yakerat

Hey guys, wondering if anyone has a similar problem. I have been experiencing this noise for at least 2 years now. I thought it was originally related to my failing third member, but it has since been rebuilt and the sound is still there. The sound is barely noticeable in any gear other than 5th, but once i shift into 5th it gets pretty loud. The humming noise changes frequency with RPM and goes away in neutral. It is difficult to tell, but it seems like it is coming from behind the passenger side of the dash. I have done many things to attempt to resolve this problem.

I recently had my third member rebuilt, and it is completely silent now. I just had a doug thorley tri-y header installed which does not leak at all! I patched all holes in firewall. Recently have installed an 8.1 sound system with 2 amps and a capacitor. Pretty sure sound does not come through speakers. Replaced the fan clutch with new aisin part. Wheel bearings are in good shape, as well as brakes all around. Dynamat around the entire cab and new carpet.

I am honestly out of ideas and I was wondering if anyone has this problem or has fixed this problem! Thanks SO much for any input!

DixieThunder

I have a similar thing going on, has been that way since I bought the truck. Not sure what it is but definitely subscribed to see what pops up. Sorry I know this doesn't help you out just wanted to let you know that you're not alone.

yakerat

I know someone has fixed this, you guys always come up with great advice!!!

lastname_firstname

sounds like it could be your heater fan whirring because of a bad ground somewhere...Im not sure about toyotas because i havent been through my dash yet, but with volkswagens, even when the fan is off it still draws current and when i had a bad ground it would make the same kind of changing-frequency sound with rpms

maybe not stereo gremlins, but check the grounds for your lighting system.

greygoose

Sounds like the bearings on the counter ( secondary) shaft on transmission. Mine had similar noise also in 3rd and louder in 5th. Humming whirling noise got louder with time. Drove it for a year then pulled it and had it rebuilt. Noise went away. My buddy who rebuilt it and is a toyota tech said that was what it was. The only gear it was quiet was 4th because the counter shaft is locked and power transfers straight through the main shaft on the tranny.