Last minute partial engine drop and Speedi-sleeve repair

[buster73]

Should have been suspicious that things were going so smooth. After my recent engine drop (Engine Drop - Stealth Mode) everything seemed to be o.k. but after some shake down runs the new pulley seal was starting to leak more and more. With the big R-Gruppe meeting coming this weekend, it was a tough decision to either let it leak or to repair now. After I was able to get all necessary spare parts, I decided to do a partial engine drop to have a closer look. With the pulley removed I found fine metal shavings and abrasion marks around the pulley seal. To my surprise it turned out that the pulley was touching the seal. This was the result of two seemingly minor modifications. When I removed the old seal, the crankshaft showed a minor notch were it was in contact with the sealing lip (acceptable after 250K mi). In order to avoid any sealing problems, I decided to not fully push the seal all the way into the crankcase, so the sealing lip would run on a virgin area of the crankshaft. The difference was less than 1 mm (1/32“) and should have not caused any problems. Unfortunately at the same time I had the pulley powder coated using a silver ceramic coating. Looks great but the build-up was quite thick and I decided to scrape away the coating where the pulley contacts the crankshaft to avoid that the pulley might work itself loose over time. Unfortunately I did not shave of the coating from the surrounding rim of the pulley. After assembly the coating of this pulley rim must have just touched the seal. The hard ceramic coating was then slowly grinding away and even abraded the metal frame of the seal. The shavings accumulated around the sealing lip, destroying it in the process.

Fortunately the solution was quite easy. After removing the old seal I installed a „Speedi-Sleeve“ on the crankshaft to cover the notched area. Then I installed a new seal (fully seated this time) and reinstalled the pulley.

Of course there were some additional projects while having the engine partially dropped and the oil drained. I removed the left heat exchanger and installed a new oil line (engine to tank, two-piece 74+) to replace my old 73 one piece line. I also installed the oil line restrictor kit from our host which should help to boost the idle oil pressure when hot. The whole procedure took less than 2 hours and seems this time everything works out. Another lesson learned and Sonoma here we come !!!.


Engine just dropped enough to access to the pulley.


Speedi Sleeve (sorry not available from our host).


Speedi-Sleeve installed with some sealant.


Pulley seal installed (front edge of Speedi-sleeve just visible)