View Full Version : How rear scroll seals fail

05-27-2013, 04:29 PM
Since the topic of rear seal leaks come up so frequently, I thought it'd post some pix showing why a line bore, including the half moon piece and matching section of the main, is required when rebuilding an engine, and why correct venting is not always a fix. Factory tolerance for the air gap is .0015 to .004. Since this part is often not removed or inspected during a rebuild, the problem will still exist.

It was pretty easy to come up with these samples, as pretty much every one I looked at had some sort of similar damage.

The front transmission cover has a similar design and should be inspected for wear in the opening of the cover, as well as the input shaft