5000 Strong & Climbing
Join Date: Aug 2011
Location: Davenport, Iowa
Re: Oil Seal or Muffler leak?
A lot of good information in this thread and as always everyone is entitled to their opinions. I would like to add a couple of points here. There are basically two types of fail regarding the oil seals. The rubber seal itself that rides against the crankshaft fails and allows weeping of the oil past the seal and down the crank. The other failure is the seal working it's way completely out. The first type of failure could be caused by a number of things such as old age, (the seal has been on the mower for a long time), when the seal was installed the crankshaft had a burr or rust which may have damaged the seal, and I supposed just like most everything there is a shelf life for oil seals as they are a rubber compound and will, over time, get hard and brittle. How long this will take is anyone's guess but how they are stored may have an adverse affect on the rubber. Lawnboy used the green coated seals for a long time such as the ones Mike is referring to. Whichever seal you choose, proper installation is important to make sure the seal stays in. Clean the crankcase thoroughly and remove all traces of oil before driving in the seal. Only oil the crankshaft lightly to aid sliding the seal on. I have not had any seal that I installed this way, either the metal green coated ones or the rubber ones work their way out of the crankcase. As far as oil in the muffler goes, there will be unburned oil in the exhaust and when you remove the muffler on these old pre F series "Boys" you will more than likely see carbon and unburned oil in the bottom of the muffler if you are using standard dino 2 cycle oil. Some of this may come out the exhaust during operation. The muffler seals are pretty much all compressed in the groove on these old mowers and they are rarely replaced. There should not be oil coming from the seam between the muffler halves. Replacing seals on these old "Boys" can be a good preventative maintenance if you know they have been in there a long time. Otherwise just wait until they show a bit of leaking onto the crankshaft and then replace as needed. Bill
1968 Lawnboy Model 3054******1973 Lawnboy Model 8231******1974 Lawnboy Model 5023
1975 Lawnboy Model 5024******1975 Lawnboy Model 5273******1976 Lawnboy Model 5274
1976 Lawnboy Model 8234EX****1977 Lawnboy Model 5024******1978 Lawnboy Model 5269G
1979 Lawnboy Model 7268******1980 Lawnboy Model 5247******1982 Lawnboy Model 5247
1982 Lawnboy Model 5247*******1972 Lawnboy Model 1015******1972 Lawnboy Model 1015
1987 Lawnboy Model 1400CL****1995 Lawnboy Model 61638
Where there's a will, there's Mr. Bill!***They don't call me MacGyver for nothing!***I have LBAD and DCAD!