Shifting Problems / Lower Unit Problems

[myfirstboat1984]

I have a 1984 Wellcraft, with a mercusry mercruiser inboard/outboard, 4 Cyl, 140 HP, 3L Engine. Several times over the last couple months, the boat has slipped out of gear. Before, I was able to get it back in gear, but this time, I was not. I am not able to get any forward or reverse now. Here's what I know...

-Drained oil. There are small medal shaving in oil. Enough to be noticable. This oil was changed a month ago.

-With engine on, from control panel, shift to foreward or reverse, and there is absolutely no gear sounds at all. No grinding, but the shift cable is moving and the linkage is intact all the way to the lower unit.

-With the engine off, shift to forward. I cannot turn the propellor in the reverse direction, but I can turn it in the foreward direction easily. When I do, there is a click noise about midway up the lower unit.

-with the engine off, shift to reverse. I can turn the prop both directions easily, and the click mentioned about doesn't happen, but there is some very slight clicking at the lower part of the unit, near the prop.

- Maybe related?? The empellor is no longer pumping any water through the engine (using muffs).

Any thought are welcome.

 

[SS MAYFLOAT]

Re: Shifting Problems / Lower Unit Problems

I would drain the oil and pull off the lower unit. There are splines on the top of the shaft. It is possible that they have sheared off or the splines in the upper unit have sheared. If so, this is why your water pump may not be working as that shaft turns the pump. This would also cause shifting problems. At least that is my unexperted opinion .........SS

 

[myfirstboat1984]

Re: Shifting Problems / Lower Unit Problems

Forgive the dumb question... The lower unit seems to be in two parts. There's the part actually attached to the boat, then there's the part with the propellor on it. About 1/3 to 1/2 way down the lower unit, there's several bolts that would allow the unit to come in half.

Which do you mean when you say "remove lower unit"? I'm guessing it's the entire thing, and not just the lower half.

 

[SS MAYFLOAT]

Re: Shifting Problems / Lower Unit Problems

The part that holds the prop is known as the lower unit. Just above the prop, the lower unit will separate from the upper unit. The upper unit is bolted to the gimbal housing which is bolted to the transom. Before doing anything, you should have a manual and be mechanically inclined. First thing would be drain the lube from the outdrive as you will have a mess if you don't.

 

[myfirstboat1984]

Re: Shifting Problems / Lower Unit Problems

Thanks for the definitions. It helps so much to know that. A big challenge to getting help online is not being able to explain things as you are pointing to them. I have the manual, but I don't always have good luck finding what I need there. I'm machanically inclined, but a complete novice with boats. I do have the diagrams of the lower unit, and I'll study up on that.

I hear that after removing the lower unit, getting it back together in just the right way can be a bit challenging, and can cause damage if not done right. I've drained the oil already. I'm going to remove the lower unit and see what it looks like. Maybe I'll see something worth posting back here. The worst that can happen is I take the pile of parts to the machanic in defeat.

I'll let you know what happens, Thanks!

 

[myfirstboat1984]

Now Removing Lower Unit (Shifting Problems / Lower Unit Problems)

Now Removing Lower Unit (Shifting Problems / Lower Unit Problems)

Okay, I've studied the manual for removal, disassembly, reassembly, and installation of the lower unit. My first goal is to get the unit off and see if there's anything obviously wrong, without disassembling the entire lower unit..

A few questions before I remove a single bolt...

Does it matter whether I remove the lower unit while in forward, reverse, or neutral?

I have seen people that build a wood stand to hold the lower unit upright, but is this worth the trouble for me, especially since I don't know if I'm going to even be working on it yet? For now, I just want to take it off and look at it. I wondered if it's so heavy I would regret not having it in a stand?

Thanks!

 

[SS MAYFLOAT]

Re: Shifting Problems / Lower Unit Problems

When removing the whole outdrive unit from the gimbal, the shifter must be in forward position. While removing the lower unit (which will remove half the weight from the whole thing) it does not matter where the shifter is. On the gimbal assembly, there is a shoe that fits the foot that is attached to the lower unit. When dropping the lower unit, the foot will drop out of the shoe of the gimbal assembly. The reason why it is important for the shifter to be in forward gear during the whole outdrive removal is that that foot and shoe have to be pointed forward for it to slide out of during removal. In reverse or neutral, the shoe/foot will be slightly turned which will keep the unit from sliding off of the gimbal unit.

Do be prepared as the outdrive is heavy. Lower unit is about 40 to 50 pounds as is the upper as well. If you work on them often, then a stand is nice to have. If you have someone that can help does make things a bit easier. A supply of wood blocks of different sizes helps to block things up.

With metal shavings in your oil is a good indication that something has let loose in your lower unit.

 

[frank246]

Re: Shifting Problems / Lower Unit Problems

You can also try this one first before tearing it down,
Engine not running.
Remove the shift cable comming from the throttle lever of its outer cable stud on the shift linkage plate. (where shift cable is attached in the engine comp.)
Now, only the (black) lower shift cable is still attached, move the lever so the cable pulls, thus shifting the o/d in reverse.
Try if you can turn the prop counterclockwise (clicking) but in clockwise it locks up.
Now shift the lever so the cable pushes in, the o/d should shift into fw so you cant turn the prop counter clock wise but only clockwise with the clicking noice as you described. Try this also with the engine running and the ear muffs hooked up the garden hose on the water intakes on the lower first!
When the o/d shifts, the shift cables needs to be adjusted on the shift linkage plate and mostly the lower shift cable is binding so the clutch dog does not fully engage.
It can be worse though like e broken shaft but better be sure before turning the nuts. The little pieces of shavings can be from the clutch dog not engaging complete as long as there are no bits.
How to, search for Mercruiser shiftcable adjustment.
If the engine turns the prop in the water the waterpump needs to be replaced asap. (New post)
Be carefull!