Trouble fitting gearbox into 20hp 1990 OMC Evinrude

[boony_124]

Hi there I have replaced my water pump on my 20hp OMC Evinrude.

However I CANNOT get the gearbox to go back in.

I need to line up water tube, shift linkage is easy and it is a lock nut with the keeper in the water intake. Driveshaft spacer is not fouling. The water tube isn't fouling as it just about to enter the rubber seal but still loose.

The top of the driveshaft IS engaging the splines. Can turn motor and gearbox/prop over. With grease/oil on top splines can see it going into bottom of flywheel by approx 1"

However the gearbox still need to go up by another 1". Still not enough to even get the bolts started. I have put long rod with cloth to clean out any grease that could cause hydrolock. However looking up exhaust housing looks clear. When pushing gearbox up can feel like it is hitting the bottom of flywheel. I even removed the shaft just by itself and trying to tap it in further however it won't go in any further.

I am lost atm.


Any ideas as to why it simply won't go all the way in? Or any ideas/methods?

Regards,
Jason
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[steelespike]

Re: Trouble fitting gearbox into 20hp 1990 OMC Evinrude

Just so we all understand the driveshaft spline goes into the bottom of the crankshaft.The flywheel is on the other end of the motor.
My first guess is that somehow you pulled the drive shaft out of the gear case.
Speaking generically;
if that is the case it would seem that the impeller pin/key won't line up with the impeller when its in the housing.

 

[jeffersondodson561]

Re: Trouble fitting gearbox into 20hp 1990 OMC Evinrude

With grease/oil on top splines can see it going into bottom of flywheel by approx 1"

If you put grease on top of the drive shaft and not just on the splines you may be experiencing hydro locking the drive shaft into the coupler.

 

[kenmyfam]

Re: Trouble fitting gearbox into 20hp 1990 OMC Evinrude

You are not properly aligned with the splines. 1 inch should be around the amount of engagement there.
You will know when they are properly aligned and the relief will be wonderful !!!!. Are you attempting this by yourself ?? if so I suggest a helper.
But whatever you do..........Do Not think that it is all aligned and try to pull it up on the bolts if there is still a large gap there. Things become bent and broken when that method is used.
Just y thoughts on this at this time.

 

[steelespike]

Re: Trouble fitting gearbox into 20hp 1990 OMC Evinrude

You are not properly aligned with the splines. 1 inch should be around the amount of engagement there.
You will know when they are properly aligned and the relief will be wonderful !!!!. Are you attempting this by yourself ?? if so I suggest a helper.
But whatever you do..........Do Not think that it is all aligned and try to pull it up on the bolts if there is still a large gap there. Things become bent and broken when that method is used.
Just y thoughts on this at this time.

He says it engages the crank about 1" but 1" space remains.
says he cleaned out excess grease.Is there only one way the spline will fit?

 

[boony_124]

Re: Trouble fitting gearbox into 20hp 1990 OMC Evinrude

You are not properly aligned with the splines. 1 inch should be around the amount of engagement there.
You will know when they are properly aligned and the relief will be wonderful !!!!. Are you attempting this by yourself ?? if so I suggest a helper.
But whatever you do..........Do Not think that it is all aligned and try to pull it up on the bolts if there is still a large gap there. Things become bent and broken when that method is used.
Just y thoughts on this at this time.

The reason I am quite certain it engages the splines as I can feel it engage then slide up an 1". The if I turn the motor over by hand the prop turns etc, if I turn the prop I can turn the motor over, etc. However without being able to see I can't be 100%

I ended up taking it into the shop. They said the driveshaft splines are cracking or something and are going to replace the shaft and fit it up. Not sure if this is the case but as long as they get it in. All will be good.

 

[kenmyfam]

Re: Trouble fitting gearbox into 20hp 1990 OMC Evinrude

The reason I am quite certain it engages the splines as I can feel it engage then slide up an 1". The if I turn the motor over by hand the prop turns etc, if I turn the prop I can turn the motor over, etc. However without being able to see I can't be 100%

I ended up taking it into the shop. They said the driveshaft splines are cracking or something and are going to replace the shaft and fit it up. Not sure if this is the case but as long as they get it in. All will be good.

Glad you are getting it sorted.
Wouldn't line up correctly due to broken / cracking splines eh ???