Hosed my lower unit

[bh357]

I was backing away from the dock, and went to shift into forward. It didn't shift into forward, and I heard s metallic ratcheting sound. Got the boat onto the trailer and dropped the lower unit. If I turn the prop one way, the driveshaft turns one way. If I turn the prop the other way, the driveshaft turns the other way. There is no freewheel on the prop if you try to turn it backwards. Motor is a 1963 Merc 1000 inline 6<br />Thanks for your help.

 

[KCLOST]

Re: Hosed my lower unit

That doesn't tell us much... Just that is appears to be in either forward or reverse gear...<br /><br />But if it won't go, it may be torn up...

 

[mcginleyc]

Re: Hosed my lower unit

Bh, It is tough to say what the extent of the damage to the lower unit is without pulling the lower unit housing out and inspecting the gears. A more revealing indicator would be to drain the l/u oil and inspect for "chunks" or large filiings. If these are present there is definitly a rebuild in the future. Forward and reverse gear are always moving in the lower unit and are attached to the pinion gear. This is why the driveshaft turns the opposit direction of the propshaft. Also if you rotated the driveshaft in a counter clockwise direction you will have to inspect the water pump impeller. Do this could have damaged the vanes. They are set to a clockwise posistion. Good luck

 

[Stefan Schmitt]

Re: Hosed my lower unit

I believe Mercs rotate freely both ways when shift in neutral. When in forward it rotates freely one way and blocked (i.e. in gear) the other. When in reverse, it is blocked both ways - just as you described - that is, with the l/u off the crankshaft would rotate both ways.<br /><br />In other words, your engine is stuck in reverse. Just for grins, check under the cowling and see if the shift assembly is still intakt. If so, just shift gears and observe if your shifter is moving that part. If not, your problem might not be the l/u but rather your shifter, or the cable to it. It might have come loose. If none of the above then:<br /><br />Take the l/u oil out and check for water and metal shavings. If you have water..then metal shavings wouldn't be suprising, since this is an indicator that your l/u seals are bad and probably caused your gears to be eaten up. - At that point...well...let's just say that's not good news.<br /><br />For expert advice go here: www.themarinedoctor.com

 

[bh357]

Re: Hosed my lower unit

I drained the lower unit and the lube looked creamy, but with no beaded water. There wrere no metal shavings in the lube, which I guess is good. I tried turning the shift shaft with a pair of pliers, but it won't turn at all. The shift mechanism on the motor functions properly. The motor is stuck in a gear but with no freewheel, almost like it's a direct drive unit.<br />Before this happened, I was having some issues with the shift mechanism not shifting all the way forward (i.e. not enough to allow the throttle to fully advance).<br />The motor was backing up just fine, just heard a ratcheting type sound when I gave it a little throttle. After that, it wouldn't shift into forward.<br /><br />Thanks for the advice so far.

 

[KCLOST]

Re: Hosed my lower unit

Bad news............<br /><br />If you can't get the shift shaft to turn with pliers, you have a gear problems, assuming you removed the shift linkage prior to trying this????? I just want to make sure you did disangage it...<br /><br />If you didn't, I wonder if you have some problems with the cables....<br /><br />Pull the lower unit and see if you can turn the lower shaft ok,,,, It kinda sounds like its gonna have to be pulled anyway.. So it's worth a check..

 

[bh357]

Re: Hosed my lower unit

Thanks KCLOST,<br /><br />I believe the cables are ok. They slide freely when disconnected. Also, the shift linkage in the motor and the leg functions fine. I tried turning the shift shaft on the gear housing with a pair of pliers and it will not turn. It almost seems like the lower unit is in gear, with no way of shifting out of it. Also, the freewheel mechanism is not working (if you try to turn the prop backwards with the gearshift in forwards for example, it would turn and click and not turn the driveshaft). Now it turns the driveshaft backwards.

 

[bh357]

Re: Hosed my lower unit

I pulled the shift shaft bushing today after work, and the shift shaft is off center in the opening. It is somehow being forced on an angle with the top end towards the water pump (aft). When I replaced the shift shaft bushing, the shift shaft was straight and centered in the opening. I'm attempting to remove the bearing carrier, but can't get the bearing carrier retainer ring off. The manual references a special tool, which I don't have.<br />Any help would be greatly appreciated.

 

[mcginleyc]

Re: Hosed my lower unit

bh, I am not familiar with that motor, but I know on Mercurys and others there is a ring that screws against the l/u bearing carrier. It comes out as usual in the counter-clockwise manner. There is probably a "key" on the bottome side of the bearing carrier housing that needs to be removed before pulling the bearing carrier housing. This key keep the housing from turning in the case. Try to get some two or three jaw pullers from someplace like napa. They will have a slide hammer and will enable you to remove the housing. Good luck

 

[bh357]

Re: Hosed my lower unit

I broke down and drilled and broke out the retainer ring. I was able to do this without damaging the threads. However I am not able to remove the bearing carrier assembly and propshaft. I tried the procedure in the (OEM) manual, which is as follows: grip propshaft between two blocks of wood in a vice, and tap lightly on the skeg to slide the carrier assembly out. Well, tap lightly turned into whack the living you know what out of it, but no movement. I even tried liquid wrench to help loosen things up.<br />I am reluctant to apply heat to the housing, but I will as a last resort. Would a gear puller, forcing the bearing carrier to move with respect to the propshaft work? According to the manual, the propshaft and bearing carrier come out as one assembly.<br />Thanks

 

[Chris1956]

Re: Hosed my lower unit

BH- It has been my limited experience that the bearing carriers are very difficult to remove. I used a harmonic balancer puller with "Hook bolts" on an '73, 85 HP lower unit. (The bearing carrier was designed to slide over the prop shaft)It still took a sledge (on the puller) to persuade the carrier to come out. I have been advised that you need a puller and gentle heat on the aluminum housing to remove it.

 

[Bob La Londe]

Re: Hosed my lower unit

Another option that may be cheaper or less hassle. Visit your local marine dealers and ask if they have a motor with a compatible lower unit, but a blown power head. I recently got a complete motor to take the lower unit off of for my Force 50 for less than the price of the parts to rebuild my lower unit. In additon to a complete working lower unit I got complete electronics, carb, etc... all in better shape than mine. The dealer who sold my the donor motor may have given me a deal on it since he sponsors me in the local bass tournaments, but its still an option to check.

 

[mcginleyc]

Re: Hosed my lower unit

The probability of you finding that exact lower unit is not great. Even if you do It will be 40+ years old. Try to get a "jaw puller". They have a weight that is attached to the jaws on a metal shaft. It will remove the housing. Also applying heat in the right manner will not damage anything. Use a propane torch or MAP gas torch. These two will not melt the alluminum housing. A oxy-acetelene torch can melt the bullet of the lower unit into a glob if not used correctly. Go with propane and heat it up pretty good. Remember it will come out. good luck

 

[Bob La Londe]

Re: Hosed my lower unit

Perhaps, but there are a lot of old inline sixes out there.

 

[bh357]

Re: Hosed my lower unit

Bob,<br /><br />Do you know which lower units would be compatible with my motor? I found a shop with what I believe is a mid~late 60's Merc 650 (4cyl version, not the 3cyl), with a bad ignition. He told me $200 would take the whole thing (bad ingition and I believe it's also missing the tilt tube and upper cowl).

 

[Bob La Londe]

Re: Hosed my lower unit

I have to be honest at this point. I do not know which ones would be compatible. If it is a shop that has been around a while he should know if it is compatible. Ask him if you can bring it back if it doesn't fit.

 

[Bob La Londe]

Re: Hosed my lower unit

P.S. a lower unit froma much smaller motor doesn't seem likely to be compatible in my opinion.