Hello and thanks in advance for everyones help! My 2000 Blazer transmission has started to get a humming sound in it. I've checked the differential, wheel bearings, brakes, u-joints, and none of this has solved the problem. This is where I'm really stumped. The humming is not RPM related at all. It only changes with the speed of the vehicle. While cruising at 30 or so, I'll stomp the gas for a second and let off really quick, but the noise stays constant. It still shifts and drives perfectly. The sound don't change when I press the brakes, but it gets louder (cant feel it, just hear it) the closer you are to coming to a stop. I changed both u-joints and the sound didn't change at all. It sounds just like a bad u-joint (without the bad vibration), but I'm sure its coming from the transmission. I added 6 oz. (1/2 of the bottle) of lucas transmission treatment, and that didn't help or hurt anything. I've thought about changing the fluid and filter, but have heard it can harm the seals internally when you do that, so I haven't done it yet. I also noticed a very small amount of play in the tailshaft where the slip-yoke goes into the tranny. This is up and down play, not rotational. I've read there is a bushing in the tailshaft housing that the tailshaft rides on and could be bad, but I want to know what's actually wrong before I pull apart the tailshaft housing. I've never heard what a failing pump or torque converter sounds like. And this is automatic transmission. I've also check all the wiring was plugged in good and had autozone scan for any trouble codes, and there were none. Sorry if I've forgot to include something, Oh this is 2WD so no transfer case. Any possible things I might have overlooked are welcome! Thanks again!
Chevy Blazer 4L60E Humming?
You said you checked the wheel bearings, BUT were they fully packed with bearing grease when you put them back in?
You forgot to tell us how many miles on the Blazer and has it ever been used for OFF ROAD use?
