'04 6-speed low RPM growl/noise

[KBennett]

I searched for this and could not find anything that directly answers my question:



I can't recall my truck doing this before my trip to Vegas but after I got there I noticed that whenever I shift at a low RPM(less than 2000) and the letoff RPM is about 1300-1400 RPM I get a growling sound from what seems to be the transmission. After the RPM's pass the 1500 mark it goes away. Maybe I just noticed it while driving slowly on the strip? I have not checked the trans level but it only has 2100 miles on it.

 

[Boonieman]

Are you talking about when you're just idling along? Mine does that, as well as all other sticks I've had... particularly if you're in too high a gear. Can you give more details?

 

[KBennett]

More details.........

It does when slowly accelerating from an idle or when I shift it early and accelerate slowly. My last three trucks (2 Nissans and a Toyota) only whined a little and my GTO with a 4-speed Muncie will whine but not make this growling sound. Could it be that I am lugging the engine?

 

[Boonieman]

If you're upshifting at 2000 rpm, I personally wouldn't consider that lugging it. My driveway has a slight grade to it and when I turn in if I pull up it in second gear, no growling. If I go up in third gear I'll hear the transmission complaining a little. Honestly, your's sounds normally to me, at least compared to mine. My Nissan 4X4 had a much quieter (and tinier) transmission. But, it wouldn't pull a tractor and bush hog either.

 

[CATCRACKER]

welcome to a mans transmission! the gears in this transmission are huge! big enough to pull a CAT D3LGP Dozer 17300lbs on a 20GN goose neck at 65mph (GVWR 29300). could your toy do that. these trucks are not like other trucks. these 6spd's are bad MF's

 

[boonsur]

I do think that 13-1400 rpm is lugging. The transmission's fine with it, but I think it's bad for the Cummins. I don't like to squeeze the pedal down unless the rpms' are above 1500, 1800 before I put it down hard. Shifting at about 2200 gets you right back in the 15-1800 range (depending on which gear split you're in).

 

[KBennett]

LUGGING

boonsur I think you're right, I am probably lugging the motor. I will have to learn how to find the right gear for the lower speeds. It just seems odd that a truck with all this torque does not like to run smoothly below 1500.



Oh well, it's a great truck anyway!



Thanks all for the input.

 

[Fast 1]

Check the oil,

Check the oil,

Check the oil,

 

[CSilkowski]

Pretty common with manuals. Mine does it as well. Same deal - goes away above 1,500rpm.

 

[Joseph Donnelly]

It's probably the clutch disk. Not a real problem, but it's better to avoid the situation.

 

[draymorris]

My 03 does this as well. I thought I read somewhere that it was clutch chatter and no big deal. I am not real good with clutches, so maybe someone on here can explain if it is possible for the clutch design to allow "chatter". My question is - does it mean the clutch is worn? - Mine seem to get louder with the miles. By the way, these transmission can pull over 20K of hay on a 40ft 7500k trailer, redlined up a steep hill in 3rd. I did this with a 5 spd for a while and the front bearings went out at 50k miles.



Hope some one can explain what the noise is.

 

[Tomeygun]

just thought i'd mention a fix for a problem a good customer of mine had,



he had a low engine speed knock, and I mean a loud, LOUD knock that happens when you let out the clutch and the let the engine pull at about 1000-1300 rpm, the fix you ask ??





would you believe a loose injector? The injector was loose enough that when fired, would move up and down hard enough to create sound... hmm, I couldn't believe it, but the sound is now gone !!

 

[JRensel]

2004 clutch chatter

In picking up my new truck today I found the same thing, that is... . in first, second or third gears at lower speeds there is a definate noise, hard to describe, not real irriitating, but not what I have heard in other new 6 speed trucks.



Almost like a speedometer cable nose, but its not that cause if you put the clutch pedal down, it stops. It probably makes the noise in higher gears and speeds too, its just you cant hear it.



This is a lot purchase, so I told them no dice until they fix it. They said there was a service bulletin for some 03s but none for 04 (yet) but they will install a new disc tomorrow (only because I am holding the deal hostage). Here's hoping that fixes it.



Anyone have the link to the 03 service bulletin?