Lotus 910 Rear Main Seal Alignment Tool

I designed this tool to replace the Lotus tool T000T0084A, which is no longer available. It's designed to help align the rear main seal and carrier housing. The features key into the end of the crankshaft and pilot bearing (note that the spigot is sized for the ball bearing pilot used with the Renault UN1 gearbox (the Citroen gearbox uses a needle roller bearing which I believe has a smaller ID).

This should be printed with ABS or a similar filament - strength, layer bonding, and oil resistance are important features. Don't use a fiber-filled filament as this runs the risk of embedding fibers in the seal and wearing the sealing surface of the crankshaft.

Use the two small pins to properly align the handle and body when gluing the two tool parts together. This will ensure the vents align and allow easier tool extraction.

Lightly sand the outside of the tool body and the “vertical” interior surfaces. The goal is to smooth any layer lines and bumps from seams. Don't sand so much that dimensions change - this is just to allow the seal to slide easily and to remove bumps which may prevent easy sliding on the crankshaft. I used 1200 grit and sanded for a total of about 30 seconds.

The thin ring is to set the seal insertion depth in the housing (spec is 2mm +/- 0.25mm from the inside surface of the housing). The ring is 2mm thick.

Oil the inside and outside surfaces of the tool body to allow the seal to slide more easily and to ensure lubrication between the seal lip and the end of the crankshaft.