Re: 20 Hp Chrysler Outboard
The drive shaft is splined on both ends; one end inserts into the crankshaft and the other inserts into the pinion gear on the lower unit. The only thing that keeps it in place is the drive pin for the impeller inside the water pump.
Usually, there is no problem separating the lower unit from the midleg and all you need to do is pull it down after removing the mounting bolts and separating the shift linkage. No need to worry yourself about exerting "downward force" on the drive shaft.
Sometimes, due to a bit of corrosion, the drive shaft will stick in the crankshaft. Then, when you pull off the lower unit, the drive shaft MAY come out of the pinion and the impeller drive pin will be forced through the top water pump seal. This will damage the seal and may also bend the pin. This is NOT a major problem since both the pin and seal are replaceable for relatively few dollars.
However, you will need to fabricate some sort of puller if the shaft is stuck in the crankshaft. Last time it happened to me, I drilled a hole just slightly larger than the shaft in a piece of heavy steel plate. When cocked on the shaft it gripped it and I used a slide hammer to remove the shaft. This marks the shaft though so do it in a spot where the shaft does not ride in a bearing or seal.
No damage will be done by having the drive shaft pull out of the pinion and even the whole lower unit. Just keep the lower unit vertical so that oil does not leak out the shaft hole and mess up your floor.
If the drive shaft does come out of the pinion, no harm is done. Nothing will have shifted or changed position. You simply re-insert the drive shaft into the lower unit and turn until the splines line up with the pinion splines, then push down into its normal position.
For parts for that engine, go to (google) The Chrysler Crew and contact franzmarine. Franz will have almost anything you need.
