Harley-Davidson Twin Cam Timken bearing conversion Part 3
The new Timken outer races are now installed in the crankcase insert. This requires a service tool and hydraulic press.
The existing INA roller bearing inner race and thrust washer have to be removed from the crankshaft. The race is a tight fit and butts up against a shoulder machined into the flywheel. This requires a heavy duty industrial bearing seperater and hydraulic puller. Fortuneately, although Harley changed the bearing, the actual shaft is the same diameter that it was on the earlier Timken bearing cranks. So other than removing this now reduntant bearing race and thrust washer, no other modification is necessary. This is true of the earlier roller bearing 88" cranks as well as the later, multisplined, 96" cranks.
The inner Timken bearing is installed onto the crank with an S&S service tool. Having already established the spacer required for correct end float, the crankcase is then installed over the crankshaft, and this tool is then used to install the outer Timken bearing and sprocket shaft oil seal. This is covered in more detail in our Harley-Davidson crankshaft installation technicle article.
Because of the change of bearing configuration, the actual location of the crankshaft can shift slightly axially. This isn't an issue, just a potential stack up of machining tolerances. For this reason, and good engine building practise demands it anyway, with the Twin Cam "B" engine, we have to check the alignment of the balancer drive sprockets. Once again a service tool is required. Any adjustment needed is carried out by changing the spacers beneath the balance shaft sprockets. These are available in a range of sizes.
Because the Timken bearing is substantialy wider than the later roller bearing, the sprocket shaft spacer needs to be a different length. The one on the left is the roller bearing version, whilst the shorter spacer on the right is used with the Timkens. This spacer runs in the oil seal and is sandwiched between the bearing inner race and the alternator rotor, and determines primary drive alignment. This gives a good idea of how the bearing widths differ.
Finally, the finished assembly of this 95" 2005 Softail bottom end. Pinion shaft runout is just .001", and will most likely stay that way with the extra support of the Timken bearing conversion.
Powerglides - In The Press