Compatible Mercury lower units

[firenfix]

New here....I just bought a boat with a 1988 35HP Mercury tiller. Removed the lower unit and it seems like the lower unit is stuck in reverse.Seller stated that it needed an impeller and was not sure about shifting. May need to buy a used lower unit and I am wondering what years/models might also fit the 1988? Thank you, Mike

 

[racerone]

Do your trouble shooting.--------Rare for those to be stuck in reverse !

 

[firenfix]

I really am not sure what else to do. Drive shaft seems fine, pulled the shift gear out and put back in, same result. Prop shaft seems to spin without any resistance, just cannot rotate the shift gear do disengage revers. With enough pressure on the gear I can get the shaft to spin in reverse but it has clearly not engaged completely and goes right back to reverse when I let off pressure. Do you know if a mid seventies 40 HP lower unit would fit, might be able to get one cheap. Thanks, Mike

 

[racerone]

Serial # is ?---Which way are you turning the driveshaft to determine it is stuck in reverse ?----You should not be able to pull the shift rod out of the lower unit.-------So is it stuck in forward , reverse or you are not sure ?

 

[firenfix]

0B357272. Turnig prop shaft clockwise it ratchets if I hold the driveshaft. Turn the diveshaft CC and hold the prop shaft the drive shaft ratchets. Turn driveshaft clockwise, prop shaft turns clockwise. I pulled the shift rod out after unscrewing the threaded part on top ( dont know the name).

 

[racerone]

Thought so. ----It is stuck in forward and the ratcheting in forward is normal.--------You might need to take lower unit apart to install shift rod in the cam !

 

[firenfix]

How hard would it be to replace that cam? What do you think it would cost to have someone else repair it?

 

[racerone]

I guess that depends on what tools are in your workshop.--------I say it is easy.-----Others will argue.

 

[jimmbo]

Looking at the bottom of the picture of the shift shaft. is that 1/2 of the nut that holds the bearing carrier in the gear case?

 

[firenfix]

No nut, just clean shaft. When I look down to the cam I see a couple numbers stamped in a piece of metal, if that's the cam' can I manipulate into the right spot and slide the shaft back in?

 

[racerone]

You can try.----It only fits one way I believe.

 

[firenfix]

No Title

OK, got it apart and the gears all look good to me. There was a loose pin by the cam, any idea where that goes? Also, any washers, spacers, etc. associated with the cam and how should it be positioned? Thanks, Mike

 

[racerone]

The pin rides on the cam.----The pin goes in the end of the shaft.--You hold it in there with some grease.---Pointy end stick out.---I believe you decided that it was stuck in reverse when it was just in forward because clutch dog is spring loaded !---Removed shift rod for some reason !-----There was nothing wrong with this unit in my opinion.---The parts all look like new !

 

[firenfix]

No Title

Not sure how the cam got stuck but it did. Managed to get the shift shaft back into the cam with the most pronounced part of the cam facing the prop? It now turns smoothly with the shift shaft assemble installed. Slid the prop shaft assemble in place (did not tighten with nut) and the shift rod and cam won't turn? Any idea what I'm doing wrong? As soon as I slide the prop shaft assemble back out, shift rod and cam are free again. Also, I was able to remove the prop shaft assembly/carrier by using an inexpensive gear puller swapping out the arms for 2 eye/hook turnbuckles from Lowes. Worked well for me, hopefully it will help someone else.

 

[racerone]

It takes some effort to turn the shift rod , vice grip required to turn it CCW to get nuetral and a little more for reverse.----Note the strong spring inside the propshaft!----I do not believe this lower unit was stuck at all.

 

[firenfix]

Could I have the cam misaligned?

 

[racerone]

No you can not !------Very top of this page is some info for you on how to install one of these lower units.------One more time.----- I do not believe there was anything wrong with this unit.--------Just the former owner was a not a mechanic who understood fine machinery.

 

[firenfix]

No Title

OK, was able to turn with vice grips, thank you. I was not able to turn with vice grips before so something good happened! I did notice in the engine compartment, there is a piece of the shift lever that goes to a cable broken off? The handle and mechanism see to shift just fine?
In any even, thank you again for your help!

 

[firenfix]

I think I need to quit using the speak to type feature on my phone.....

 

[merc850]

That looks like the lever that turns the shift shaft and it's broken where it attaches to the shift cable, this is your problem.
Find the serial Nr. and look for the upper shift shaft here http://www.marineengine.com/parts/mercury-outboard-parts/