---------------------------------------------------------- LycomingEngines-List Digest Archive --- Total Messages Posted Sat 08/19/06: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:43 AM - Re: Crank seal (Hopperdhh@aol.com) 2. 08:50 AM - Re: Crank seal (Hopperdhh@aol.com) ________________________________ Message 1 _____________________________________ Time: 08:43:20 AM PST US From: Hopperdhh@aol.com Subject: Re: LycomingEngines-List: Crank seal Gary, I agree with Barry on getting things cleaned really well. I just did this for the first 2 times (2 separate engines) in the past 2 weeks! In addition to cleaning the surface where the seal goes really well (use MEK and a cotton swab) here are a couple more tips. Your case should have a small groove machined about 1/16 inch behind the front surface for an uncut seal to fit to. If you don't have the groove then the case is probably drilled and tapped for 2 retaining plates to bolt onto. This is the old design. When Divco overhauls the case, I think they machine the groove for the solid seal. Be sure this groove is cleaned out also. Also smooth out any burrs on the front edge of the case that could cut the ridge while you are putting the seal in. As far as I know, the solid seal is the only one with the ridge to fit the groove. The split seals are for the old design. To install the solid seal, first remove the spring, unhook it, put it on the crank and hook it back up. Then boil the seal in water for about 5 minutes. Have the crank and bushings free of burrs and put a layer of electrical tape over the outside edge. Start the seal by putting a large Phillips screwdriver or punch through one of the bushings to keep it in place front and back. Also have additional protection in the form of a plastic bag over the flange. I use a bag that parts are shipped in which mikes about 5 mils. Use another large (about 5/16 or 3/8 inch) round screwdriver or punch to get a good grip on the seal and stretch it like a big rubber band over the flange. It takes quite a bit of force to do this. After it is on the flange and before it returns to normal size inspect it for nicks or damage. In 15 minutes to 1/2 hour it will come back to normal size and you can put the spring back in it. Clean the seal and cavity again with MEK but don't let MEK stay on the seal -- just wipe it with a cloth wetted with MEK. Put some Pliobond on both the case and the seal, and slide the seal in. You may need a block of wood and a hammer to get it clear in. (In my case I did it as I was assembling the case halves.) It sticks out just a little as you can see from where the groove is with respect to where the ridge on the seal is. After it is installed, I would oil the seal where it slides on the crankshaft with Marvel Mystery Oil (just my preference) using a small wooden stick to lift the seal and be sure it gets inside. In a message dated 8/15/2006 11:30:15 A.M. Eastern Daylight Time, FLYaDIVE@aol.com writes: Gary: It is a very easy repair. It is a little time consuming because proper installation requires a lot of cleaning. AND I'd bet Dollar$ to Doughnut$ that is where the rebuilder failed. Order a new seal and you should be able to figure it out just by looking at it. Just remember CLEAN the case extra well. Barry "Chop'd Liver" "Show them the first time, correct them the second time, kick them the third time." Yamashiada ________________________________ Message 2 _____________________________________ Time: 08:50:12 AM PST US From: Hopperdhh@aol.com Subject: Re: LycomingEngines-List: Crank seal The following reply was sent by mistake. It was written about a week ago and is terribly out of date now! do not archive Dan In a message dated 8/19/2006 11:44:52 A.M. Eastern Daylight Time, Hopperdhh@aol.com writes: Gary, I agree with Barry on getting things cleaned really well. I just did this for the first 2 times (2 separate engines) in the past 2 weeks! In addition to cleaning the surface where the seal goes really well (use MEK and a cotton swab) here are a couple more tips. Your case should have a small groove machined about 1/16 inch behind the front surface for an uncut seal to fit to. If you don't have the groove then the case is probably drilled and tapped for 2 retaining plates to bolt onto. This is the old design. When Divco overhauls the case, I think they machine the groove for the solid seal. Be sure this groove is cleaned out also. Also smooth out any burrs on the front edge of the case that could cut the ridge while you are putting the seal in. As far as I know, the solid seal is the only one with the ridge to fit the groove. The split seals are for the old design. To install the solid seal, first remove the spring, unhook it, put it on the crank and hook it back up. Then boil the seal in water for about 5 minutes. Have the crank and bushings free of burrs and put a layer of electrical tape over the outside edge. Start the seal by putting a large Phillips screwdriver or punch through one of the bushings to keep it in place front and back. Also have additional protection in the form of a plastic bag over the flange. I use a bag that parts are shipped in which mikes about 5 mils. Use another large (about 5/16 or 3/8 inch) round screwdriver or punch to get a good grip on the seal and stretch it like a big rubber band over the flange. It takes quite a bit of force to do this. After it is on the flange and before it returns to normal size inspect it for nicks or damage. In 15 minutes to 1/2 hour it will come back to normal size and you can put the spring back in it. Clean the seal and cavity again with MEK but don't let MEK stay on the seal -- just wipe it with a cloth wetted with MEK. Put some Pliobond on both the case and the seal, and slide the seal in. You may need a block of wood and a hammer to get it clear in. (In my case I did it as I was assembling the case halves.) It sticks out just a little as you can see from where the groove is with respect to where the ridge on the seal is. After it is installed, I would oil the seal where it slides on the crankshaft with Marvel Mystery Oil (just my preference) using a small wooden stick to lift the seal and be sure it gets inside. In a message dated 8/15/2006 11:30:15 A.M. Eastern Daylight Time, FLYaDIVE@aol.com writes: Gary: It is a very easy repair. It is a little time consuming because proper installation requires a lot of cleaning. AND I'd bet Dollar$ to Doughnut$ that is where the rebuilder failed. Order a new seal and you should be able to figure it out just by looking at it. Just remember CLEAN the case extra well. Barry "Chop'd Liver" "Show them the first time, correct them the second time, kick them the third time." Yamashiada (http://www.matronics.com/Navigator?LycomingEngines-List) (http://www.matronics.com/contribution)