I have a Mr. Alternator 200 amp alternator on my truck that I am very happy with. The pulley on this particular alternator is significantly smaller than the pulley on the stock alternator. When I installed the new alternator I also had to go buy a new, smaller gatorback belt. Ever since I installed this alternator and new belt I've noticed that the belt will slip sometimes. Especially if I'm off-roading and the belt gets dusty. Now, my question for all of you is do you think I could remove the pulley that came on the new alternator and change it out with the pulley that is on the stock alternator and is there anything I'm going to have to worry about later if I were to change them out. Thanks

-Rob

 

Rob, so long as the Alt. housing are similar (nose/front bearing support) and the shaft diameters are the same you should be able to switch them out. You may need to space the pulley in or out a little to line it up.

For the most part high output Alt. are usually OEM housing with a modified stator. Running a larger diameter pulley will change the output/RPM curve slightly due to the change in pulley diameter. Nothing I would be concerned about unless there's a radical difference.