Noise like a buzzer or pump when 6 speed allison winds up to shift point

[bullydogs1]

We just returned from Florida--It was our first long trip in the Coach during 80 degree plus weather...The fans would whir from time to time but that's Ok of course...What I noticed is that when the transmission would be winding up the RPM's is that there would be a buzzing sound like a pump or something and then when the shift to the next gear would drop the RPM the noise would stop...happens in all gears during hot weather---is there another pump or fan that kicks in when the trans needs to be cooled..we were traveling up some hills but did not have our toad.

Thanks

[bullydogs1]

We just returned from Florida--It was our first long trip in the Coach during 80 degree plus weather...The fans would whir from time to time but that's Ok of course...What I noticed is that when the transmission would be winding up the RPM's is that there would be a buzzing sound like a pump or something and then when the shift to the next gear would drop the RPM the noise would stop...happens in all gears during hot weather---is there another pump or fan that kicks in when the trans needs to be cooled..we were traveling up some hills but did not have our toad.

Thanks

[JCM]

Check your low oil pressure warning buzzer. You should see a notice in the bottom of the display as well. I noticed this when using a FRAM oil filter and high rpm. I went back toa GM oil filter and had no further problem.
Just a posibility.

[bullydogs1]

This is a W22 and I looked at panel when it was happening..no warning lights--no nothing...just a pump like whirring/buzzing sound..everything is normal..but the sound drives me crazy.

[M&EM]

Check your belt driven engine fan to see if it is rubbing on the shroud. This has been a problem for some who have posted here. The fix has been as simple as securing the bottom of the shroud with a sheet metal screw and as severe as having to have fan and/or shroud replaced.

Other sources of buzzing might be PS pump, A/C compressor, exhaust leak etc.

[E Z Livin]

Stuart, not sure what sound you are describing.
My first outing two years ago was to Florida.
Came off Interstate on a secondary road and the fans came on and I thought the transmission was slipping. The load roar would go to a lesser roar as the gears changed higher.
Told my Bother-In-Law about it and he told me to refer to the manual and it was fan noise.
Well, Workhorse has a statement in the book that states not to confuse the fan noise with a slipping transmission.
Mine will come on when you slow down a lot, climb hills and other times.
Is your noise you hear only when the fans are running? If so, you might not have a problem.
If this noise is present when the fans are not running, then I would be concerned.

[John-D]

One of these days I'm going to invite someone (ALAN are you listening) to ride shotgun

The 8.1/Allison combo makes a whole bunch of sounds I can not identivfy. None trip an "ALARM" in my mind though, they all sound normal, but there are a lot of them.

At "Speed" it rides nice now and no strange sounds.