67 9.5 rude leaking behind prop?

[Fisherdave67]

Just bought this motor and I was told to add gear oil twice a year as there was a leak behind the prop, more often if I ran the motor a lot. I ran it yesterday; I notice a milky light brown liquid coming from behind the prop. Do I need a Lower unit seal kit? How do I id the kit I need? Any recommendations on where I can purchase the kit? Is this a difficult project?

 

[ezeke]

Re: 67 9.5 rude leaking behind prop?

Drain a little oil from the gearcase and see if it is milky looking.

The lower unit seal kits from iboats work fine. http://www.iboats.com/Sierra_18_268...6786070--**********.560449424--view_id.174398

Put 12 PSI pressure on the empty gearcase using the vent plug and a pump with a gauge. If it holds for 45 minutes, it is not the seals.

 

[Mas]

Re: 67 9.5 rude leaking behind prop?

I would do a reseal of the LU. It sounds like the prop seal is leaking.

Difficult project???...it's not with the OEM manual.

MAS

 

[Fisherdave67]

Re: 67 9.5 rude leaking behind prop?

Can you give me a rough estimate at the cost difference between doing myself and having a marina or boat motor mechanic replace the seals in the lower unit.
Don't get me wrong I've already purchased and I'm waiting for the owners manual and parts catalog to arrive so I can start getting my hands dirty. When my wife asks why I'm tackling the project vs having it done by someone else I'd like to give her a cost comparison and put the issue to rest.
Also, while I have your ear, my prop has some play in it, about a quarter inch up and down the shaft, is this normal?
Thanks everyone for all your help and support!

 

[ezeke]

Re: 67 9.5 rude leaking behind prop?

You should have no horizontal play in the propeller on the shaft, it could ruin the hub of the prop as well as causing the drive pin to weaken unnecessarily.

If you have the correct drive pin behind the propeller, and the nose cone will not tighten enough to hold the propeller firmly, use nylon washers available from plumbing area in larger hardware stores for spacers.

 

[lindy46]

Re: 67 9.5 rude leaking behind prop?

Can you give me a rough estimate at the cost difference between doing myself and having a marina or boat motor mechanic replace the seals in the lower unit.
Don't get me wrong I've already purchased and I'm waiting for the owners manual and parts catalog to arrive so I can start getting my hands dirty. When my wife asks why I'm tackling the project vs having it done by someone else I'd like to give her a cost comparison and put the issue to rest.
Also, while I have your ear, my prop has some play in it, about a quarter inch up and down the shaft, is this normal?
Thanks everyone for all your help and support!

Seal kit is $20-25. Tools to do the job right can get expensive. Pressure tester: $30-35; Seal puller: $15-20. If the shift rod seal is leaking, you need a special tool to remove the old one; another $15-20. I had a quote a few years ago to re-seal my 18hp lower unit and it was $140 at the marina. I went ahead and bought the tools and learned a lot! Probably a little cheaper to do it yourself, and then you have all the tools to help your friends fix their motors! If you're not mechanically inclined and don't especially like to get your hands dirty, let the marina do it.

 

[iwombat]

Re: 67 9.5 rude leaking behind prop?

If memory serves the 9.5 split lower doesn't require any special tools to replace the prop seals. It's a fairly easy job with the OEM manual.

 

[billy4hp]

Re: 67 9.5 rude leaking behind prop?

Just bought this motor and I was told to add gear oil twice a year as there was a leak behind the prop, more often if I ran the motor a lot. I ran it yesterday; I notice a milky light brown liquid coming from behind the prop. Do I need a Lower unit seal kit? How do I id the kit I need? Any recommendations on where I can purchase the kit? Is this a difficult project?

Before you jump the gun on replacing the seals, check the oil level and make sure it isn't either milky or low on fluid... If the level is okay and not milky, the problem may not be a seal leakage issue, but exhaust spooge...

Reason I say this is the 9.5 doesn't dump the exhaust through the prop but discharges above the prop. After running my 1972 9.5, I always get exhaust oil spooge that runs out the discharge and then it runs down between the case and the prop. I was sure I had a oil seal leak like you do, but after seeing where this oil trail came from I decided to pull my prop off, wipe everything down and let it sit a day or so... Sure enough the oil was exhaust oil discharge and not lower unit seal leakage... It's not a large amount of oil but it was enough that I was concerned for awhile...

It's worth a shot and basically a free check other than the cost of the cotter key to hold the nose cone on....

Good luck,

Billy

 

[LongLine]

Re: 67 9.5 rude leaking behind prop?

If you determine it's a prop shaft seal...carefully drill two very small holes 180 deg apart thru the metal part of the seal. Screw in two very small screws part way. Take two pieces of metal about 1/4-3/8" wide, bend ends in a vice roughly 90 deg. File a small groove in the bent end. (ie make a miniture crow bar) Use the crow bar to pry under the heads of both screws. Seal will come right out.

Tom B.
(LongLine)

 

[Sailormannj]

Re: 67 9.5 rude leaking behind prop?

Where can you get the seal puller tools? I am in the middle of doing this on a 1961 10 hp Johnson and now need to pull the seals from the prop hub, water pump plate and the shift rod seal.

Are there any other workarouds to the tools?

 

[lindy46]

Re: 67 9.5 rude leaking behind prop?

Where can you get the seal puller tools? I am in the middle of doing this on a 1961 10 hp Johnson and now need to pull the seals from the prop hub, water pump plate and the shift rod seal.

Are there any other workarouds to the tools?

The prop seal bushing may have two holes drilled in it 180 degrees apart. I just use a small punch to push the seal out from the back side of the bushing, alternating taps through both holes. If no holes, just use the punch and tap on the back side at an angle moving around the seal until it pops out. You'll destroy the old seal - just be careful not to nick the bushing. The driveshaft seal requires a standard seal puller which can be purchased at an auto parts store or on ebay for about $12-15. The shift rod seal is the tricky one - requires a hardened rod about the same diameter as the shift rod at the end. It then has a collar and the rest of the shaft is fatter than the end. I bought one on ebay for $12. You could probably fabricate one by getting a fat rod and grinding the end down to the smaller diameter so it will fit though the brass bushing which contain the O-ring. Make sure it's long enough as it has to reach down into a pretty inaccessible spot in the lower unit.

 

[Mandrake35]

Re: 67 9.5 rude leaking behind prop?

There are umpteen different ways to get the seals out.....if you have the lower end apart you can bang out the prop seal from the other side. Be careful to order the correct year when getting the seals. I have a 1965, and the seals are slightly smaller than a 1968. This is one of the litttle changes to this motor to keep in mind. Once you get the right size seal things go a lot easier hahaha.


ps almost forgot.....for the shift rod linkage seal...I just flipped a normal spade wood drill bit upside down. The hexagon that fits into the chuck of your drill fits through the brass bushing, but the round shank of the bit doesn't tap tap tap, and its out.

 

[Sailormannj]

Re: 67 9.5 rude leaking behind prop?

Thanks for the replies.

Mandrake,

on the wood drill, did you go from the bottom side of the bushing, the inside of the gear case and push it out that way, from the bottom?

 

[Mandrake35]

Re: 67 9.5 rude leaking behind prop?

Sailorman..... Yes, I had the whole thing dissassembled, but for the life of me couldn't figure out how to get that bushing out. One of the threads on here led me to trying the "bit technique" It worked great. Just flip the gearcase/lower unit upside down.... I had mine clamped to the workbench, I flipped I think a 1/2" or 5/8" spade bit upside down, then fit a deep socket over the pointy end, and tapped out the bushing. It required way less force than I thought it would. Hope this helps......just let me know if I need to clarify it at all.

 

[Sailormannj]

Re: 67 9.5 rude leaking behind prop?

Mandrake, thanks for the clarification. I will give it a try tomorrow. I have the unit totally apart and on the bench. After that then I will tackle the other seals.

 

[Fisherdave67]

Re: 67 9.5 rude leaking behind prop?

Thanks everyone, you've all been a great help, today I took off the prop and it is definitely the prop shaft seal (thanks billy, my local rude dealer suggested the same thing). I think I'll fill the unit and run it a couple times to see just how bad the leak is. Thanks longline for the seal removal tool suggestion, it sounds like that may the way I go when it's time to fix that seal.

 

[Mandrake35]

Re: 67 9.5 rude leaking behind prop?

That seal is vulnerable to fishing line.....which can chew it up in a hurry. Mine barely had any rubber skirt left on it. Good luck

 

[Fisherdave67]

Re: 67 9.5 rude leaking behind prop?

thanks