Hello-

I have a 440/727 in my truck and recently have a loud whine I suspect coming from the transmission.

For debug, I removed all the drive belts (water pump/alternator/power steering pump).

Whine is loud as soon as started and is continuous.
If I put it in gear the whine is reduce somewhat, back in park and the noise level is back to loud.

It sounds like a pump noise to me.

I dropped the trans pan and the pan was clean. I replaced the filter and installed 5 quarts of fresh ATF+4.

No change in noise.

Wondering if its the torque converter starting to go bad or the pump?

Wondering what to do next for debug?
How to determine if it's the TC, pump, or ?

Thanks for any help!

 

 

Is the fluid level normal? Five quarts doesn't sound correct.

 

maybe check to make sure nothing is rubbing on the flywheel under there... i had that happen in an old truck of mine, very annoying. whisper quiet after lol!

 

Hello-

After looking online, most people said 4-5 quarts for pan drop and filter change, so I went with that and then checked the level in neutral, level is above the full line.....

I did not drain the torque converter...

I am going to disconnect the trans cooler and try to pump out some of the fluid and refill until clear.......and then bypass the cooler.....

Really sounds like a pump noise to me......

I have heard the TC will whine when starting to fail... or maybe it's just the pump.....

I will also readjust the kickdown lever or maybe just disconnect at idle to see if the noise is the same......

Any other thoughts? or tests I should perform?

Thanks for any advise!

 

I actually think your on the right track but needed to ask about the fluid level first.

 

Sounds to me as if the Planetary is gone out in the trans..... Just my 2 cents....
https://www.coperacingtrans.com/?pro...lanetary-gears