If your dryer is noisy, check these:
Rollers
Idler pulley
Glides
Rear drum bearing
Blower wheel
Rollers
Many dryers use rollers or wheels to support the clothes drum. When these rollers are worn, they can be noisy. You should replace the whole set of rollers at the same time.
Idler pulley
Dryers have a tension or idler pulley that keeps tension on the main drive belt. When it's worn, it can be noisy. When that happens, don't lubricate it. Just replace it.
Glides
Many dryers use nylon or plastic glides at the front of the clothes drum for support. When these are worn, they can be noisy. When that happens, replace them.
Rear drum bearing
Some dryers support the clothes drum in the rear with a center spindle instead of rollers. The spindle may be a ball-and-socket type support or a shaft through a sleeve. When the components are worn, they may squeak, squeal, or rub. You can't repair them. Just replace them when they're worn.
Blower wheel
Your dryer's blower wheel pulls air over the heat source, through the clothes drum, and past the thermostats, then pushes it out the exhaust duct. The blower wheel, which is usually plastic, may wear out over time. But if it's noisy, it may simply be clogged with lint. Clean the blower and test to see if the dryer is still noisy. If it is, you probably need to replace it.
You can find your answer at:
http://www.repairclinic.com/0088_8_1.asp#Level1_7