gear oil change

[vincedv]

hey all i have a 84 150hp v6 i need to change the lower unit oil. i have what looks like 3 screws on the unit . i know the one on the bottom is the drain screw. which is the vent? i havea screw near the gills( what i call them in the middle of the lower unit) and one at the very top where the lower unit bolts to the shaft. i drained the oil and refilled it nothing came out the very top screw only the one near the gills in the middle. i put in a qt of oil. how much dose it take. sorry about all this its all new to me.
thanks

 

[cr2k]

Re: gear oil change

There is a screw on the bottom of the bullet near the front. This is the drain/fill screw. There is one that should look just like it (large flat slot) on the side just below where the lower bolts to the upper. This is the vent hole.

Pull bottom screw first no to drip flow, then pull top screw and oil will flow. When done draining fill from the bottom (you can get a screw in fitting at just about any marine store) fill until the oil comes out the top. Replace gasket on screw and replace screw and tighten. Now you can remove the bottom filler and there should be very little escape new gasket and replace and tighten the bottom screw. You are done.

 

[metriccrescentwrench]

Re: gear oil change

Also, DO NOT, repeat DO NOT loosen that screw in the middle. It's the pinion bearing setscrew, and somebody will be taking the lower unit apart to get it put back in properly.

 

[cr2k]

Re: gear oil change

Never take out a screw that is Small or Phillips head. Grear oil screws are large and slot.

 

[vincedv]

Re: gear oil change

what happens if you loosen that middle screw?

 

[cr2k]

Re: gear oil change

If you loosen it but didn't pull it just tighten it. otherwise parts inside will not be where they need to be and can cause catastrophic damage.

 

[vincedv]

Re: gear oil change

i think i'm f'D . i had it out. anyway to tell if anything got messed up?

 

[tx1961whaler]

Re: gear oil change

i think i'm f'D . i had it out. anyway to tell if anything got messed up?

It won't shift if it's messed up. IF you got lucky and nothing moved before you put the screw back in, then it's OK. If it moved and it's out of line, then you can realign the cradle with a tiny screwdriver, peering down the hole while lying on your back with a flashlight. Or take the lower unit off . Or disassemble it.

 

[wilde1j]

Re: gear oil change

It's much easier to get the Philips screw (it's the shift cradle pivot) back in place with the lower unit off and laying on it's side. If you leave the LU on, gravity will be your enemy. The hole needs to line up with the hole in the cradle for it to work. Not in means no shifting. In any case, you will learn patience is a virtue AND don't remove stuff you don't know about, especially Philips screws.

 

[boobie]

Re: gear oil change

I believe he said he had a 150 hp mtr. On that mtr all the philips screw does is hold the pinion gear bearing in place. There's no cradles attached to it. All he has to do is make sure its sealed and put it back in before he runs it.

 

[vincedv]

Re: gear oil change

yes boobie i have a 1984 150 hp vro v6. the screw was not a Philips screws it was a flat head with a 6 point head.

 

[seahorse5]

Re: gear oil change

i think i'm f'D . i had it out. anyway to tell if anything got messed up?

On your 150, the Phillips screw is the retainer for the pinion bearing. Just make sure the oring seal is in good shape and reinstall it. It is NOT the pivot for the shift cradle, that is only used in the small and medium sized engines.

 

[wilde1j]

Re: gear oil change

My bad, sorry.

 

[vincedv]

Re: gear oil change

boobie and seahorse you guys are correct. thanks to all for your help