70 road runner 440,727 torque flight,driving home after a 40 min cruise on a less then 300 mile tranny rebuild,goosed it to pass an older gentleman who decided to stop in the middle of road,at the point i heard a loud whinning sound from tranny,sounded like a fan belt,got home,noticed at speed and not accelerating noise gone,but got terrible again at the stop light.Got home,let it cool,fluid perfect,no burnet smell,and full.Start it up all normall,until i put in drive or reverse with foot on brake,back to park or neutral no whinning sound,any thoughts where to begin? or do i need to pull the tranny after only 300 miles,any direction would be appreciated,thank you,

no thoughts?

Sounds exactly what I went thru with my 727 tranny. I heard a loud whinny noise only during certain RPM's of the engine. Its very hard to track down engine noises but I thought it was coming from the tranny. I would put it in gear, hold my foot on the brake while in drive and I heard the noise. Put it back into park and the noise stopped. Then one day noise seemed to be coming from PCV valve. I replaced the PCV valve and my whinny noises went away. Try eliminating the pcv valve while your testing or if you have another laying on the shelve, just try trading it out. Let me know.

thank you,and i did eliminate it,with no change,any other thoughts? wanted to hopefuuly diagnoise,and if it has to be pulled,start pulling,crawling under it now.

Make sure it has enough fluid hot and idling in Neutral. look for foam or air in the fluid.
check your flex plate bolts may have lossened off?

thank you,fluid is good,no foam,and full in neutral,i'm so bummed because i wanted to come home and head out to a show,i hoped to solve this problem,before heading to niagra falls canada(your area)so i'm not worried about it on my vacation

checking flex plate bolts next i'll report back

wonder if the flex plate is cracked?? they will wine if the suck air?
strange??

Had something similar on my 1977 power wagon 440/727, it was almost like a whine, it ended up being the front pump and it burned out the trans in time, had a similar noise in my 2002 superduty diesel and it was also the pump, hope you have better luck.

in the tranny part of my manual says low fluid (sucks air) front pump, malfuntioning valve body or sprag race failour!

It could be pump whining, but I suspect it is the pressure regulator valve doing it.

thanks for replys,flex plate bolts are tight,and visual inspection shows no crack,so it seems i have to pull the tranny

Rather than pulling the tranny which would mean taking it apart blind take the car to a tranny shop & have them drive the car... As mentioned it could be fliud bypassing the pressure regulator causing a resonating buzz/whine... It could be the front pump or it could be the convertor... A guy that has done trannies for a living should be able to pinpoint the noise & & if it's the pressure regulator the trans stays in the car....

thank you Randy,really hoping that your suggestion is the problem hope all is well with you

Sitting at the airport, be in a plant in Jersey tomorrow AM.. Back home mid week, short car cruise & BBQ next Saturday... Not a bad week..

can i test presure regulator? how to find out?

Whining when loaded in gear is usually caused by pump restriction, such as clogged filter, or by a bad torque converter.