changing lower gear lube on force 125hp

[b-man]

Hi there,
I getting to prep for winter and going to change my lower unit grease, I have a 86 Focre 125hp o/b. On this motor the drain plug is at bottom of unit much like a little screw. My question is the plugs, they are next to each other, unlike the top /bottom. I know I fill it thru the fill side to come out the vent side.But mine is not marked, was told the Fill side is the one in front, near the boat, is this correct?
About how much does it take to fill also? Thanks for the help

 

[Shifflett115]

Re: changing lower gear lube on force 125hp

the vent screw is the farthest one from the boat ,the drain plug is a little allen screw at the very bottom of the lower unit ,there is also a flat head screw on the side at the bottom ,DONT TAKE THAT ONE OUT that is for the shift fork but as for the two screws at the top ,the one closest to the boat is the fill, the one farthest from the boat is the vent

 

[Frank Acampora]

Re: changing lower gear lube on force 125hp

We'll go back to basics firse.

With the engine vertical, remove the drain plug and both fill and vent plugs. Let all the oil drain.

Replace the drain plug after first coating it with teflon tape or anti-seize compound.

The forward plug is fill and the rear plug is vent. So, fill through the forward plug until oil comes out the vent. Let the engine stand vertical for about 1/2 hour to let all air rise then top off again until oil comes out the vent. This ensures that the top bearing gets oil. Takes somwhere around a quart. I don't know exactly because I pump mine from bulk.
Now, here's the reason you fill that way: The front plug communicates with a large chamber running all the way down to the gearcase torpedo behind the forward gear, the rear plug opens into the top bearing space. While it is possible to fill from this plug, you would be forcing oil, not air through the top bearing and a small vent hole low by the bottom bearing. This is difficult. You might think you have it full when in actuality it might not be. The top bearing would run without oil----You know the rest---

 

[b-man]

Re: changing lower gear lube on force 125hp

Thanks you both for the help, much appericated. I bought this boat this past spring and only had it out a few times, but wanted to prep it for winter and p.m. on it so I now it been done and what shape it is in.

On one more help question, just recently put on a new trim motor, got it on okay, put some fluid in but ran out, so went got some a few days later was not using boat at time. I noticed that I have a small drip of fluid on base I guess. It amounts to a drop forming on the head of 1 screw and takes awhile to get there.
I tried to tighthen screw but it appears tight, might have to get different screw driver to see, just don't want to round off screw head ot crack housing. Could i put a small dab of silicone around the area without hurting anything?
Also when I fill up my resvoir to prime? bleed any air out or?? Thanks

 

[b-man]

Re: changing lower gear lube on force 125hp

Thanks for the help Frank,
On the reply I posted there was another question regarding a trim motor, I not sure if you seen it, if you can look at it and give me your take on this also? Thanks for your time

 

[Frank Acampora]

Re: changing lower gear lube on force 125hp

There is a thin O Ring sealing the pump body to the reservoir. That is amost likely what is leaking. Send a PM to RRitt and see if he has one for you. Check the reservoir and pump body for nicks.

The four screws go into plastic and only need to keep the pump against the reservoir--the O ring does the sealing. No matter how tight you try to screw them, the seal will not get better if the ring is nicked. And yes, you run the risk of cracking the reservoir if they are too tight, but more likely you will strip the holes.

 

[b-man]

Re: changing lower gear lube on force 125hp

Thanks for your help and time,

 

[ranger6202]

Re: changing lower gear lube on force 125hp

What happens when you "accidentally" remove the shift fork screw? And how can you tell if anything is wrong if you did?

 

[Beto1980]

Re: changing lower gear lube on force 125hp

What happens when you "accidentally" remove the shift fork screw? And how can you tell if anything is wrong if you did?

It’s really difficulty to put back.

 

[racerone]

That was 14 years ago.-----Issue must be sorted out by now !!