GTP Tranny Noise, Need Help

**GTPGP98** · 03-18-2008

I am not sure what the problem is, that is why I'm here. I believe that my tranny is whining. I just replaced both CV axles and have had both the left and right wheel bearings replaced, but the noise is still there. I think that it is coming from the right side of the tranny. I was wondering if there is much of a possibility of the differential bearing going out? I can move the CV shaft forwards and backwards about 3/16 of an inch, not sure if this is common or not.

**SyntheticShield** · 03-18-2008

A little play in the CV shaft is normal. As for the whine, I'll defer to trannyman and his input as he is far better qualified to answer that than I am.

**Trannyman95** · 03-19-2008

The whine noise can stem to numorous areas of the transmission and there are a few very common ones. I need to know when exactly this noise is present.... Does it make noise sitting still in Park? Neutral? In gear NOT moving? Stalling up the engine in gear not moving? Only when moving? Only in certain gears or speed? The more info I have the easier it is to pinpoint your concern. I have often heard an idler pulley bearing make a noise that distinctly says trans, but is not and using a stethoscope to rule that out helps so you can listen to all of the accessories on the front of the engine or even put it on the trans itself if it does make noise with the car sitting still. An easy test is simply to remove the engine belt/belts if supercharged and see if the noise is still present. If you can answer the above questions as to when this noise occurs I can help out further

**GTPGP98** · 03-19-2008

Thanks for the response guys. The noise is not present when it is in Park or Neutral, but is constantly present throughout speeds from 5-75 MPH, I am sure that it is present at higher speeds but that is above our speed limit here. I just replaced all of the idler pulleys last summer, but I will remove the belts today and try that just to rule those out. What are the common areas of the tranmission that cause noise?

**webracin** · 03-19-2008

This is from trannyman's website...

Loud Whining, changes with engine speed:
This is another common occurance in this transmission and has a lot of different possibilities. There are a number of different bearings that can fail inside the transmission and each one will dictate when the noise is happening. There is a thrust bearing inside the torque converter that can also make a whining noise and is loudest under a heavy load. Generally that bearing will get louder each time the transmission shifts into a higher gear and the converter has to work harder and puts more stress on it. It wont make noise at idle or in neutral unless the entire torque converter is in very bad condition and has lots of metal in it. The most common bearing whine noises comes from the roller bearings that support the drive and driven sprockets which the drive chain rides on. They will make noise any time except sitting still in any gear, that is because nothing inside the transmission is spinning at this time. In park and neutral they do spin and when the noise is most visable. There are quite a few other bearings inside the trans but these are the common ones found bad.

You can read more about the other problems seen with the trans at his website:

4T65E Transmission Info

webracin

**GTPGP98** · 03-19-2008

The problem is not with any of the idler pulleys.
The noise does not seem to get any louder when the transmission shifts into a higher gear so I don't think that it is coming from the torque converter.

**Trannyman95** · 03-19-2008

Does the noise change pitch with road speed OR engine rpm? Turning left or right slightly have any effect on it?

**vermsta** · 03-19-2008

I always say it doesn't hurt to do a tranny service. A constant bearing noise is generally going to show up in the pan, and it doesn't hurt to break the filter open if you see nothing in their. You are usually going to see signs of failure in the pan on a 4t65e in the pan if you have a bearing failure. I have had pump bearings go bad and show no signs of failure, But I'm yet to see this happen on a 4t65 yet. Can you make the noise happen with the car in drive foot on the brake and e brake on and you rev it up to do a stall test? Don't do this for more than 10 seconds though.

**GTPGP98** · 03-20-2008

I have tried a stall test and the noise is not present.
The pitch of the noise may get a little more quiet at 75 MPH compared to 20-40 MPH, but I think that the road noise is starting to cover it up. And it doesn't make any difference if I turn left or right it sounds the same. The noise reminds me of the sound of a bad tire, but I know that is not the problem because I rotated my tires recently.

**Trannyman95** · 03-20-2008

As I mentioned above does your noise change pitch with engine rpm or gradually go up with vehicle speed? Does the tone stay the exact same and have a low pitched humming/droan to it? When you replaced the wheel bearings were they new or used?

**GTPGP98** · 03-20-2008

The pitch of the noise stays the same, it is hard to explain with words but as the vehicle speed increases the noise cycles faster, and it is a low pitch sound. The wheel bearings were new.

**GTPGP98** · 03-28-2008

The noise turned out to be a wheel bearing going out. I wouldn't have thought that that was the problem since I replaced them recently, but at least it wasn't the transmission.