Product Description:
1999-2013 GM LS Truck/SUV HD Belt 6-Rib Tensioner & Bracket Kit 4.8L 5.3L 6.0L
**Kit includes AFP HD tensioner bracket and AFP 6-Rib HD tensioner with billet aluminum pulley**
This is a bracket to be used on factory style truck water pumps to allow easy mounting of an off the shelf HD tensioner. This is especially useful for LSA swapped trucks that use the LSA supercharger on the factory 6 rib system. This is also recommended for high-rpm vehicles to keep the belt on if you experience that issue. If you want to use an 8 rib tensioner you will need to purchase it yourself. Part number is Gates 38518 and should be available online or through your local parts store. This purchase includes the bracket, SS hardware and the center grade 12.9 bolt, locking nylon nut, and 2 washers. This is made from 3/8″ steel, it is very strong and utilizes all 3 mounting points to the water pump. The 3 factory mounting bolts are reused. A spring-loaded automatic tensioner is preferred over a manual style tensioner whenever possible since it will accommodate natural belt stretch and is also easier on bearings when loaded.
The 6-rib tensioner bracket kit is aligned exactly to stock belt path and functions similar to the stock one, just with more tension.
Mounting and Installation: There are several mounting positions (5 holes) which can be used for the tensioner tab to rotate the tensioner to whatever position works best for you. Depending on belt length and accessories the tensioner will generally point straight up when completely unloaded when installed, but can be rotated as needed. Generally the middle of the 5 holes is the best place to start, but rotate as needed to get the most travel as possible. Ideally you want to have to tighten the tensioner to its full stop and just barely be able to get the belt on all of the pullies. In this way the tensioner has the most room to work and accommodate belt stretch. If the tensioner ever takes up all of its travel the belt will be loose and probably walk or be thrown off. If the tensioner is rotated too far counter clockwise (or too long of a belt is used) the belt may rub the tensioner body from the crank pulley. If the tensioner is rotated too far clockwise (or too short of a belt) the belt may rub the water pump pulley.
Belt: A stock or close to stock belt length should work depending on your pulley combination. The larger case 145a alternator, OD crank pulley, OD alternator pulley, or any other larger pulley will require a longer than stock belt. Any underdrive pullies will shorten the belt needed. If any accessories are eliminated or non-stock belt routing is used that will shorten the required belt. A stock Silverado belt is roughly 93″. Below is a list of Gates belts that will be compatible with the 6-rib tensioner based on complete setup.
