Oil leak lower unit - shift shaft - Mariner 40 hp

[steffo5]

Recently I discovered a leak in my lower unit. It appears it comes from the shift shaft as you can see in the image within the red circle http://imageshack.us/a/img4/5572/njqv.jpg When I push air through the oil fill hole the shift link goes a little bit upwards and air/oil is coming out. That isn't normal right?

I already managed to losen part 8 and 11 from this exploded view Mercury, Mercruiser, Force, etc. - GEARHOUSING ASSEMBLY - 40 H.P. but I can't seem to find a O-ring/oil seal. Is part 74 to 77 also parts of the shift shaft? I can't figure it out how to fix this problem. Is there maybe a youtube video about this problem?

And another little question: which gasket(o-rings,gaskets,seals) kit I should buy for a Mariner 40hp (40 EO - 6E9 S 150087) for my lower unit?

 

[Yesterday]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

Recently I discovered a leak in my lower unit. It appears it comes from the shift shaft as you can see in the image within the red circle http://imageshack.us/a/img4/5572/njqv.jpg When I push air through the oil fill hole the shift link goes a little bit upwards and air/oil is coming out. That isn't normal right?

I already managed to losen part 8 and 11 from this exploded view Mercury, Mercruiser, Force, etc. - GEARHOUSING ASSEMBLY - 40 H.P. but I can't seem to find a O-ring. Is part 74 to 77 also parts of the shift shaft? I can't figure it out how to fix this problem. Is there maybe a youtube video about this problem?

And another little question: which gasket(o-rings,gaskets,seals) kit I should buy for a Mariner 40hp (40 EO - 6E9 S 150087) for my lower unit?

I don't know this LU specifically but part 74-77 look like your water tube which carries water from the pump up to the block.
Typically where the shift shaft enters the LU there's a seal, likely seen in another exploded part of the LU diagram.

At the very bottom of the link you posted, was a gasket kit listed for that engine.
27-94533M | GASKET SET | Mercury | Crowley Marine
A couple more clicks got me here:
Mercury Quicksilver Gasket Set Qpd=no Nla @ MarineEngine.com
Does that look like the right set? If so it says no Longer Available, but at least the part number should help you find one.

This link may also be helpful for you:
http://eastmarine.ru/incp/katalog/GLM/mm.pdf

 

[steffo5]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

Thanks for you're information. But I still can't figure it out. I can't find any O-ring/oil seal. How is it possible that the shift linkage is going upwards when I bring the lower unit on pressure and air is streaming through the shift tube? Should part 8 or 11 be some sort of oil seal?

 

[Yesterday]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

Thanks for you're information. But I still can't figure it out. I can't find any O-ring/oil seal. How is it possible that the shift linkage is going upwards when I bring the lower unit on pressure and air is streaming through the shift tube? Should part 8 or 11 be some sort of oil seal?

Are you able to post any pictures? They usually are very helpful for others to see what's going on.

 

[steffo5]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

Are you able to post any pictures? They usually are very helpful for others to see what's going on.

I have made a video of my problem iboats leak lower unit - YouTube The gear link is going upwards when I push air through it. I now know that it pops from neutral into gear so that's no problem , but the leak is huge, but can't see what's wrong with it.


Hereby the images:

the parts that I removed. They were seated around the gear link. Could that rubber thing be an oil seal?
http://imageshack.us/a/img829/2161/drk9.jpg


Gear link in the right (thread)
http://imageshack.us/a/img14/1646/fugw.jpg

The hole where the gear link is in. It looks like some sort of metal tube and it's goes pretty deep. I can't figure out how to losen this up, or where a oil seal needs to be placed.
http://imageshack.us/a/img547/8274/8xbr.jpg

Hope things make more sense now and that someone is able to help me

 

[Yesterday]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

Hereby the images:

the parts that I removed. They were seated around the gear link. Could that rubber thing be an oil seal?
http://imageshack.us/a/img829/2161/drk9.jpg

It sure looks like that's exactly what it is. An oil seal/boot combo

Gear link in the right (thread)
http://imageshack.us/a/img14/1646/fugw.jpg

Yes that's definitely the shifter rod.

The hole where the gear link is in. It looks like some sort of metal tube and it's goes pretty deep. I can't figure out how to losen this up, or where a oil seal needs to be placed.
http://imageshack.us/a/img547/8274/8xbr.jpg

The seal/boot affair when placed inside, seems smaller than the channel in which it seats? It looks like it's primarily an O-ring based setup and that possibly replacing that O-ring should be all that's necessary. I'd also look for one inside of it, or is it a very snug fit onto the shift shaft? The channel leads into the lower unit itself along side of the drive shaft, essentially. It (typically) attaches to a shifting cam which then controls the transmission. You'll not "loosen" the channel unless it has some sort of tube/liner inside it.

Hope things make more sense now and that someone is able to help me

Again apologies for my lacking of familiarity with your specific motor. I too had hoped someone who knew it specifically, would chime in. In the interim, I'm trying.

 

[steffo5]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

I think the tube (nr 11 on diagram) is indeed the oil seal. The previous owner placed number 11 in the tube of number 8 (makes no sense though). And I think number 11 needs to be beneath number 8. When I place it in that order it seals pretty good. Mercury, Mercruiser, Force, etc. - GEARHOUSING ASSEMBLY - 40 H.P. so first nr 11 into the shaft and then nr 8 to keep the seal in place

 

[Yesterday]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

I think the tube (nr 11 on diagram) is indeed the oil seal. The previous owner placed number 11 in the tube of number 8 (makes no sense though). And I think number 11 needs to be beneath number 8. When I place it in that order it seals pretty good. Mercury, Mercruiser, Force, etc. - GEARHOUSING ASSEMBLY - 40 H.P. so first nr 11 into the shaft and then nr 8 to keep the seal in place

yes, I'm thinking you're on the right track. #8 is a cam/shaft likely for the shifter and looks like it's a connecting piece to what's above. If he slid the seal up onto that cam, and didn't seat it into the lower unit, it would in effect be doing nothing, which probably explains why you're here and doing this again.

It's a crappy deal but it's nice to know what's wrong in the first place!

 

[steffo5]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

Got it fixed, but now I have the next problen. How do I need to replace my lower unit?

I already placed it, but I have forward, neutral, but backwards won't work 100%. I noticed that the shiftlever doesn't go far enough when I put the throttlelever in backwards. I already adjust the cables but I can't find a sweet spot so all gears work. So I think I misplaced the lowerunit or need to adjust the linkshaft.

 

[steffo5]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

Can anyone advice me how to mount my lower unit for this type of engine? Gearshaft in neutral and throttle lever also in neutral?

 

[minuteman62-64]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

I have an '82 30 HP, which appears to be somewhat similar. On mine, it works best if I disconnect the shift cable and just work with the shifter handle on the side of the motor.

Again, on mine: with the LU down, use the lower shift shaft to put the gear box in neutral (test by rotating the driveshaft clockwise - you may have to rotate the driveshaft to allow the shift shaft to function). Put the shifter handle also in neutral. Then hook up the LU and join the shift shaft.

If you have to shift gears to bring the shift shaft to where you can join it, make sure the shifter handle and gear box are in sync (both in neutral/both in forward/both in reverse).

Hope this helps.

 

[minuteman62-64]

Re: Oil leak lower unit - shift shaft - Mariner 40 hp

On closer look, you don't have a lower shift shaft sticking up from the LU as is the case with mine. Not sure how it would be done, but there's got to be a way to move the shift cam through the 3 positions (F, N, R) with the LU dropped. Maybe a screw driver?