Shift Shaft Oil Seal removal 1974 7.5hp

Is there a way to remove the shift shaft oil seal without disassembling the shift shaft? Sorry I can’t post pictures or haven’t figured it out yet and a picture would be handy. What I have is a 7/8” by 3/16” oil seal sitting in it’s own “cup” rubber pointing up around the shift shaft. YouTube had a guy collapsing the seal collar and working the seal out. That would probably work in my case but the seal is so small and I would be running the risk of doing damage to the shaft. Wondering if there is a safer method? Thanks in advance.

I’d be interested in hearing how to post pictures.

Remove the lock screw for the bushing.-----Hold shift rod DOWN and leave it in place.-----Remove bushing.------Install new seal.-----Put bushing back in.

Thanks for the reply. I can’t, the shift shaft protrudes 5” above the top of the gear case.

??---Why is that a problem.------The bushing comes out !

Just a 10 minute job on a fresh water motor.

Got it out, Thanks. The bushing didn’t want to let go. Thats what was confusing me. Your instructions were clear I was apprehensive in using enough force to break it free.

On the prop shaft where the prop shaft seal rides there is a small groove in the shaft. Is this normal? The service manual shows a groove in one of the pictures so I’m assuming that is where the seal rides.

Another question. The service manual is telling me to use a plastic guide tube over propeller shaft to protect oil seals. “Push bearing carrier into gear housing until it seats against ball bearing thrust ring”. I took some pictures before I took the bearing carrier out and I can’t push the carrier as deep as my pictures nor as deep as the manual wants. I should have 4 threads showing on the inboard section of the second set of threads(the slightly small diameter set of threads) My question is can I use a 1 1/2”” of PVC pipe and gently tap the carrier till the thrust ring bottoms out on the gear housing? Thanks in advance

Try assembly in forward gear ?

Bearing carrier is back in, had to gently tap it in place until I felt the carrier bottom out. Hand tightened the gear housing cover and checked for proper F-N-R operation. Turn shift shaft clockwise(forward gear) then turn drive shaft clockwise prop shaft turns clockwise. Then I turned shift shaft counterclockwise about 45 degrees to find neutral, turn drive shaft and no movement on prop shaft, so far so good. When I attempt to check reverse I had to use pliers to move shift shaft another 45 degrees to reverse gear but it does goes to reverse. Turn drive shaft clockwise in reverse and no movement on prop shaft. I’m attempting to check my work, I don’t have reverse. The purpose of this lower end rebuild was to install all new seals and a new water pump. I did not remove the forward gear or the drive shaft and I didn’t take the bearing carrier assembly apart. The shims that came out of the of the bearing carrier when back in. Further testing- In what I’m calling forward(shift shaft clockwise) I can move the prop shaft in and out about 1/8” and when I pull prop shaft out the 1/8” and turn the drive shaft clockwise I can hold the prop shaft so it won’t turn. By pushing the prop shaft back in the 1/8” and turning the drive shaft clockwise I can’t hold the prop from turning. When I turn the shift shaft 45 degrees to what I’m calling neutral I can see the prop shaft push out about the 1/8” mentioned in the forward gear, no free play in the prop shaft and no turning of the prop shaft when I turn the drive shaft clockwise. If I push the prop shaft down I can feel the spring in the prop shaft assembly pushing back. For reverse after using pliers to full turn the shift shaft fully counter clockwise I have no movement on the prop shaft when I turn the drive shaft clockwise. There is no in and out movement on the prop shaft when in reverse. There is no propeller installed on the prop shaft. Sorry for the long winded post but I’m trying to convey as much information as I can. Thanks in advance for any guidance given to a rookie.

Update: Apparently the bearing carrier wasn’t bottomed out. I gave the carrier a few more taps, not hard just taps and was able to tighten the cover plate a bit more, forward now stays in forward even when I pull the prop shaft out. Neutral is neutral and no movement on the prop shaft when turning the drive shaft. Reverse would not go into reverse since tightening the cover plate so I backed off the cover plate a bit and I have reverse but the shift shaft is very hard to turn fully into the reverse position, so hard that I’m worried that something might break once the lower unit is installed on the engine.

You have to compress a spring in order to shift to reverse.----Takes more effort.-----And you have to turn the prop shaft when shifting from neutral to reverse.

The manual says 60 ft.lbs tork on the bearing carrier nut and using some anti-corrosion grease on threads, if you don't have the tool a Merc dealer or marina should do it for you. "And you have to turn the prop shaft when shifting from neutral to reverse".R.1.

Quicksilver said:

The manual says 60 ft.lbs tork on the bearing carrier nut and using some anti-corrosion grease on threads, if you don't have the tool a Merc dealer or marina should do it for you. "And you have to turn the prop shaft when shifting from neutral to reverse".R.1.

Click to expand...

Thanks, I was looking at “bearing carrier nut” specs. but was unsure if thats what I was after since the Mercury service manual and the parts listing refer to it as “cover”. I made a primitive tool to remove the nut but I won’t be able to use a torque wrench to reapply the nut.

Our nearest big town with Mercury dealer is 200km away so we won’t be there till after Christmas but in the meantime I’d like to be able to test the seals. I should be able to ball park the 60 ft-lbs for purpose of a pressure test?