Lower Unit Binding?

[McGR]

After discovering milky lower unit lube, last night I pulled my lower unit on my '76 Johnson '85hp to replace the prop and driveshaft seals and perform a subsequent pressure test. After installing the new seals, I noticed that the driveshaft seemed like might be taking excessive force to turn, even with the waterpump removed. I can't turn the driveshaft with one hand. I can turn the driveshaft with two hands or with a channel lock pliers. Is this sort of resistance to turning normal for this type of lower unit? This lower unit is a hydraulic/mechanical type as opposed to purely mehanical, so it pushes a pump in addition to the gears. Nonetheless, it seems to me the force required to turn is excessive. I hope I'm wrong. Is there possibly some sort of torque spec. for the force required to rotate this lower unit? <br /><br />Any input is greatly appreciated.

 

[marinemech]

Re: Lower Unit Binding?

with out water pump drive shaft should turn freely i suspect a part has not been installed correctly or at all good luck

 

[ob]

Re: Lower Unit Binding?

Are you trying to turn it in or out of gear?In gear will be harder and if you can rotate it using both hands ,baring in mind the diameter of the driveshaft in relation to the pinion and forward and reverse gears,I'd guess your ok.I would however flush the lower unit if the old oil was milky as The case may have a significant amout of emullsified lower unit lube splattered against the inside of the gearcase.

 

[rodbolt]

Re: Lower Unit Binding?

hello<br /> without a water pump it should take two fingers to rotate either shaft. find the problem<br /> good luck and keep posting

 

[McGR]

Re: Lower Unit Binding?

I can rotate the prop shaft with my pinkie finger. However, the driveshaft is a different story. Is it possible I'm just noting the resistance of the hydraulic pump?

 

[McGR]

Re: Lower Unit Binding?

OK... If nobody tells me otherwise, I'm going to start tearing into it tonight. Any final opinions regarding my situation before I pass the point of no return?

 

[McGR]

Re: Lower Unit Binding?

Situation update...<br /><br />I was a little tentative about tearing into my LU initially because I ran the motor last Sunday with no noticeable problems. But between the advice given here and my gut, I decided to go ahead and proceed into the unknown. It's a good thing I did. I finished completely taking apart the lower unit today and found what I thought may be the perpetrator, the hydraulic pump. Apparenlty, somehow the screen was damaged allowing debris to enter the pump. This was causing binding in the pump. Other than that everything else looks OK. I took apart the pump and cleaned it out. After a good cleaning the binding ceased. So, I guess I need to find a screen for the pump... if they are still available. I've heard it mentioned that these type gearcases can be converted to purely mechanical. Would this possibly be a better option?

 

[McGR]

Re: Lower Unit Binding?

I feel like I'm hogging my thread... Hopefully others can chime in soon regarding my questions...<br /><br />Anyway, another update... I ordered $150 worth of parts this morning to fix the hydrualic pump. After getting back from the marina, I inspected the parts I pulled out of the lower unit and analyzed how this gear system works. In observing the system, it appears to me that removing the gears from the inside of the pump would disable the pump. However, the mechanical portion of the shift would be still be functional. Could it possibly be this easy to convert this? If it is, I'm wondering if this is possibly a better way to go in the long run. <br />Because:<br /><br />1. I don't have to spend the $150 for parts. (I should be able to cancel my order if necessary)<br /><br />2. It's one less thing within the lower unit to go wrong.<br /><br />Any opinions on this would be greatly appreciated.