Technical Service Bulletins

Coated Cam Bearings

Order Reprints
Coated Cam Bearings

GM now recommends any cam bearing replacement in a Gen IV V8 engine (LS series) to use coated cam bearings in all five positions.

The new cam bearings feature a black polymer coating. Note that if the black coating wears off, this does not indicate a bad bearing. There is still a lead lining material underneath.

Of course, if the lining is damaged or worn beyond specification, replacement is required. The maximum cam journal to bearing oil clearance is 0.005-inch on engines equipped with AFM or CMP. Maximum oil clearance for engines not equipped with AFM or CMP is 0.006-inch.

Refer to the GM parts catalog for cam bearing part numbers, which will be different for positions (1 and 5 use the same part number, positions 2 and 4 use the same, and position 3 features a separate part number). Part numbers will also differ based on the use of iron or aluminum blocks.

Related Articles

Subaru transfer driven gear bearings

Excessive cam bearing clearance may set DTCs

Chevy Cam Solenoid

You must login or register in order to post a comment.