85HP Mercury Botton End won't go back in

I pulled my lower unit out in the fall to take it in to get the skag fixed along with the prop. I brought the boat home the other day to put the bottom end back in. The motor is a 1975 85HP Mercury.

The bottom end won't go back in, it gets within a inch and will not go back in all the way. I have done this before, and have had no trouble. Have no idea why it won't go back in. It should just pop back in if everything is lined up properly, shouldn't it? I don't want to force in back together. I can tell what is stopping in from going in all the way, I don't know if it's where the shafts line up and the top of the shaft or at the bottom.

Ahy help would be great!!!! Don't really want to take the whole thing apart!!!

Anyone know where you can get free manuals on the internet?

Re: 85HP Mercury Botton End won't go back in

At 1" it's probably the driveshaft spines mismatching are you assm the engine with it in gear so you can turn the driveshaft with the prop.

Re: 85HP Mercury Botton End won't go back in

I always turn the flywheel with my hand until the driveshaft splines match up. The shift shaft splines are a bit more tricky. I put the boat and LU in neutral when assembling. Sometimes you need to rock the shift handle a bit to line it up. Did you put some grease on both splines?

Re: 85HP Mercury Botton End won't go back in

I have put the motor in gear and in neutral, I have tried almost everything. Nothing seems to work. Yes I have put grease on the splines, when in gear you can turn the fly wheel which is turning the prop. But it won't go in the last 1" or so, at one point we had it about 1/4" of a inch to go. Now I can't even do that. On the lower end how would I know if it's in neutral, what position should it be in?

Re: 85HP Mercury Botton End won't go back in

That motor will "Click" and stay in Neutral. Since it doesn't move out of neutral easily, it is easier to line up the shift shafts. You may need to rock the throttle handle back and forth to line it up, if it is a bit off.

Also, there is a plastic fitting that fits around the shift shaft in the midsection. Make sure it is in place as it helps hold the upper shift rod in the center. If you get the motor up to 1/4", look under the carbs and see if the shift shaft has come up.

Re: 85HP Mercury Botton End won't go back in

i actually cant get my bottom end off its all unbolted it only moves down about a 1/8" then no more i tried turnin the motor over and shiftin n stuff but wont come out u have trouble like this ? its a 84 merc 35 horse