Oil pump idler gear

[3twinridges]

Building an 8BA with the boys. First thing I need to do before I put a coat of paint on it is install the oil pump idler gear and gear cover. When I press the pin into the block, how loose should I leave the gear on the pin. Said another way, what size feeler gauge should I use when bottoming the pin out so it will still spin freely?

JB

 

[v8fordman]

The shoulder on the idler gear shaft will not allow it to go in enough to prevent the gear from turning.

 

[3twinridges]

Roger that sir, thank you.

JB

 

[petehoovie]

Building an 8BA with the boys. First thing I need to do before I put a coat of paint on it is install the oil pump idler gear and gear cover. When I press the pin into the block, how loose should I leave the gear on the pin. Said another way, what size feeler gauge should I use when bottoming the pin out so it will still spin freely?

JB

 

[mcgarrett]

Be sure to check the bushing in the gear for excess looseness before you close everything up. It should be able to spin smoothly and easily without looseness or "rocking" on the shaft (pin). If the bushing is worn excessively, the engine will sound like it has a rod knock at idle. I found this out the hard way!

 

[19Fordy]

Double check to make sure you install the gear with the teeth pointing in the right direction of rotation. Hope someone posts photo of the correct install.

 

[19Fordy]

Be sure to check the bushing in the gear for excess looseness before you close everything up. It should be able to spin smoothly and easily without looseness or "rocking" on the shaft (pin). If the bushing is worn excessively, the engine will sound like it has a rod knock at idle. I found this out the hard way!

7/17/25 THANK YOU for posting that information. I bet it's something most folks were not aware of - me included.