Cant get lower unit on after impeller change

[wishn4fishn]

So some place along the lines I have managed to get the lower unit gear out of sync. The shaft won't turn left or righ, when I turn the prop clockwise is clicks and is locked when I try to turn it counter clockwise. I am assuming its not in the correct gear and the splines aren't lining up leaving me about 3/4 of inch from being back together.

Please tell me there is a way to get the units back into the same gear so the splines will. Line up and this stupid thing will go back together BEFORE I need back surgery to repair the damage from lifting it on and off 100 times.

It is a 90 hp sometime in the 80's build.

 

[multimech]

Re: Cant get lower unit on after impeller change

Pull the lower unit off. Use a pair of pliers to CAREFULLY turn the shift shaft until you find fwd gear. You can be sure of this by turning the driveshaft clockwise. The prop will turn clockwise, looking at the prop from the rear. Then shift the control lever to fwd. Install the lower unit. Shift it FNR to check your work.

 

[wishn4fishn]

Re: Cant get lower unit on after impeller change

so to get the shifter to move on the lower unit I have to turn the propeller just a bit to get it to spin. Is that normal? It seems like no matter what I do to the shifter I can turn the rod clockwise or counter clockwise to move the propeller like I could when i was changing the water pump. Is there a trick to get the drive shaft rod to turn again? Its like its stuck in gear, forward I believe, since when I turn the propeller clockwise it clicks and counter is locked.

 

[carholme]

Re: Cant get lower unit on after impeller change

Never mind turning the prop until you have selected a gear by turning the shift shaft. The shift shaft will turn with your fingers about 270degrees in Forward. The way you have described it above, you are presently in forward.Therefore turn it CCW (looking down on the shift shaft) until it stops. Using a pair of pliers to continue rotating the shift shaft CCW just a tad until you feel a positive detent. This will be Neutral, check for free prop rotation in either direction. Using the pliers again rotate the shift shaft while turning the prop CCW just a tad to the next detent and this will be reverse. Ensure the prop does not turn in either direction. Rotate CCW again and you should be back to Fwd where with fingers, you can turn the shift shaft CCW about 270 degrees.

Forward: prop turns CW (ratcheting) will not turn CCW
Neutral: prop turns freely in either direction
Reverse: prop will not turn in either direction

You don't have to use arm pressure to turn the prop, finger pressure is enough.

When this is done and the LU is in Fwd and the boat control is also in Fwd, you have to ensure that you have the reverse lock cam installed properly on the lower shift shaft before installing the LU.


Give me your engine s/n and I'll send you the parts listing if you are not aware of the reverse cam.

Gerry

 

[aussieflash]

Re: Cant get lower unit on after impeller change

Shift lower unit to Neutral,shift control box to neutral,line up drive shaft,water tube and shift shaft.
Once all lined up get someone to move flywheel slightly till shaft slips in.Grease splines but clean off tops of shafts of all grease to avoid hydraulic effect.If your still confused look up some of the many online videos on lu repairs.

 

[wishn4fishn]

Re: Cant get lower unit on after impeller change

You guys are awesome. The gears are all good now everything shifts as it should and I have it ALMOST back on. After turning the flywheel it finally slid in. Now I hit resistance at about a 1/4 inch. Is there anything I should be checking? Or should I keep turning the fly a bit more?

 

[SeaKaye12]

Re: Cant get lower unit on after impeller change

you have to ensure that you have the reverse lock cam installed properly on the lower shift shaft before installing the LU.


Give me your engine s/n and I'll send you the parts listing if you are not aware of the reverse cam.

Gerry

Gerry...is it true that engines that have Power Tilt and Trim typically don't have the reverse lock mechanism?

 

[Chris1956]

Re: Cant get lower unit on after impeller change

Yes, The reverse lock mechanism is not installed on PTT motors.

 

[wishn4fishn]

Re: Cant get lower unit on after impeller change

ok mine does have PTT on it so is there something else to check for if there is no lock mech mentiioned above?

 

[Chris1956]

Re: Cant get lower unit on after impeller change

No, the PTT unit holds the motor down under quick decelleration and in reverse.

 

[wishn4fishn]

Re: Cant get lower unit on after impeller change

Thank you everyone for your help on this. I finally was able to get the lower unit back on and my motor can officially pee again. Turns out, I just didnt have the lower unit level enough to get the last little bit to slide. Once I leveled it out it went right in. I have did a number of impeller changes, not sure what brain fart caused me to have so many issues with this one. Boat ran like a champ once it was all said and done though. Now on to a new post with a new question - not issue.

Thank you all again for sharing your knowledge, it was a big help!!!