Vehicle: '03 3500 w/ 6spd manual trans 110k miles

My tranny is out now for a clutch change, and I have been hearing a bit of bearing rattle (which I suspect is the input shaft bearing?) in 1st and 2nd at very low rpm (goes away as engine rpm rises above maybe 1200 or so).

1) Am I correct it is the input shaft bearing?
2) Does the trans have to be disassembled to replace it (or can it be accessed from the front seal area)

My impression (since I hear this from other vehicles) that it's no big deal, but since I have the trans out anyway, if it can be done relatively cheaply and easily, I'd just as soon not listen to the occasional noise (the trans is dead quiet in all cruising conditions), especially if it means the bearing is going to crater soon.

Thanks,
Bob
Waxahachie, TX

 

Check the throw out bearing to. If the input shaft bearing is bad, the input shaft would have abnormal amounts of play. Change the clutch, do the throw out bearing, pilot bushing, and grind the fly wheel.

 

Though the truck has only 110,000 miles, and the clutch shows no measurable wear whatsoever (the truck was never used to tow anything by the prior owner), I AM changing the clutch, pressure plate, throw-out bearing, and pilot bearing.

I doubt the noise is from there (seeing it's only in the lower gears) but for $350 more, it's worth it, especially since I had to do a complete rebuild at $8k plus total due to a small gouge in #1 cylinder causing blow-by.
Bob

 

Ya go ahead and spend the money and do it right IMO

 

The clutches themselves in these make a little racket, like when idling around a parking lot in 2nd gear. It's the spring-loaded hub in the center of the clutch disc. When the RPMs climb above idle, it puts a steady load on the hub and it quiets down. Very well may be what you are hearing.

 

I have the same noise comming from my 6 speed manual cummins. its an 03 as well. Low gears it makes the noise but when i start giving it gas and start croozing its fine. Some people told me its nothing to worry about but is annoying every time i take off. Any help as to where this is comming from would be sweet! Thanks

 

The rest of the story-

I authorized the shop to replace the input shaft bearing, and the trans was sent off to the trans shop, who got the story wrong and did a complete rebuild w/ all new bearings, synchros, etc. (which the trans did NOT need).

The noise is gone, but 20k later I can hear the very slightest return of it.

The noise is only in gears 1 and 2 at the lowest RPM when starting off (not at idle w/ the clutch released). It's more of a rattle than your usual noisy input bearing sound you hear in neutral w/ the clutch pedal released.

Personally, I suspect it's not harmful.