1990 OMC Evinrude 20hp refitting gearbox issue

[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

[boats.net]

If shaft was hard to get out then will be hard to get back in, clean splines and grease splines. If wasn't hard to get out then splines must not be aligning up.

[boony_124]

I had used WD40, oil and greased the splines. On a long rod raped a chucks cloth and cleaned bottom of crank as best as I could. With a small screwdriver scraped every spline clean on the driveshaft.

With clean oil on the splines then after trying to get it in. Can pull it out and see the witness marks of the splines engaging just over half of the spline space. So just over or pretty close to 1".

I took it into local boat shop and they called me up stating the driveshaft is faulty. Something with splines or cracking. Not sure if thats the original problem or caused by me but as long as they get it in. All will be good.

Cheers,
Jason

[phillnjack]

the splines are not lined up its that simple.
when you say it turn the prop over, then get someone to hold the prop real tight, then someone else turn the flywheel.
all at the same time try to lift the gearbox up and it will pop in place.
Ive seen this happen a lot on engines, its just a very good / tight spline fit with no sloppiness.

give it a try

phill