My elderly ****en Retriever woke me up to get an early morning walk, couldn’t go back to sleep. So, probably did too much thinking, again, but…
There have been some recent threads regarding crankshaft Speedi Sleeves, mid shaft bushings, and lower unit removal and installation, and others where a little extra effort can prevent damage to seals.
Common sense would dictate seal damage prevention. I thought I would pass along some precautions I take while working around seals.
First off, immediately when I remove my lower unit, I wrap tape around the drive shaft splines to protect same. The edges of these splines are sharp. Say you’re replacing the upper lower unit driveshaft seals. Sharp edges of the splines can slice a cut in the seals while placing them over the driveshaft. Granted these seals are somewhat larger diameter than the splines, but if you are careless, you can damage them. So why not take five seconds and put tape around the splines.
What about when reinstalling your lower unit? Of course, you can’t leave the tape on, and I know you all put a bit grease on the splines. I put a fine film of grease over the entire shaft, including seal and mid-shaft bushing mating surfaces. But have you ever had to struggle to line up the driveshaft and shift shaft into their mates? What if while you’re struggling you have the shaft at such an angle to the seals that the splines cut into your driveshaft seals in the oil pump? You must take your time ease the shafts into their mates.
In four stroke oil pumps, there are two seals for the driveshaft. Besides protecting the crankshaft before the crankcase seal, are these seals extra protection to keep contaminates from damaging the first oil pump seal? Could the contaminates promote the seal wear and its mating crankshaft, thus requiring a Speedi-Sleeve repair?
Remember that mid-section bushing, some have said that you can just remove it and don’t bother to replace it. The published purpose of this bushing is to prevent excessive shaft wobble. However, a result of not having the bushing in place, IMO, could be while installing a lower unit the allowance for increased angle could cause seal damage.
There have been some recent threads regarding crankshaft Speedi Sleeves, mid shaft bushings, and lower unit removal and installation, and others where a little extra effort can prevent damage to seals.
Common sense would dictate seal damage prevention. I thought I would pass along some precautions I take while working around seals.
First off, immediately when I remove my lower unit, I wrap tape around the drive shaft splines to protect same. The edges of these splines are sharp. Say you’re replacing the upper lower unit driveshaft seals. Sharp edges of the splines can slice a cut in the seals while placing them over the driveshaft. Granted these seals are somewhat larger diameter than the splines, but if you are careless, you can damage them. So why not take five seconds and put tape around the splines.
What about when reinstalling your lower unit? Of course, you can’t leave the tape on, and I know you all put a bit grease on the splines. I put a fine film of grease over the entire shaft, including seal and mid-shaft bushing mating surfaces. But have you ever had to struggle to line up the driveshaft and shift shaft into their mates? What if while you’re struggling you have the shaft at such an angle to the seals that the splines cut into your driveshaft seals in the oil pump? You must take your time ease the shafts into their mates.
In four stroke oil pumps, there are two seals for the driveshaft. Besides protecting the crankshaft before the crankcase seal, are these seals extra protection to keep contaminates from damaging the first oil pump seal? Could the contaminates promote the seal wear and its mating crankshaft, thus requiring a Speedi-Sleeve repair?
Remember that mid-section bushing, some have said that you can just remove it and don’t bother to replace it. The published purpose of this bushing is to prevent excessive shaft wobble. However, a result of not having the bushing in place, IMO, could be while installing a lower unit the allowance for increased angle could cause seal damage.
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