6 speed trans noise
 

I have read many posts about this but I wan't to ask anyhow. Just changed the fluid in the transmission two weeks ago with Pensoil synchromesh and now I have noticed what I would call gear lash noise.It may have made this noise before the oil change and I just didn't notice it.After all I have only owned the truck for about 3 months and still getting use to new noises. It doesn't do it under load or coast but when the trans is turning the same RPM as the motor it's like I am hearing the gears set up a harmonic vibration. No grinding during shifting or any other problems. I know the gears are pretty big in there so is this common noise? Just bought a quart of Lucas full synthetic additive to pull the shifter cover and add in the top thinking this may help. What do you guys think and do any of you experience what I am talking about? Thanks

I think this is normal. Put about 200K miles on my 6 speed and it has been noisy the whole time. If I lug it down in 1st. gear it really clatters. Hope this is the noise that you are talking about.

kennys does yours make this noise in other gears too. like say when not really under load per say but when the trans reaches the same speed as the motor coasting. Kinda like the chatter you hear from a rear end thats set up to loose. Mine seems easier to hear in 3rd 4th.

Mine is quite. On the tranny it says to use a special Texaco oil only. I switched it to Amsoil. I originally put in one type, then the next week Amsoil came out with a newer product. So I flushed it by switching to the new oil. Now it sounds great and works great!

Did you add any additives to the oil originally or have you yet? I would not put in just any kind of oil. Make sure it is the best. Besides, if you have to replace what oil is in there you can concider that an exellent flush!

Mine has quite a bit of noise in like 3rd and 4th pulling hard at lower RPMs. Been that way since new. Also it it hard to get into Reverse once in a while. Maybe a fluid change is in order. I have Conoco sythetic gear oil for the Kenworth in the shop that I am going to put in the differentials, but I don't think it's the proper lube for the tranny. Do I still need to put friction modifier in the sythetic for the limited slip?

Have not noticed any noise in mine except in first gear and in neutral. If I shut the engine off with it idling in neutral, it has a lot of backlash. Just figured that it was a big, heavy duty transmission and was normal.

Mine is quiet. I read your post a few days ago and tried to remember to listen to it. I changed lube to Redline MTL a while back and it shifts smoother, but is still hard to reverse most times. Other times it goes right in. My stock 'lifetime" fluid was past its lifetime at 58K. I added an extra quart to get lube to the rear bearing as I heard this helped cool things down a bit.

Now I have noticed a noise coming from the trans while idle and in neutral but when I push in on the clutch the sound goes away. a throw out bearing will almost always make noise if bad when depressed,so thats not it. Maybe it's a pilot bearing or input bearing. Has anyone experienced this noise and if so what is it? I would like to have a general idea of what it could be before I pull that big honkin chunck of steel out of there. Or is this normal and just leave it alone?