transmission winding

Hey guys i just replaced the tranny on my 88 sierra the tranny in it now has 135,000km on it .. but whenever it running or if i'm driving in gear it makes a winding noise but when i put the clutch in it stops but it wasnt making that noise with my old tranny have any ideas what that is and if i should be worried? thanks guys

short and simple, throw out bearing, I hope they installed a new one, i would go back and ask the shop

whats is a throw out bearing and what does it do?

throwout bearing- is a sealed bearing that goes around the input shaft of the tranny, it has a notch machined around the edge so the "fork" can move the bearing along the shaft. this fork is the lever inside the bell housing of the that moves in and out when you depress the clutch pedal; engaging and disengaging the power from the tranny. when this bearing starts going bad it will make noise when it spins along with the trans shaft. when you depress the clutch pedal it engages the bearing to the clutch assembly and puts the bearing under a load, that's why the sound goes away when you push the clutch in.
good luck

thank you but if this bearing is bad or hasnt been replaced whats the worst that could happen if i keep driving it like that . ?

i suppose the worst that could have is the bearing will eventually fail and the trans shaft would be galled. and you will have a lot worse sound than you have now. if the bearing fails and come apart the pieces will get into that brand new clutch disk and ruin it. it makes it kind of hard to shift without that bearing too....

ok but does that bearing come with the tranny? like i wonder if that bearing is from the truck or the machanics installed it with the tranny...

you can get the bearing by it self, but the tranny will have to come out of the truck to get it in. i think your best but would be to take it back to the shop and have them fix it