Twin Cam Chain Tip

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Twin Cam Chain Tip

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Twin Cam Chain Tip - 2/1/2006 6:19:25 PM

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Twin-Cam Chain Tip
How to Make Chain Tensioner Shoes Last Longer

By Jeff Deasey
Photography: Jeff Deasey

Most twin-cam engines that we've torn into, show a very significant amount of wear on the chain tensioner shoes by the time they've hit the 25,000-mile mark. Harley recommends replacing them when the wear reaches the half-way mark. So, if your bike has high-performance cams and is nearing the 30,000-mile mark, you just might think about taking a look.

We picked up a trip from our good friend and fellow techhead, Tracy Spencer, of V-Twin City in Santa Ana, California. This little tip involves smoothing the outer circumference of the cam drivechains with a polishing wheel.

Since the chains are made of steel and the tensioners are made of nylon, smoothing the surface of the chain that comes in contact with the tensioner shoes helps a great deal. Tracy reports that he's noticed reduced tensioner wear after polishing the chains, so we've been doing it this way ourselves for the past few months.

You'll need all the same special tools necessary to change twin-cam camshafts to complete the operation

You'll need to get a factory manual and twin-cam tools to get this far. Once you do, follow the procedure listed to remove the cam support plate.

With the support out of the bike, you can now remove the four screws that hold the bearing retaining plate in place. You'll need a T-20 Torx bit to remove the screws.

Now press out both cams and bearings using a hydraulic or arbor press. You'll also have to remove the old bearings from the camshafts and replace them with new ones, since the removal process puts too much stress on the ball bearings to safely use them over again. Remember to catch the cams before they hit the deck as you press them out.

You'll have already removed the outer cam drivechain before the cam support was pulled from the engine, and the inner chain is simply pulled from the cams after they are pressed out of the support plate. Here we start with a little emery compound applied to our buffing wheel. We'll be using emery and then moving to finer buffing compounds until we're satisfied that the chains are smooth enough.

We used emery, before moving onto the less abrasive Tripoli buffing compound, and our final polishing will be done with Jeweler's Rouge applied to the buffing wheel. Although Jeweler's Rouge is most often used on non-ferrous metals (aluminum, brass, copper...), we find it gives us good results when used on our steel cam drivechains.

Since the buffing compounds are abrasive, it's extremely important to clean each chain as thoroughly as possible after buffing them. We soaked both chains in the solvent tank and blew them out with compressed air. Then we repeated the process to make sure there were no traces of abrasives left.

Look at the difference between the unpolished chain at the bottom of the photo and the polished one at the top of the frame. It's easy to see why Tracy's little tip can make the tensioner shoes last longer.

We dropped by the local dealer and picked up a set of new inner and outer cam chain tensioners. Notice the difference between the well-worn one at the top and the new one at the bottom of the photo.