Timken Insert and Installation

At T-Man Performance, we pay special attention to the installation of our Timken inserts. Rather than using the same methods as other companies, we only do a case insert with both right and left case halves.  What we have found is that the cases are not concentric from the factory. It is not uncommon to see the left case or sprocket shaft side off .003”-.005” from the right case pinion bearing bore. When this is the case, and you install a pre-machined insert in the existing case hole, your cases are still not aligned properly. Others enlarge the existing bearing area for a larger aluminum race.  At T-Man we start with a custom made steel insert.

The first step in the process is to install our ground plate to the right case using all 10 ¼-20 screws installed at the factory. (Note-all case machining is done from the cam cover surface from the factory).

The plate is then secured to the mill table.

The pinion bearing bore is indicated for roundness and straightness to the gasket surface (Note-once the right case is secured to the mill bed and indicated, the mill bed is never moved).

At this time we install the left case and secure it to the right case already on the mill. The left bearing bore is checked for alignment with the right bearing bore. Typically, we see these off .003”-.005” on a set of later style cases.

At this time, the boring of the left case is started.

When the left case is done, you have a set of cases that is completely aligned from the right bearing bore to the left bearing bore.

We remove the left case and put it in our oven for preheating while the steel insert is in the freezer. When the case reaches the proper temperature, we install it on a custom made fixture that insures the insert is installed straight and doesn’t damage the bore on the left case.

Now, the insert is secured to the case with four tapered screws and the oil feed hole and oil drain hole are drilled.

At this time, the final step in the process is ready to be performed.  We reinstall the left case onto the right case for the final time. (Remember the right case has never moved from the time we indicated the bearing bore).

Now the steel insert is ready to be sized for the timken bearing races.

This process provides the highest quality outcome. We won’t be the least expensive of shops doing timken insert and installations, but we will have the highest quality.