Repairing A Damaged Cam Thrust Surface is Easy!

Many times Small and Big Block Chevy engine blocks are damaged on the timing gear/camshaft thrust surface. Wear and tear from high milage and or high valve spring loads can cause the back side of the timing gear to "eat away" at the front surface of the block. This area can be restored to better than new by using the Thrust Repair Tool by McLain's Automotive. This tool allows the use of ordinary hand held valve grinding equipment to make a repair that's fast, accurate and permanent.

Shown is a Chevy Small Block with a cam thrust surface that has been damaged by the timing gear, it's actually "eaten away" the metal of the block. This damage can easily be repaired by first resurfacing the damaged area with the cam thrust surface repair tool and then installing a hardened washer behind the timing gear. On a badly damaged block more than one thrust washer can be used without causing any problems.

The repair tool is avaliable in two versions, one for the small block, the other for the big block(they both work exactly the same).

After removing the cam bearings from the engine the tool is inserted into the block. Then a .375 diameter valve guide pilot is inserted into the tool. It makes no difference what brand of equipment you use the tool will still work fine.

Dress a valve grinding stone to 90*, the diameter is not critical as long as it is larger than the OD of the thrust washer it will work without problems. Grind the thrust area of the block. On the Small Block engine a straight edge laid across the front face of the block is used to measure the amount of material that's being removed. Grind and then check the distance using your thrust washer like a feeler guage until you are at the correct depth. Once you are there, you're done! Again, severely worn or badly scored blocks can be fitted with more than one washer if needed. Shown here is the hardened steel washer sold by Cloyes other versions from other vendors may be thicker or thinner, this does not matter. On the Big Block engine the measuring is slightly different because on that engine the thrust is not even with the rest of the front of the block but is instead recessed. Using a short straight edge across the Big Block's larger thust area and measuring the same as with the Small Block works fine.

Shown here on this Big Block is the now repaired thrust surface, ready to clean up and assemble with the thust washer for a better than new repair. The camshaft thrust repair tool is avaliable for $65.00 from Silver Seal 1-800-521-2936 or 734-479-2255 www.silver-seal.com