Mercury Midsection Spacer

[Barth]

Ok, I shelled my 1996 Mercury Lower unit. I took it off and can not remove the gearbox. So then I took it to a Local Marine dealer for some help. We worked on it together and it just won't come apart. The motor came from the ocean. Long story short, I have decided to buy a used Lower unit for my motor now. But am having trouble finding a 25" 3 Jaw used lower unit. My boat really doesn't need the extra long so I thought I might be able to buy a 20" lower unit and remove the 5" spacer from the midsection. I know I will have to remove the power head to change the shifting linkage to a 6 jaw. But will there be anything else I will need to do to the motor besides removing the spacer to make the shorter lower unit work? I have searched the internet for the last couple days and can find lots of information on putting a longer lower unit on a motor but nothing on doing the opposite. Any help would be great. Thanks

 

[Dukedog]

what motor?

 

[Barth]

115, offshore, sorry

 

[Dukedog]

ya can leave me in tha truck with tha in-lines, sorry......

 

[Chris1956]

I did that conversion on a Merc V6. The spacer on that motor did not have any bolts of it's own. All the bolts were 5" longer in the midsection and gearcase, and passed thru the spacer. I had to remove the spacer, change the studs on the midsection, and install the 20" gearcase. I cannot guarantee your configuration is the same.

You really need to be able to drop the current gearcase or your project cannot proceed. Are the driveshaft splines rusted to the crankshaft?

 

[Faztbullet]

You will also need to remove powerhead to replace shift rod and remove and replace studs in midsection....

 

[Barth]

I have the lower unit removed. I am talking about the gearbox inside the lower unit. I know I the gears are bad from when I drained the lower unit gear oil, I had gear teeth from both the pinion gear and either reverse gear or forward gear. Motor really doesn't like to go into reverse at 30 mph.

 

[Chris1956]

Fazt, when I did the conversion from 25" with spacer to 20" w/o spacer, the gearcase had the longer driveshaft and shift shaft. It that a providence of the V6 motors?

 

[Faztbullet]

The 3 and 6 jaw lower units have a different throw length on the shifter rod only on the 3/4 cylinder motors..

 

[Barth]

Now my problem is, the water tube is to long. I can figure out how to remove it. I know it will turn but it will not pull down. I need to shorten so the new lower unit will fit. How do the water tubes remove? I know once I can remove it I can just us my tubing cutter to shorten the old tub. They are just a copper tube.