Camshaft Timing Chain and Tensioner Removal

Special Tools 

EN 50837  Timing Chain Tensioner Retraction Tool

For equivalent regional tools, refer to Special Tools .

Fig 1: Upper Timing Chain Guide And Bolts
Courtesy of GENERAL MOTORS COMPANY
1. Remove the upper timing chain guide bolts (2, 3).
2. Remove the upper timing chain guide (1).
Fig 2: Timing Chain Tensioner, Bolts And Gasket
Courtesy of GENERAL MOTORS COMPANY
3. Remove the timing chain tensioner bolts (1) and timing chain tensioner (2).
4. Remove the timing chain tensioner gasket (3) and discard.
5. Compress and lock the tensioner using EN-50837  retention tool.
   1. Insert EN-50837  retention tool into the lever arm and push in a counterclockwise direction.
   2. Compress the tensioner while holding lever arm.
   3. Relax the force on the lever and tensioner slightly, allowing the tensioner to extend 3 ratchet clicks, and then hold in place.
   4. Pull lever clockwise using EN-50837  retention tool until the hole in the lever aligns with the hole in the tensioner assembly. Push the point of EN-50837  retention tool through the lever and into the tensioner assembly.
Fig 3: Timing Chain Tensioner Pivot Arm And Bolt
Courtesy of GENERAL MOTORS COMPANY
6. Remove the timing chain tensioner pivot arm bolt (1).
7. Remove the timing chain tensioner pivot arm (2).
Fig 4: Timing Chain Guide And Bolts
Courtesy of GENERAL MOTORS COMPANY
8. Remove the timing chain guide bolts (1).
9. Remove the timing chain guide (2).
Fig 5: Timing Chain
Courtesy of GENERAL MOTORS COMPANY
10. Remove the timing chain (1).
Fig 6: Timing Chain Oil Nozzle
Courtesy of GENERAL MOTORS COMPANY
11. Remove the timing chain oil nozzle (1).