# Can't drop gear case to change impeller on Tohatsu 6HP



## gallilaw (Mar 2, 2010)

I need to change the impeller on my 2-year-old Tohatsu 6HP SailPro. 

I have the Service Manual and have followed the instructions. 

I removed the rubber grommet and loosened the shift rod joint bolt, and the two rods can now move independently and freely.

I have removed the two gear case bolts.

I have tried many times to pull the gear case assembly down to gain access to the water pump, but each time it remains firmly attached, almost as if the drive shaft was bolted to the engine.

I can wiggle the gear cases assembly freely; I just can't get it to drop. 

I have used my hand to slam it down, and have tapped it with a hammer, using some wood as a buffer to avoid metal-to-metal contact.

Because my SailPro is a long-shaft, there is a large cast spacer that connect the gear case assembly to the drive shaft housing. I have tried to free up the gear case assembly by disconnecting the bolts that hold the spacer in place. No change; the gear case assembly won't drop.

I have tried turning the engine to move the drive shaft but that doesn't help either.

I am afraid if I hit the gear case assembly any harder I will wreck the motor.

Any advice?


----------



## deniseO30 (Nov 27, 2006)

I can't help you specifically but there's a forum you could join. 
Honda & Tohatsu/Nissan Outboards

and a link for pdf manuals
http://www.tohatsu.com/tech_info/manuals.html

Some have bolts upside down holding lower case on. Others are really really difficult with the linkage. Hope the link helps.


----------



## overbored (Oct 8, 2010)

on the earlier models there is a shift linkage that has to be disconnected for the case to come down. and every time i do it i forget until the light goes.


----------



## capecodda (Oct 6, 2009)

On a much older yamaha I had one stick like this even with everything disconnected. Needed to wedge it with screw drivers and whale away with a hammer. 

I wonder since it's relatively new if even the paint at the lower unit junction is holding it? Just a guess....if thats it might be able to get a sharp knife in there and break it.

The designers of outboards couldn't have made changing a water pump impeller harder if they tried!


----------



## dabnis (Jul 29, 2007)

Try this one, I have the same motor, standard shaft, I will see if I can find any "hidden" bolts.

2011 MFS6C Tohatsu Outboard GEAR CASE, DRIVE SHAFT & GEAR CASE, PROPELLER SHAFT Diagram and Parts

Paul T


----------



## misfits (Dec 9, 2011)

Dabnis, God love ya !

LETS GET SERIOUS ABOUT CRIMINAL CONTROL NOW


----------



## dabnis (Jul 29, 2007)

misfits said:


> Dabnis, God love ya !
> 
> LETS GET SERIOUS ABOUT CRIMINAL CONTROL NOW


I am trying, but there are a lot of people against me

Paul T


----------



## dabnis (Jul 29, 2007)

dabnis said:


> Try this one, I have the same motor, standard shaft, I will see if I can find any "hidden" bolts.
> 
> 2011 MFS6C Tohatsu Outboard GEAR CASE, DRIVE SHAFT & GEAR CASE, PROPELLER SHAFT Diagram and Parts
> 
> Paul T


On mine, the only bolts I can see are bolts 53 & 55. There is a member by the name of pvann---? who is a Tohatsu rep. He may be able to help you, or maybe your local dealer could tell you what the trick is?

Paul T


----------



## macwester26 (Mar 21, 2013)

dabnis said:


> On mine, the only bolts I can see are bolts 53 & 55. There is a member by the name of pvann---? who is a Tohatsu rep. He may be able to help you, or maybe your local dealer could tell you what the trick is?
> 
> Paul T


Is there an anode ? if so removing the bolt may help you Some outboard engines have the anode bolted on the bottom of the shaft...and this also holds the shaft in...


----------



## dabnis (Jul 29, 2007)

macwester26 said:


> Is there an anode ? if so removing the bolt may help you Some outboard engines have the anode bolted on the bottom of the shaft...and this also holds the shaft in...


Good point!! Yes, there is one on the housing just above the cavitation plate, I think. I guess the best approach may be to remove anything you can get your hands on. I would, however, leave the driveshaft in the gear box housing. Not sure if things would fall in to themselves if you take it out, but wouldn't want to find out the hard way.

Paul T


----------



## gallilaw (Mar 2, 2010)

Finally got it apart. It took an unbelievable amount of force. I actually snapped a pry bar. Used a heavier pry bar, applied more force than I want to remember, and the drive shaft finally released. Put in a whole pump repair kit, not just the impeller.

After all the time and effort getting it apart, I forgot to care about the gear sync when I put it back together. Now all the parts are assembled and I don't know what direction the clutch cam is pointing, what gear it's in currently, or whether the cam rod and the shift rod are properly set up at the shift rod joint.


----------



## capecodda (Oct 6, 2009)

If it's like other small outboards I've worked on, you can mess with the shift rod adjustment till you get it right. Disconnect the spark plugs so you're sure it won't start, then try different shift rod adjustments. When it's in gear forward and reverse, you shouldn't be able to easily turn the prop by hand (cause of engine compression). When in neutral, it should spin freely. You probably are close to the right setting if you get neutral in the middle setting, and the prop doesn't easily turn in forward and reverse. Once you've got it adjusted as above, then put it in the water and fire it up and see if it works in all 3 positions. If you hear it slipping or not fully engaging, try again....

Not sure this is the best way but it's worked for me. Good luck!


----------



## dabnis (Jul 29, 2007)

gallilaw said:


> Finally got it apart. It took an unbelievable amount of force. I actually snapped a pry bar. Used a heavier pry bar, applied more force than I want to remember, and the drive shaft finally released. Put in a whole pump repair kit, not just the impeller.
> 
> After all the time and effort getting it apart, I forgot to care about the gear sync when I put it back together. Now all the parts are assembled and I don't know what direction the clutch cam is pointing, what gear it's in currently, or whether the cam rod and the shift rod are properly set up at the shift rod joint.


Oh, dear!!, if you took the drive shaft out of the gear box you may have a problem. My experience was with OMC motors, so have no hands on experience with the Tohatsu. You might try gripping the shift rod and push it as far down as it will go. Then pull the engine over to see which way the prop turns. Then adjust the shift lever accordingly.

Paul T


----------



## gallilaw (Mar 2, 2010)

Problem solved (I think). I took the lower rig apart once more to make sure that the cam rod was turned in the correct direction. I pressed it down to seat it in the reverse position. 

After wiggling the drive shaft and cam rod into position, I tightened the lower unit to the shaft housing. The gears were still messed up. I used a big handle from a socket wrench to put force on the end of the cam rod that exits the shaft housing at the upper end, near the engine. Plunk. It dropped another inch. That seated the cam shaft one notch lower, to the true reverse position. At that point I tightened the cam rod clamp and all the gears were working again.

I hope it works as well when I turn the power on, some time tomorrow.


----------



## dabnis (Jul 29, 2007)

gallilaw said:


> Problem solved (I think). I took the lower rig apart once more to make sure that the cam rod was turned in the correct direction. I pressed it down to seat it in the reverse position.
> 
> After wiggling the drive shaft and cam rod into position, I tightened the lower unit to the shaft housing. The gears were still messed up. I used a big handle from a socket wrench to put force on the end of the cam rod that exits the shaft housing at the upper end, near the engine. Plunk. It dropped another inch. That seated the cam shaft one notch lower, to the true reverse position. At that point I tightened the cam rod clamp and all the gears were working again.
> 
> I hope it works as well when I turn the power on, some time tomorrow.


I see, I think When you get it on the boat, suggest you put the power to it very easily and slowly. If it stutters or jumps out of gear more adjustment may be necessary.

Paul T


----------



## capecodda (Oct 6, 2009)

When it comes to fixing stuff like this, trial and error has always worked for me....mostly

Good going!


----------



## dabnis (Jul 29, 2007)

I kind of got lost in your description of the linkage. If all you did was to disconnect the coupling, I would think just re-coupling it with the original marks would do it? However, if you took the drive shaft out of the gear casing, that may be another story? Pictures?

Paul T


----------

