SUCKING NOISE WHEN TRANMISSION SHIFTS WHEN AC IS TURNED ON

[RICK SUSA]

HI, MT NAME IS RICK SUSA WOULD LIKE TO SAY TO EVERYBODY.MY COACH IS A 2004 GEORGIE BOY LANDU W-2O ....WORKHORSE ALLISON-1000. TURNED ON AC WHEN DRIVING AND I GET A SUCKING NOISE FROM FRONT OF COACH WHEN TRANSMISSION IS SHIFTING.THIS IS ODD NOISE NOISE THAT I NEVER HEARD BEFORE.COULD I HAVE A PROBLEM WITH AC COMPRESSOR.THIS IS A OFF AND ON THING DO I HAVE A PROMBLEM???ALSO IF THERE WAS A PROBLEM WITH TRANNY SHIFTING WOULD A GET A WARNING LIGHT. CAN ANYBODY RELATE TO THIS PROBLEM???? SHE HAS ABOUT 5,OOO MILES ON HER ,AND SHE BEEN SITTING FOR AWHILE.......THANKS NE MEMBER....rick

[RICK SUSA]

HI, MT NAME IS RICK SUSA WOULD LIKE TO SAY TO EVERYBODY.MY COACH IS A 2004 GEORGIE BOY LANDU W-2O ....WORKHORSE ALLISON-1000. TURNED ON AC WHEN DRIVING AND I GET A SUCKING NOISE FROM FRONT OF COACH WHEN TRANSMISSION IS SHIFTING.THIS IS ODD NOISE NOISE THAT I NEVER HEARD BEFORE.COULD I HAVE A PROBLEM WITH AC COMPRESSOR.THIS IS A OFF AND ON THING DO I HAVE A PROMBLEM???ALSO IF THERE WAS A PROBLEM WITH TRANNY SHIFTING WOULD A GET A WARNING LIGHT. CAN ANYBODY RELATE TO THIS PROBLEM???? SHE HAS ABOUT 5,OOO MILES ON HER ,AND SHE BEEN SITTING FOR AWHILE.......THANKS NE MEMBER....rick

[DriVer]

Rick, Welcome to iRV2.com.

No I can't say that I have but try to get the motorhome out on the troad and run it for a few hundred miles. If its been sitting for a long time that might be the best thing for it. If you continue to have problems, here are 2 service centers close to where you live.

The Turning Wheel RV Center
1905 S. Frontage Road Plant City, FL 33566
(813)752-6814

Turning Wheel is right off the I-4.

Bill Heard Chevrolet Inc.
2002 N. Frontage Road Plant City, FL 33563
(813)359-5450

[RICK SUSA]

will any indicator light come on if shifting was incorrect. or if there was a problem with the transmission. still can not understand this only makes sucking noise when ac is turned on.runs well with and no noise when ac is off. thanks for your reponse............rick

[DriVer]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RICK SUSA:
will any indicator light come on if shifting was incorrect. or if there was a problem with the transmission. </div></BLOCKQUOTE>In your owner's manual you will no doubt see the Range Inhibit Lamp on the IP. If there is a problem with the Allison and it's not shifting properly, that light will come on.

When the A/C is tuned on a Workhorse the auxilliary cooling fans will spin up. This is the only extra sound that I am aware of.

A vacuum (sucking) sounding noise would be quite unusual.

[RICK SUSA]

COULD THERE BE A PROBLEM WITH AC COMPRESSOR,OR COULD BELT BE SLIPPING. MAYBE COMBO.SOUNDS LIKE IF TRANSMISSION WAS SHIFTING INCORRECT INDICATOR WILL HOPELY COME ON. D RIVER, HEARD OF SOLONIOD IN ALLISON STICKING. IS THIS POSSIBLE?????? JUST TRYING TO EASE MY MIND.............RICK

[Gary the Wombat]

Hi Rick. I'm sorry but I can't help you with your problem. However I have a request--please do not type in all caps. It is hard to read and some people see it as the internet equivilent to shouting.

P.S. The only sucking noise I get with my RV is the sound of money being sucked from my wallet (sorry, but I couldn't resist.)

[Kazoo Tom]

Rick, you said you hear the noise from the front, not from the transmission area. Does the airflow change from the a/c vents when the shifting happens? Could be you have a vacuum leak in the vent system that is moving some of the gates when the transmission is shifting (changing rpm's).

[RV Wizard]

I too think it is the air dampers controlled by vaccum. You may have a bad vaccum line or damper valve. I do not think it is the transmission itself. Let us know what you find.

[RICK SUSA]

hi mike, thanks for the input.can you steer me in the general direction. to locate the vaccum line or damper valve.question to ease my mind would the indicator light come if shifting were incorrect,in any gear when shifting. driver noted light would come on.? what about over drive.--------thanks for all your help*********rick

[RICK SUSA]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kazoo Tom:
Rick, you said you hear the noise from the front, not from the transmission area. Does the airflow change from the a/c vents when the shifting happens? Could be you have a vacuum leak in the vent system that is moving some of the gates when the transmission is shifting (changing rpm's). </div></BLOCKQUOTE> hi tom , sounds possible.can you steer me general direction of gates.or vaccum line/s or damper valve/s .............thanks for your input........rick

[Kazoo Tom]

I have found that one of the vacuum give aways is that the air flow from the vents will change if the vacuum is bad or leaking. Example, the air flow will shift to the defroster vent under load instead of the dash vent. The sound could also be an engine vacuum line. There are several connecting points for the engine vacuum, problems frequently found by trial and error. They can sometimes be a bear to hunt down.

As DriVer suggested, I might seek out a Workhorse service facility to help identify and locate the problem.

[RV Wizard]

One way to help find a vaccumm leak is to have engine running and spray the suspected area with a flamable lubricant or starting fluid. If there is a leak there the engine will pick up in RPM's. Try to keep the spay to a minimum and out of the air intake area. Good luck and let us know what you find.

[Tom&Marie]

Rick, If the noise you are referring to also could sound like a pump or fan that disengages audibly when you reach a cruising speed when the ac is on the problem is the ac compressor.I have a 2005 HR with a W-22 8.1 with 6500 miles. As you accelerate turn off the ac and the noise will stop. WH replaced the ac compressor under warranty. Tom 561-722-9303