95 Bronco 5.8L E4OD Transmission Whistle

you need first of all to have the transmission fluid and filter changed

1) to make sure the filter isn't restricted 2) replace the filter-to-pump seal 3) to look for 'identifiable debris' in the pan

sounds like a restricted filter and the pump may be cavitating or sucking air around the filter neck

Also, in addition to chacking out the tranny and transfer case, you may want to make sure it isn't the rear end gear whining as well. I have heard a whistle very similar to the one you describe come from many ford rear ends. Even though it sounds like its coming from up front, the sound can travel and sound like its coming from anywhere. Just a thought, good luck! Erik D. '94 white lightning

I did have a rear end problem a couple of years ago that was fixed under warranty. That noise changed with vehicle speed. This problem seems to be changing with engine speed.

Thanks for all the responses so far. I had the transmission serviced (drain and fill) in June, so I'm hoping it's a filter issue.

Follow-up information. I have an auto-start on this vehicle and this morning, I noticed the whistling noise when I started it up. The whistle was there even with the rig parked...so I think it's definately not the rear end! Any more ideas would be appreciated...could I actually have a clogged/frozen air filter? But why would the sound from inside the vehicle be from underneath?

Thanks again for any replies,

Doug

Is it coming from the transmission itself or from the torque converter area? I've noticed a "whiny whistle" coming from my transmission lately, I changed the filter, which was really just a screen, and same sound is still there. I heard it could be coming from the pump...maybe yours is too?

It's whistleing because it don't know the words. Sorry, I counden't resist :(

While I still haven't found out what this whistling noise actually is, I'm now thinking that it may actually be coming from the engine compartment. Initially I thought that the belt might be loose and screaming, but that doesn't appear to be the case. What else under there could cause that whistling noise? It's pretty loud.

You can eliminate the belt for sure by coating it with something. A shot of belt dressing will tell you pretty quick. Also, the idler pulley can go out prematurely and start a noise.

Spdloader

Maybe a cracked/leaking vacuum line? EGR line or valve?

I'd bet on the smog pump, mine whistles too. I forgot about that because I am used to it. If you can find a belt to go around it, you can listen to see if thats what it is because if the belt isn't around it, it won't make any noise. Thats how mine is. Good luck! Erik D. '94 white lightning

Ok, dumb question time... :/ How much air pressure does a smog pump make?

Alvin in AZ

You can get a couple of psi out of them. They make excellent aquarium air pumps. Mount them on a board, drive them with a small motor and sit it in the basement where you don't have to listen to it. Then run your small tubing upstairs to the fish.