4th Gear Roaring Noise

[dcountiss]

I have a 2000 Tahoe, 5.3L with the infamous 4L60E transmission. On the way home today, I started hearing a roar from the drivetrain, couldn't tell the exact location, but guessing the transmission. It was only doing it in 4th gear (OD), no other gears had strange noise present. Any help on this would be appreciated.

[MT-2500]

Originally Posted by dcountiss

I have a 2000 Tahoe, 5.3L with the infamous 4L60E transmission. On the way home today, I started hearing a roar from the drivetrain, couldn't tell the exact location, but guessing the transmission. It was only doing it in 4th gear (OD), no other gears had strange noise present. Any help on this would be appreciated.

Try OD off or in 3 gear and see if you can pick up any of the noise at same MPH it is doing it in OD.
Does it do it on coast or pull or steady speed?

[dcountiss]

Originally Posted by MT-2500

Try OD off or in 3 gear and see if you can pick up any of the noise at same MPH it is doing it in OD.
Does it do it on coast or pull or steady speed?

The only time that I hear it is after it shifts into OD, steady speed or slight accelleration. Does not happen in 3rd or in tow/haul. If the gear selector is in the OD position, it does not do it under hard accelleration, just starts when the actual OD gear kicks in.

[MT-2500]

In OD the planetary gears are running.
In 3 gear the transmission is locked solid all the way threw.
Usually OD noise is planetary Gear noise.
If high mileage may be time for rebuild or another transmission.

[dcountiss]

Originally Posted by MT-2500

In OD the planetary gears are running.
In 3 gear the transmission is locked solid all the way threw.
Usually OD noise is planetary Gear noise.
If high mileage may be time for rebuild or another transmission.

That's what I was afraid it was. As far as mileage, turned over 300K about a month ago. If I have to rebuild or replace the tranny now, I guess that I have gotten my money's worth out of the original.

[j cAT]

Originally Posted by dcountiss

That's what I was afraid it was. As far as mileage, turned over 300K about a month ago. If I have to rebuild or replace the tranny now, I guess that I have gotten my money's worth out of the original.

that amount of use with failure is a good info..

[masapell]

Originally Posted by dcountiss

That's what I was afraid it was. As far as mileage, turned over 300K about a month ago. If I have to rebuild or replace the tranny now, I guess that I have gotten my money's worth out of the original.

Yeah, I would definitely agree with that!!

[dcountiss]

Originally Posted by masapell

Yeah, I would definitely agree with that!!

OK, one more observation about the noise - It only happens when the transmission has shifted into fourth gear, and then only if you are holding at a steady speed. Absolutely no strange noise if you are accelerating or let off and coast. Still shifts smooth in all gears.

[masapell]

As was said earlier, you have definitely done well by getting that much mileage out of the tranny. So, I believe the next order of business is to take it to a reputable transmission shop to have them listen to it "real time" and diagnose from there. The shop would also be able to discount any other sources of the roar and then tell you a plan of action. When it comes to the transmission, I feel it is better to let the experts figure that one out. Yeah, it will cost more, but at least you won't be drawing at straws trying to figure it out. When you do get it figured out, please let us know.

Sincerely,
Matt

[cramer_77]

somebody quote me if im wrong but when i went to school they told me that OD was just your converter and makes sense cause when it shifts to OD that would be your converter locking up with the rest of the trans. Reason being you don't hear it on accel or decel is because your converter is not locked solid on accel and decel is cause as soon as you let off the gas is automatically unlocks the converter, i know my hd's trans comes out of OD if i barely let off the gas and get back on it, then again thats a 4L80E. does it shudder or anything when it shifts to OD?

[MT-2500]

Originally Posted by cramer_77

somebody quote me if im wrong but when i went to school they told me that OD was just your converter and makes sense cause when it shifts to OD that would be your converter locking up with the rest of the trans. Reason being you don't hear it on accel or decel is because your converter is not locked solid on accel and decel is cause as soon as you let off the gas is automatically unlocks the converter, i know my hd's trans comes out of OD if i barely let off the gas and get back on it, then again thats a 4L80E. does it shudder or anything when it shifts to OD?

Power goes threw convertor in any gear.
1 and 2 and reverse and OD power runs threw the plantary gears.
In OD them plantary gears are working overtime.

[scooterman2008]

change outer cover and 4th apply piston seal and your noise will stop.