FT9.9GE Oil seepage from shift rod seal

[cleddau1]

Second engine on my 32 foot catamaran; lower unit was upside down while I touched up paintwork; noticed oil seeping from the seal where the shift rod enters the drive shaft housing. Also have some corrosion of the housing itself where the water pump sits. I would like to replace the housing and the seals as if oil can get out water can get in.
Question is do I need to remove the drive shaft to do this? This would mean removing propeller shaft and it's housing and somehow get at the clip at the bottom of the drive shaft etc etc.
Had already changed the gearbox oil and no obvious emulsification.
Any advice would be much appreciated.

[99yam40]

I would pressure test and then decide what all to take apart.
Might want to give all the plate data on the motor model and serial so Boscoe can give us a model # that we could compare parts on.
My guess right now is the housing below water pump has the seal in it, so if you remove the housing carefully you should be able to replace housing and seal without removing the drive shaft.
But then I have not worked on a t9.9 before

[panasonic]

Cleddau,

I am confused to which housing you are talking about replacing? You can change all the seals in the L/U on that engine without removing the drive shaft.

If there is no water in the lower unit oil I would leave alone. Replace the shift shaft seal, which is simple and pressure test the LU.

Please take a few pictures for us and post your model again as its been awhile since we heard from you....

[cleddau1]

http://www.boats.net/parts/search/Ya...201/parts.html

The oil seal that is leaking is No 24 on this diagram, the housing that is corroded is No 20. The housing holds a bearing for the drive shaft so it would be surprising if the housing simply pulled off. This is a 2009 engine Europe spec and a different engine from the one I did the head refurbishment on.

[cleddau1]

Had another look at the service manual Page 8-45 says " Be sure to remove the drive shaft before trying to remove the drive shaft housing" so better set aside a couple of days to do this. However will get a quote from local Yamaha repair shop first.....

[rodbolt17]

depends on how corroded this blowboat motor is. most blowboat motors are the most comepleatly neglected hunks of AL that I see.
however it typically takes me about 4 hours to disassemble,clean and reassemble that unit.
I did make a tool that threads on my slide hammer to adapt the slide hammer to the prop shaft so I can pull the carrier and shaft together.
to unthread the drive shaft nut lock the shaft in a vice.
the rest is fairly simple.

[cleddau1]

Diolch yn fawr, Rodbolt, the housing corrosion is just some pitting, because, unlike all other sailboat owners, I do take the water pump apart every autumn. However my boat is on a swinging mooring in an estuary so flushing with fresh water after each use is not practical. There is always a salty paste sitting on the housing, that does not happen on my 1998 FT9.9 that has a different design. It is only because I want to change the seal that I thought to change the housing. I note the housing is £40 on boatsnet but costs £87 at my local dealer. If the job takes you 4 hours my guess of 2 days for me is probably about right, many thanks.

[cleddau1]

Completely snowed in the last few days so thought I would have a go at this. All went well as far as removing the 2 bolts holding the propshaft bearing housing. The bearing housing was completely stuck. My bearing puller hooks were too big so I used a couple of threaded "J" bolts and managed to hook on my slide hammers Tried to think of a way to adequately cool the housing while warming up the casing in the face of high thermal conductivity of aluminium. Tried warming the casing with hot water and also gentle torch and cooling the hosing with ice/plumbers freeze but no joy. Thought maybe it needed a bigger thermal mass in the bearing housing so put some thin oil in the freezer overnight, poured this into the housing and warmed the casing whereupon the housing promptly fell out. Now for the difficult part.....

[panasonic]

Completely snowed in the last few days so thought I would have a go at this. All went well as far as removing the 2 bolts holding the propshaft bearing housing. The bearing housing was completely stuck. My bearing puller hooks were too big so I used a couple of threaded "J" bolts and managed to hook on my slide hammers Tried to think of a way to adequately cool the housing while warming up the casing in the face of high thermal conductivity of aluminium. Tried warming the casing with hot water and also gentle torch and cooling the hosing with ice/plumbers freeze but no joy. Thought maybe it needed a bigger thermal mass in the bearing housing so put some thin oil in the freezer overnight, poured this into the housing and warmed the casing whereupon the housing promptly fell out. Now for the difficult part.....

Filling the case with cold oil is a great idea and I am glad it worked. Never would have thought of that myself.!!

[pstephens46]

I am kind of confused about what was filled with oil and what was heated. Can you elaborate? Filled through the lower unit fill hole? And heated the outside of lower unit casing?

If this works, great info.

[cleddau1]

The oil at approx -20 Centigrade was poured into the LU around the propeller shaft with the latter pointing skywards, the exhaust/cooling water channel in the leg I stuffed with rats and also tilted the leg up slightly. Although the casing in this area would also be cooled I figured the combined thermal mass of propshaft bearing housing, oil and part of the propshaft would be so much more than that of the thin casing there that I could warm the casing while the housing stayed cold. The puller was already set up and I let the oil sit for a few minutes before warming the casing gently.
I used some synthetic 5-30W oil and was surprised to find that after a night in the freezer it was like treacle. Frugality suggested using old sump oil but messy and the 5-30 was left over from an oil change and handy......

[cleddau1]

All dismantled now and cleaned and parts have arrived so ready to assemble. The manual says use water resistant grease (Yamaha A) on the inner O ring on the propshaft bearing housing and corrosion resistant grease (Yamaha D) on the outer. Yamaha D is not available what can I use as an alternative? Also the adjacent metal surfaces are bare so it is tempting to use some non setting gasket sealant on these. Is this wise?
There is no mention of any sealant for the gasket between the drive shaft bearing housing and the case, is this assembled dry?

[panasonic]

I take it you have Yamaha type A grease or are going to get some. That will be fine to lube the orings and the prop shaft housing. Always a good idea to put a thin smear of grease on the bare surfaces that you speak of.
I would not use any gasket type sealant on that assy.

[cleddau1]

Thanks Panasonic: have assembled driveshaft and shift rod; what is the tolerance for vertical movement of the driveshaft? Cannot find it in the manual.

[panasonic]

LU.jpeg

Thanks Panasonic: have assembled driveshaft and shift rod; what is the tolerance for vertical movement of the driveshaft? Cannot find it in the manual.

Ok a few questions:

Is this the manual you used? LIT-18616-03-03 this is the manual I found for your engine 2009 FT9.9GE

Did you only replace seals and O-rings in the LU?

Are you sure all original shims went back in their proper positions? (driveshaft pinion shim)

If yes to all, there is no need to be concerned with the vertical movement of the driveshaft it should be back to proper height in the case as set from the factory. As long as it turns smoothly, shifts smoothly, and you have some backlash