Harley-Davidson Twin Cam Timken bearing conversion Part 2
This Jims Machine installation kit is exceptionally well thought out and manufactured. It is designed to be used with their tool steel Timken conversion insert, and ensures accurate alignment when using the hydraulic press. It also doubles up as a drill jig for drilling the bearing oil feed and oil drain holes, as well as the holes used to help retain the press fit insert.
After coating part of the crankcase bearing housing with a special grade of Loctite, part of the tool is attached to the casing. It locates on the alternator stator spigot and is bolted on using the existing tapped holes in the casing. Part of the insert is also coated in the same grade of Loctite, whilst part of it is coated in press fit assembly lube.
Using other parts of the tooling, the insert is accurately located off of a datum point and pressed into the casing with our industrial hydraulic press.
This drill jig plate is then bolted to the other part of the tooling to prevent any movement. The two drill bits shown, with depth stops, are then used to machine the bearing oil feed and return holes.
On the milling machine we then drill six holes for the retaining screws.
The six holes are then tapped by hand using a simple guide plate to ensure squareness. This is a thread rolling tap which gives a stronger thread than a conventional cutting tap.
After cleaning away all the swarf and cutting oil, the six retaining screws are Loctited and torqued.
The conversion insert is now installed, tooling removed, and is ready to accept the Timken bearings. The outer snap ring, used to locate the Timken outer races in the earlier engines is not used, as it is machined in as part of this intelligently designed insert. Notice also the oil fed hole at 12 O'clock, and the drain hole at 6 O'clock. The small hole on the face of the insert, just below the oil feed, is used as a datum location to correctly orientate the insert with the installation tool. This ensures that all the machined holes line up correctly.
Powerglides - In The Press