Lower unit removal issue, '75 Johnson 85 hsp

[Ned120]

Have followed the manual carefully. All attachment bolts are removed and the shift rod is disconnected. The prop end of the unit came down about 1/16th of an inch but the end close to the hull shows no sign of movement. Soaked the mating surfaces in WD 40 to the extent I can. Tried a rubber mallet. Assume there is a lot of corrosion holding it. Was thinking of fashioning a separator of a sort to pull the units apart but am afraid to use the thin aluminum plate projecting horizontally as a brace. Anyone done this job on an old stuck motor?

 

[HighTrim]

Re: Lower unit removal issue, '75 Johnson 85 hsp

Welcome to iboats.

IF all bolts are removed, and the shift rod IS fully disconnected, there is likely corrosion on the splines of the drive shaft. Be sure to add some marine grease to them on re installation, along with a new o ring at the top of the shaft.

She will come apart, just needs a little help. I would put a couple of the larger bolts on loose to grab it when it does finally let go, as well as take off the prop. Prevent it from getting damaged, and then you can grease the splines of the prop shaft as well while you have the grease gun out. You will likely find some old fishing line wrapped around the prop shaft as well, be sure to get this off.

 

[James R]

Re: Lower unit removal issue, '75 Johnson 85 hsp

Did you look for a bolt under the trim tab?
If this is not it and you are quite sure that the shift rod is not hanging up then fashion some slow slope hardwood wedges and try that. The thin parts such as the cavitation plate will not take any pressure.

 

[Ned120]

Re: Lower unit removal issue, '75 Johnson 85 hsp

Have been fooling with it since my original post and lower unit is loose by 1/8th inch all around and just feels like it is hanging from the driveshaft which I assume runs roughly up the middle of the long section containing the exhaust housing. I have the motor in neutral. Is that correct? Can I safely assume that there is nothing to release on the driveshaft itself? It feels as if it is hanging on a circlip somewhere up the shaft though no such issue is mentioned in the manual. The shift rod is safely disconnected from the dual levers behind the carbuerators. Thanks for the quick responses, did not expect such.
All six main bolts are out though the small screw beneath the trim tab was absent. Is that an issue and does anyone know it's dimensions and thread size?

 

[wilde1j]

Re: Lower unit removal issue, '75 Johnson 85 hsp

See Chris' post above.