Friday, February 17, 2017

Timing Cover Oil Seal Retainer

This is an area that receives  a lot of attention on the Interceptor discussion board. It is a known weakness in the Series II Interceptors that can wreak havoc on an engine. So what's at issue here? The timing cover seal does not have a mechanical lock and can shift into the oil pump gear destroying itself. Although I have not come across many occurrences of this issue it sounds like a genuine concern needing attention.
As delivered from the factory. The lower seal has no retainer.

There is not much real estate to work with when addressing this issue but many clever solutions have been devised. The method I liked best is a retaining clip but it did not look like there was enough room to work with and my machining skills are a bit rusty to attempt it on my one and only cover. Another popular method is to drill holes and put in retaining wires which looked difficult to do with the limited amount of space. An idea I liked was drilling small screws (44-40) into the boss and putting washers on the them to hold in the seal. Here again it looked like it would work but the amount of material is small so I went a different route. I decided to anchor a retainer on the seal boss supporting rib. This is a method which was recently covered on the Yahoo Groups Interceptor discussion board. My approach is a variation of that method. .

My print and business card prototype. Instead of pinning the gear end of the retainer I will use leverage against the rib it is anchored on for hold down pressure. 

Holes drilled and cutout complete. 

Bent and fit into place. Time to check clearance, modify as needed, and drill the hole. 

The progression; print,prototype and part. Custom fit via my "apprenticeship project" vise, machinist ball peen hammer, and an aluminum block pulled out of the scrap bin at work. 

The hole location was transferred to the rib from the bracket and drilled with an air grinder. It was straightened with a carbide burr and opened up to fit the screw. 

The bracket was fit with a 10-32 cap screw, washers and locking nut. After mounting, final adjustments were made to make sure the retainer fit snug against the seal boss and cleared the shaft. 

And the top......

And the opposite side......The cap screw made it easier to tighten than a hex head bolt. 

Overall the project went pretty smooth. Thanks go out to the people who figured this out and shared what they learned. I'm one step closer to having another Interceptor on the road!

The Interceptor cylinders bored and ready to go. E & V Engineering in Howard City Michigan did the work. They are regional British bike experts and offer many services and parts for British motorcycles. Check out their site and custom part offerings including many for BSA singles.

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