Service Department

 SERVICE SPECIALS

HARLEY-DAVIDSON^®

CAM CHAIN ADJUSTER SERVICE

Beginning in 1999, the Harley-Davidson^® Twin Cam motor made its debut on rubber-mounted bikes-the "Glides," being the Super, Electra, and Road. In 2000, a counterbalanced Twin Cam engine found its way into the solid-mount Softail line.

With the addition of a second cam, the camshafts were now driven off the pinion shaft via sprockets and Hyvo chains.  One chain connected the crankshaft to the rear cam via a sprocket, while the front cam was driven off the rear cam.  Cam chains were kept taut with spring-loaded cam chain tensioners made from Dupont Vespel.

With the '06 model year, H-D^® launched the new Dyna Glides, which featured a completely redesigned camshaft system. Roller chains and sprockets that are similar in design to a drive chain and traditional sprocket replaced the Hyvo chains. Instead of spring-loaded tensioners, the new units use hydraulically activated tensioners that operate in a similar fashion to a lifter (tappet). The two case bearings were increased to 1-inch diameter, and the cam plate no longer contained any bearings. Instead, the camshafts rotate in well-lubricated aluminum journals. These plain cam bearings were designed to reduce complexity, run more quietly, and increase durability. Due to this change, new, lighter, camshafts were also employed.

The '06 Dynas were the test bed for things to come. All of the '07 and ’08 Twin Cams now have the same cam components that debuted on those Dynas.  Currently, H-D^® doesn't offer those '06/'07 parts to retrofit earlier models.

1999 Touring models and all 2000 – 2006 V-Twin owners should be aware of cam chain adjuster wear and potential cam bearing failure.  The pitch on the cam gears can vary from bike to bike or more so cam to cam. When the gear pitch varies the cam chain will wear prematurely and can cause the chain to develop burns and cause the chain to stiffen up. This can eat into the soft phenolic cam chain tensioner shoes like a chain saw.  Debris from worn parts can be sucked up into the oil pump and cause damage to the pump and jam the pressure relief valve.  Oil light flickering or blown oil filter seal can result.

Cam chain adjusters from a twin cam engine with 30,000 miles.  Note the excessive wear on the rear adjuster and debris found laying in the bottom of the case.  

As there is no set mileage when tensioners wear out nor is there an established service interval that suggests replacement, we strongly recommend a cam chain adjuster replacement at 25,000 miles.   This will not only result in extended service of your engine, it will also prevent extensive damage and the possibility of leaving you stranded along the road.

 

CAM SERVICE SPECIAL

 PARTS AND LABOR:                                 $800.00 plus tax