grinding noise when clutch engaged?

[monster man]

I've got this wierd grinding noise whenever I'm coming to a stop or crusing really slow or in reverse when the clutch is engaged (when the engine is compression braking). Less of a grind than a metal on metal rubbing noise. I thought it was a u-joint grinding my muffler but there's no marks on it. It only "grinds" if the clutch is engaged, when I push it in the noise stops, but when it's out it grinds, even with the truck in neutral.
Is one of the shafts or gears in my tranny bad? Or is it in the clutch?
Wish I knew more about diagnosing manual transmissions

On a positive note I got my lift installed this weekend (the noise was there before the lift so I doubt they're related)

Thanks!

 

[mudhog]

sounds like the throughout (sp?) bearing to me

 

[BURB-STYLE]

2nd the throw-out bearing option

 

[MTMike]

The throw-out bearing should only be making noise when the clutch is disengaged (clutch pedal pushed in). It sounds like the only time he hears it is when the clutch pedal is out.

Does it do it in all gears or just 1 gear in particular? Does it increase in frequency or pitch as you increase vehicle speed or engine speed?

Mike

 

[monster man]

that's correct, it's only making noise when the clutch pedal is out (clutch engaged would be the right terminology correct, you push in the clutch to disenage?)

I notice the noise in reverse, low, first, and sometimes second, when I'm coming to a stop and the engine is braking the truck. It's esepcially prevelant when the truck is creeping along slowly, and when I let off the gas.

 

[BURB-STYLE]

if its bad it can make noise all the time, i know cause the brand new one i put in my dakota was defective and it made noise all the time.

 

[monster man]

now that you mention the clutch throwout bearing as a possible culprit, I have noticed an awful lot of squeaking coming from the lower dash area. I keep trying to locate in the cab, but I guess it could be coming through the floor panels?

 

[K10bolts]

Generally speaking, the throwout and pilot bearing will make noise when the pedal is pushed in, and the input shaft bearing will make noise all time unless the clutch is disengaged. I would check the pedal freeplay and make sure it is within spec., then go from there.

 

[randy88k5]

I think its an input shaft bearing. On my old Sonoma it was going, but I didnt care. I drove it into the ground then sold it to my friend who grenaded the motor 3 months later.

Same thing was going on with a friends 22R Toyota pickup. It would disappear when you lightly pressed the pedal.

I think the throwout bearing will make noise when pedal is pushed
I think the input shaft bearing will make noise when pedal is free.

Thats what I remember though...

 

[monster man]

thanks guys. Any additives out there that would give it a little longer life? Not sure if the tranny is leaking fluid or what, but might as well fill it to max. Any cheap tricks to get me by for now on either bearing?

 

[MTMike]

I concur on the input shaft bearing as well.

 

[monster man]

It's wierd, I really only notice it when it's hot, it won't do it when the engine is cold. I'd have guessed the bearing would make noise when it was cold and didn't have lube right away. It's off and on, like at lunch I did a little wheeling in the lot next door and it didn't pop up until I was driving over the curb to leave the lot. Go figure