent Adventurer. Our rig is an '04 Adventurer so your photos look like they could be our rig.

Your instructions look so straight forward they have gotten me thinking seriously of doing the work myself. Over the 7 years we've had this rig I've gradually taken on more- and more-"daring" projects. Doing the A/C maintenance-repair would be among the most "daring" for me so far.

Often, I've dared tackle a new project for just this reason, someone here posts clear instructions which reveal just how possible it is.

As for costing an arm and a leg, that's hard to avoid these days. Labor charges here are $109, currently. However, if I follow your instructions successfully there is no doubt I'll save a bundle. Its a bit early to know for sure, but based on a tip on iRV2 a few months ago I spent $6 and repaired our gasoline tank. I estimate that save us well over $2000.00 and a lot of time.

So, thanks again, and keep up the good work.

Bruce

believe me with Bill's inst you can do the work yourself if your just alittle bit mech inclined. I made 2 copies just in case

[JucenBrudi]

Originally Posted by jdsr

believe me with Bill's inst you can do the work yourself if your just alittle bit mech inclined. I made 2 copies just in case

Well, your encouragement just about seals the deal. I'm now planning to do it myself. I'm not sure when I'll get to it (we're trying to sell Sticks & Bricks), but I'll plan to follow up here at iRV2 with something of my experience. You even moved my wife (Judi of JucenBrudi) to thinking I could probably do it!

Thanks,
Bruce

[JucenBrudi]

Originally Posted by JucenBrudi

Well, your encouragement just about seals the deal. I'm now planning to do it myself.

Good morning gang,

I've done it! I have pulled the unit, opened it up, and started it. I quickly isolated the howl to the outside blower assembly. Oil on the bearing seemed to have no noticeable effect and the fan seems to spin smoothly when the motor is off, suggesting the howl is not coming from the bearing. Moving the fan by hand I can hear a slight rubbing, which may rise to a howl under power, but I'm far from confident about that. I'm suspecting the howl is from a bearing going out in the motor itself. I have the assembly out (that was a bit of a challenge) and expect to have the motor out for a close look later today.

I was surprised to find that the shaft from the bearing back to the fan mount and the far end of the motor are covered in a thick layer of what looks like oily black stuff more like what I'd expect to find in gasoline engine work, not electrical motor stuff. There is no sign of it on the inside blower motor.

For years I had a seeping gasoline leak in the gas tank not too far from the A/C. It is now fixed, but I'm wondering if the A/C could have pulled in enough gasoline fumes to accumulate the dusty/oily stuff. It does not seem to smell obviously of oil or gasoline.

At this point I know which blower assembly is creating the howl, and assume it must come from either a) the bearing at the outside end of the shaft, b) the fan rubbing somewhere, or c) the bearing going out in the motor itself.

Questions: Is there another possibility? and how can I determine which it might be? I hope to order parts tomorrow.

Thanks,
Bruce

[JucenBrudi]

Originally Posted by JucenBrudi

Good morning gang,

I was surprised to find that the shaft from the bearing back to the fan mount and the far end of the motor are covered in a thick layer of what looks like oily black stuff more like what I'd expect to find in gasoline engine work, not electrical motor stuff. There is no sign of it on the inside blower motor.

It does not seem to smell obviously of oil or gasoline.

I'm back at it this morning and have taken a closer look at the black stuff. It does, in fact smell oily when you smear it and smell it up close.

Bruce

[JucenBrudi]

I may have found my problem. I disassembled the noisy blower assembly and did a quick test of the motor, itself, no fan attached. It runs quietly.

The fan shows no sign of rubbing anywhere.

I've cleaned the oily stuff off.

I have inspected the bronze bearing. It has an oil cup and what looks like a bronze bushing that the shaft rides in. I would have expected that the bronze "bushing" should turn freely in the housing, but it doesn't. If so, the bearing is frozen and likely is the source of my problem. If it isn't supposed to turn freely, then I'm quite puzzled about my problem.

I'd relax a bit if I had confirmation of this interpretation and figure all I need to order is a new bearing.

Bruce

[AFChap]

how can I determine which it might be?

Sounds like you have already torn it down further, but here's a very old mechanic trick to isolate a sound, particularly a bad bearing. Get a wooden broomstick, hammer handle, etc long enough to put one end to your ear and the other end on suspected components ...kind of a cheap stethoscope. I learned it from my grandfather, and it has helped me MANY times. When you hit the bad component it will be VERY obvious compared to other areas you listen too.

[Duner]

Originally Posted by JucenBrudi

.......The fan shows no sign of rubbing anywhere.

I've cleaned the oily stuff off.

I have inspected the bronze bearing. It has an oil cup and what looks like a bronze bushing that the shaft rides in. I would have expected that the bronze "bushing" should turn freely in the housing, but it doesn't. If so, the bearing is frozen and likely is the source of my problem. If it isn't supposed to turn freely, then I'm quite puzzled about my problem.

I'd relax a bit if I had confirmation of this interpretation and figure all I need to order is a new bearing.

Bruce

Ok Bruce, I think that you have just about got this thing licked ...just a few comments:

1) the brass bushing does not rotate or turn.... only the motor shaft inside turns. I think you'll find that the shaft has too much slop inside the brass bearing surface. There should be no slop, maybe a couple of thousands of an inch. Just compare the outdoor blower brass bearing to the indoor blower bearing, they are the same part and can be swapped to prove my point. The indoor bearing runs in the ice cold refrigerated air and wears much slower rate and the shaft is a lot shorter so there's less stress. It's real easy to swap the two bearings and test the results.

2) You have to inspect the metal squirrel cage real close to find any problems. On mine the steel hub was slightly loose where it is crimped to the aluminum wheel and would squeal on start up and shut down. It also had a crack in the aluminum hub that made the whole cage howl continuously.

3) I strongly recommend that you replace the metal squirrel cage with the plastic one so you won't be dealing with a future problem even if you think it is ok now. One iRV2 poster said he saw a whole pile of metal squirrel cages at a RVP repair shop ..... they find them defective all the time.

Good Luck,
Bill

[JucenBrudi]

Originally Posted by Duner

Ok Bruce, I think that you have just about got this thing licked

1) the brass bushing does not rotate or turn

2) You have to inspect the metal squirrel cage real close

3) I strongly recommend that you replace the metal squirrel cage

Good morning Bill et al.,

I was hoping I'd hear from you and others following this thread.

Since my last post I have removed the second blower assembly and its bearing and found that the bushing doesn't turn and had pretty much drawn the correct conclusion. I'll swap them out and study the fit, etc. The shaft on the problem assembly shows wear under the bushing, not bad scoring or anything, and it runs smoothly now that the "gunk" has been cleaned out.

Does that mean the motor should be replaced? I guess a test by swapping bearings would answer that question. Swapping is a nice suggestion; it hadn't occurred to me.

I cleaned the fan carefully and didn't notice any thing out of order (except the oily gunk I found on the motor and shaft), but I'll examine the fan closely with your comments in mind. Still, I'm strongly inclined to take your advice and just replace the fan.

Do you have any thoughts about the oily paste I found on both ends of the motor, the shaft, the bearing, and the fan? It was gritty like a paste of fine grit from emory paper. Does it perhaps indicate a problem I should address?

I mentioned to an RVP tech the idea of replacing the bronze bearing with ball bearings. He didn't seem enthused about it, he didn't argue against it, more as if it were over kill. it sounds like a good idea to me, after all, it does appear one of the bronze ones went out and I'd expect the ball bearings to last longer.

Do you still stand by that recommendation? I found the parts you mentioned are available at Grainger's.

One more thing. Perhaps the most infuriating part of this whole process is the huge difficulty removing bolts holding the bearings in place. They look like stainless steel, they have no sign of corrosion, but the heads stripped out quickly. I worked for a long time removing two of the worst. They are unusuable. two more more are bad enough I don't want to use them again.

Do you have a suggestion for a better grade part to replace the lot of them?

Thank you again for the detailed help. It looks like I'm headed for success.

Bruce

[Duner]

Bruce,

Regarding the oily,gritty gunk on the blower shaft....

The the brass bearing is a sintered material that is quite porous and holds a lot of oil when brand new. Over time, and with heat, it's going to weep out and wick all around the nearby surfaces. The basement is so low to the ground and the outdoor blower is sucking dirty air thru the coils so it's going to get very gritty. When the a/c is run while driving down the road, it's exposed to a lot of road grit. Just look under the hood of any toad pulled behind a motorhome......unbelievable amount of large and small grit.

Regarding RVP's comment about changing to ball bearing, if you asked this question to RVP......

What do you think about a novice like me pulling out the blower assembly? You'd get the same kind of response.....hesitation, concern, and a recommendation to let a trained pro do the work. They are not used to having us DTY'ers conferring and relating our experiences.

Regarding the screws, ya I remember they were very tight. You need to have a good matching tip on the phillips screwdriver to get them out clean. You could use a hex head bolt/nut/washer to replace the large botched up screws. Just make sure you get the bearing screws very tight when you put the new ones back, recommend Loctite on the threads. Also the set screw(s) on the squirrel cage need to be real tight too. The new one will have pre-applied Loctite on set screws.

Bill

[JucenBrudi]

Originally Posted by Duner

Bruce,

Regarding the oily,gritty gunk on the blower shaft....

The brass bearing is a sintered material that is quite porous and holds a lot of oil when brand new.

Regarding RVP's comment about changing to ball bearing

Regarding the screws, ya I remember they were very tight. You need to have a good matching tip on the phillips screwdriver to get them out clean.
Bill

Hi Bill et al.,

Very interesting information about the brass bearing. Frankly, I was puzzling how the oil got to the shaft . I'll take it the gunk is normal wear and tear and doesn't indicate some other problem. Perhaps ball bearings are sealed so little or no lubricant would seep out. The illustration shows no oil cap.

The first guy at RVP I talked to was helpful and said he'd sell me the parts. When I called in today I got the recorded message saying "this is for trained technicians." That's a bit off putting, but I'll call anyway and ask my questions and place my order.

In my defense, about the screws, I believe I had a perfect fit. The screw heads just seemed soft. Hex heads promise to fare better. I'll use Loctite.

My current plan:

1) swap the current bearings and do a test run. If the noise moves to the inside blower and does not occur on the outside blower it tells me two things. The bearing was the problem and the motor and shaft are fine with a good bearing so the motor doesn't need to be replaced.

2) order two ball bearings

3) order a new fan

4) put it all back together

5) enjoy not only a quiet A/C, but the pleasure and satisfaction of tackling what, to me, is a major repair project.

I can't thank you enough for making the effort to prepare the photos and instructions and taking time to support me through the project. I look forward to passing along my new knowledge to someone else in need down the line.

Bruce

[JucenBrudi]

Originally Posted by AFChap

kind of a cheap stethoscope.

When you hit the bad component it will be VERY obvious compared to other areas you listen too.

Hi Paul,

Nice tip. I'll be trying it out as I continue troubleshooting. I suspect the technique will prove handy over the years.


Thanks,
Bruce