After about 4500-5000 miles of towing between 8500# and 15k#, My truck is starting to make a strange "whining" noise, that is only there at certain RPMs and under a little throttle. It comes and goes... Hard to descibe. I don't remember it being there before. Thing is it does it when in T/H, so I'm not sure if it's the TC or maybe the pump (Assuming it's the Allison). Anyone have any ideas (based on my poor description)?

Anybody? The sound is kinda like a moan... Hard to descibe, but it wasn't there a month ago...

When the fluid is hot (after a long drive), my P/S makes just such a noise. I first thought it was the pump in the transmission. I don't believe that there is a P/S fluid cooler, and it gets real hot, as it does not do it cold.

When the fluid is hot (after a long drive), my P/S makes just such a noise. I first thought it was the pump in the transmission. I don't believe that there is a P/S fluid cooler, and it gets real hot, as it does not do it cold.

Thing is mine does it right from the get-go, while applying power at certain speeds.

I think whining noises from the Ally are very rare. I have not heard one yet no matter how bad the damage was inside the trans. I too have a p/s whine when fluid gets hot.
mike

Is it possible for the P/S to whine like that if it's not hot? The "whine" is there even after the truck has sat overnight, and only when in gear.

The reason I was thinking it was something to do with the transmission (possibly TC) is this noise didn't apear until my last 1100mi trip towing 15K#, and I have heard similar (but much louder) sounds from Ford transmissions.

It is possible for the ps to whine when cold. See if noise changes when steering wheel is turned slowly lock to lock. Mine does.
mike

Ok... just went out and checked it out more... At idle, there is no noise. It appears around 2000~2100 RPM's, in Park and Neutral (as well as when I'm going down the road and accellerating). Moving the wheel didn't make a difference.

Is it normal for the engine to only go to about 2200 RPMs in Neutral and Park?

Yes, there's a limit to how high it will rev in neutral. Is the whine any louder if you do it in Drive?

It doesn't seem any louder in drive. Maybe it is the PS pump even though it does it cold too...

On another note, there is another noise that I can't figure out for the life of me. I think the best I can describe it is kinda a grinding sound, there isn't much of a pattern to it except it SEEMS to occur around shifts (either before or after), but not all the time.

My car ('95 Merc Cougar/2002 PI 4.6L/'99 4R70W) has been making almost the exact same sound for a while, and I haven't figured that one out either. The one thing I've noticed on my car is if I happen to brake or be braking at the same time, braking seems "amplified". I've had the entire front end of my car apart, and can't find ANYTHING binding in any way. The only thing I can think of is transmission, either a clutch pack or the TC.

Now with the truck making pretty much the same sound, I don't know...