th400 trans whining noise

[kennyd]

any trans. guys out here ,
trans was working fine , then it started making a whining noise , so i thought it was the front pump . i took a different th400 and had a trans shop go thru it , got it back instaled it and a new converter . fired it up ... same noise . why ?
new trans
new converter
new fly wheel ( because it was a little worn from the starter )

list of things we tried to fix it .

by-passed the cooler
over filled the trans ( to see if the dipstick was wrong )
unhooked the converter and started the motor , noise gone
took the trans out again to check the front pump , re-phased the converter and spaced it out only 1/4 of a inch from the flywheel .

ideas ?

[HRBS]

Sounds like a worn or warped input shaft.
Considering you unbolted the convertor and the noise stopped.
Other than the sprag or convertor itself (which you said you changed to a new one), the input shaft is the only thing that would spin while in PRN or D.
Check the shaft or the bearings it rides on.
Sometimes they wear prematurely and dont lubricate the shafts the way they are intended to.
Other than that, I'm stumped.

[kennyd]

Sounds like a worn or warped input shaft.
Considering you unbolted the convertor and the noise stopped.
Other than the sprag or convertor itself (which you said you changed to a new one), the input shaft is the only thing that would spin while in PRN or D.
Check the shaft or the bearings it rides on.
Sometimes they wear prematurely and dont lubricate the shafts the way they are intended to.
Other than that, I'm stumped.


good thoughts , but 2 different transmissions. so the warped input shaft would not be the same in both .

the only part that is the same in both is the , pickup tube and pan , maybe the pickup is sucking to the pan ?

[HRBS]

Oh.... I thought it was "rebuilt". i just re-read the original post.
I'd try a deep style pan just for the heck of it.
Your right, maybe the pick up is too close and the sound is a fluid "suck /whistle" like an old lady sippin tea.

Stupid question but what makes you think its the trans and not the engine?

Other than that one time you unbolted the convertor did it ever not make a whine ?

One other thought.... what size convertor are you running ?
I once tried to fit a 12" convertor on a TH400 that had an ultra bell on it and it was so tight that if i tried turning the engine over it would've scraped the convertor housing.

Also what size flex plate ?
And.... sorry Kenny I have to ask.... is it on reverse (inside out) ?
Sometimes its the stupid easy things we do or forget that end up being the issue. God knows I've been there !

[kennyd]

it has a deep pan on it , i am going to try a stock one .

i have had the trans out of the car and started the motor , no noise .

10in converter , 1 neal chance and 1 tci converter

yes i checked to see if the flywheel was on wrong , it's correct .

??????

any other ideas

kenny

[HRBS]

I checked on this site and found this thread..... they talk about the filter being clogged or of poor quality. Definetly sounds liek a fluid issue.

http://www.hotrodders.com/forum/th-400-whirring-noise-med-rpms-86759.html

Since its all new except the oil pick up and tube (?), I'd also check the O-ring or the pick up itself.

Below, I attached some additional service info I found. Even though some of it doesnt apply, I still attached all of it just for reference.
Let me know what you come up with.

According to the troubleshooting table, if the noise is present while the trans is in park, neutral, and all drive ranges, it could be front pump cavitation caused by low oil level, plugged or restricted filter, wrong filter, intake "O" ring damaged, intake pipe split, water in oil, pump to case gasket problem. The pump assembly could also have a problem like damaged gears, driven gear assembly installed in reverse, orifice cup plug in pressure regulator damaged or missing, and seal rings damaged or worn. There might be a problem with the torque converter like loose bolts, damaged internal converter parts, or a cracked flex plate.

If the transmission is only noisy when in gear (not park or neutral) then you may have a problem with one of the planetary gear sets. If the noise only happens when accelerating, check the transmission cooler lines for contact with the chassis or loose or broken mounts. A squeal at low vehicle speed would indicate a speedometer driven gear shaft seal problem. If the driven gear appears twisted, check for the presence of engine coolant in the oil and check the trans cooler for leaks.

[BRIAN]

Had a problem with pick up in a deep pan. I have been told there are more than one type of filter. If you overfilled it would blow out vent with correct pressure??

Anyway tranny guy welded small strip ofd metal to act as sort of a spring. When pan is installed it would push filter up to proper height rather than it dropping in pan. Make sure old o ring is removed.

I also went through (Lokar) dipstick possibly not reading correctly but it does. I have been told you can go as deep as you want and it will still read up to the correct orig level. Hatch pattern should be near top of valvebody.

No tranny expert but forced to learn from problems.

[HRBS]

Kenny.... what ever happened with this ?
I am curious !

[kennyd]

here is what it was .
the trans pick-up tube in this th400 was only used 61-64 . it is the only pick up that has a flat flange on the pick-up like a oil pick-up .
when i changed the flywheel i used a jack and a 2x4 to hold the trans and it pushed the pan up 1/4 of a inch , with this pick up and a steff's pan that has a flat bottom , it was layin flat on the bottom of the pan causing it to starve the trans .
this would not have done this on a ribbed factory pan .because the ribs would have let it get fluid .
so to fix it i changed the filter and pick-up to the later style .

[HRBS]

the stupid little things always get you !
thanks.... glad you found it and it worked out !