Product review (4 stars): May as well replace the belt also while you are in this deep.
Samsung Dryer was 10 years old.
The original idler pulley shaft was worn and the dryer produced a low rumbling like a sports shoe was in the dryer. Replacing this assembly removed that rumble. The only negative about the assembly was that the lubricating grease was a glob on the back side of the nylon roller. I took the snap triangle off, pasted the glue onto the shaft under the location the roller would seat and re assembled. Likely this would have been 5 stars if lubrication would have been correctly located on the shaft.
Side Note - This is the first time inside this dryer and the fan had a lot of lint in the blades.  After cleaning the fan the air movement should increase by about 50% with the new roller, no more rumble.
Replacing the drive belt and lubrication of the 4 support rollers with Dupont krytox  hopefully will give me many more years of service. I know there is a big debate about lubrication or no lubrication.....