Author	[Modern View]
UP Oliver 07-18-2012 07:51:32 68.70.134.91 Report to Moderator	I need to replace the front crankshaft oil seal on my David Brown 990. I have the new seal, but I see where there is a groove on my pulley shaft, which is where the seal goes. I slid the old one on there and am sure that is where my problem is. I saw somewhere last night looking around on the internet where you can buy something that slides over that groove; the guy writing about it called had some slang term for it. Anybody know what it is or where it can be bought? Thanks. [Reply]   [No Email]
RGMartin 07-18-2012 13:51:44 98.21.108.140 Report to Moderator	Re: Crankshaft Oil Seal in reply to UP Oliver, 07-18-2012 07:51:32   How bad is the ring around the pulley? Unless it is really rough just installing a new seal should seal it up, if it doesn't you have other issues, like worn rings and a plugged breather. I wouldn't put that grungy old felt behind the seal, it is going to cause more harm than good. The new seal I have here doesn't have a number, but is 2 7/8" x 2 1/8" x 3/8" thick. This post was edited by RGMartin at 14:06:37 07/18/12.   [Reply]  [No Email]
UP Oliver 07-18-2012 14:32:02 68.70.134.91 Report to Moderator	Re: Crankshaft Oil Seal in reply to RGMartin, 07-18-2012 13:51:44   Those are the dimensions this one has. The ring really isn"t bad in my opinion. I think it has been there for awhile and I probably missed it when I did the rebuild. The new seal I have here seems a lot better than the one I got with the rebuild kit. I will probably look around for a washer and if I have no luck I"ll just put the thing in. It has a little smaller inner diameter so maybe it will be OK. Thanks again.   [Reply]  [No Email]
RGMartin 07-18-2012 10:10:18 98.21.108.140 Report to Moderator	Re: Crankshaft Oil Seal in reply to UP Oliver, 07-18-2012 07:51:32   I would think a decent old fashioned hardware store would probably have a solution. As to the oil making its way through the splines, I put a dab of silicon under the washer when I remember to. The pulley should be pretty tight on the splines, and I don't think I ever had one leak when I forgot to use the silicone, probably a non-issue. Did you compare your new seal to the old one? Do they even run in the same place?   [Reply]  [No Email]
UP Oliver 07-18-2012 12:35:09 68.70.134.91 Report to Moderator	Re: Crankshaft Oil Seal in reply to RGMartin, 07-18-2012 10:10:18   I have to believe they will run in the same place; the new one actually looks a little smaller on the inner diameter, maybe that is a good thing, but it makes me wonder if he gave me the right one. The guy sold me a National 6879H seal. It has the same dimensions as my old one supposedly has. Can I make sure he gave me the right one with some kind of cross reference? I think he just went on dimensions, which should work as far as I know. The other option I have is that I still have my old felt ring around from when I rebuilt the engine. It is a little crispy, but if it is only a spacer I wouldn"t think that would matter much. Do you think I could use that instead of a washer? I don"t want to screw this up and have to spend another $20 - $30 for another seal. Thanks again, and sorry for so many questions.   [Reply]  [No Email]
RGMartin 07-18-2012 09:40:35 98.21.108.140 Report to Moderator	Re: Crankshaft Oil Seal in reply to UP Oliver, 07-18-2012 07:51:32   Make or find a washer that is an 1/8(thick enough to get out of your worn area) or so thick that is just smaller than the outside diameter of the seal, and not wide enough to interfere with the rubber part of the seal. This washer will give the seal something to bottom against, so that is stays square with the bore. I usually have enough junk laying around to make/salvage one out of. Many pump rebuild kits have a plastic washer in them for just this purpose.   [Reply]  [No Email]
UP Oliver 07-18-2012 10:03:54 68.70.134.91 Report to Moderator	Re: Crankshaft Oil Seal in reply to RGMartin, 07-18-2012 09:40:35   I was just out there taking some measurements. The housing for the seal is 7/8 inch deep. The seal is 3/8 inch thick, there is an extension on the pulley that goes in the bore about 5/16 inch, and the felt ring is around 3/16 thick. That all adds up to the depth of the housing, although I' sure the felt ring can be compressed. I can't make one, any idea where I can get one? Also, I understand how the seal keeps oil from leaking outside the pulley shaft, but what keeps it from leaking through the space inside the shaft and outside the end of the crankshaft? Is the washer just inside the nut on the end supposed to do that? Thanks again for your help.   [Reply]  [No Email]
RGMartin 07-18-2012 08:42:24 98.21.108.140 Report to Moderator	Re: Crankshaft Oil Seal in reply to UP Oliver, 07-18-2012 07:51:32   The easier way is to either set the seal deeper or shallower than original. There is lots of depth to that pocket to play with.   [Reply]  [No Email]
UP Oliver 07-18-2012 09:15:13 68.70.134.91 Report to Moderator	Re: Crankshaft Oil Seal in reply to RGMartin, 07-18-2012 08:42:24   I had thought about that, and now that I just got off the phone with the guy at the parts store and he is talking about $50 to $60 for a kit (speedi sleeve is the term I know now); well, I really want to think about it now. How would you suggest I adjust that seal? Thanks for the help.   [Reply]  [No Email]