Johnson 1993 48- where are shims, leaks

ba_50

Chief Petty Officer
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Apr 4, 2001
Messages
635
Hi,

I would like to know where to look for the shims in the lower unit so I can get them back right.

There is oil coming out of the prop are are but the rear seals appear dry. Could it be coming out somewhere else? Thanks.
 

ezeke

Supreme Mariner
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Sep 19, 2003
Messages
12,532
Re: Johnson 1993 48- where are shims, leaks

The oil that you see dripping from the prop is usually just unburned oil from the engine - that's normal.
 

ba_50

Chief Petty Officer
Joined
Apr 4, 2001
Messages
635
Re: Johnson 1993 48- where are shims, leaks

After about 2 hours of operating on new gear oil, there is water in the gearcase. I can see the gray sludge dripping out of the prop area. It's not unburned oil. I forgot I drained the lil so that is probably why the seal look dry.
 

ezeke

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Re: Johnson 1993 48- where are shims, leaks

Oil and water in new gearcase oil appears as a creamy light color, not usually gray but always creamy.

If you drain the oil, it will be easy to spot because water is heavier than oil and the mix will be first out of the drain hole. Be sure to replace the seals on the fill and vent screws with new ones, that is where the most leaks occur.

The easiest way to find gearcase leaks is to do a pressure test. You will need to remove the gearcase and the water pump first, so that you can observe the area of the seals on the driveshaft and shift rod.

10 to 12 psi and some dishwasher soap is adequate to spot most leaks. if you don't see them, immerse the unit and look for bubbles.
 

ba_50

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Messages
635
Re: Johnson 1993 48- where are shims, leaks

Ezeke

It is creamy yellow in color with gray on top. Do you know where the shims would be if there were any?

Can a pressure tester be made? Thanks.
 

ezeke

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Re: Johnson 1993 48- where are shims, leaks

LubriMatic makes a "LubeTube" that has a fitting which enters the fill/drain hole and can be used with any pump that has a gauge, i.e. bike pump, tire pump, etc.

http://www.iboats.com/mall/?keywords=lube tube&cart_id=673694272&session_id=832807013&view_id=192464

The Mercruiser "LubeTube” that they sell here at Iboats fits, but you can find them at boating stores and sometimes at Walmart.

Anyway, the idea is that you can use the fitting and your bike pump to pressurize the empty gearcase. I like for mine to hold pressure for 15 minutes.

The "LubeTube" is handy for filling with the smaller gear lube containers, so they are good to have around anyway.
http://www.iboats.com/mall/image/vendor/7/big/47669_0.jpg

The shims are in the inner part of the Gearcase and you can replace all of the relevant seals without dealing with them. If you do deal with them you need a special tool.
 

yamamarinetech40

Petty Officer 1st Class
Joined
Dec 17, 2006
Messages
328
Re: Johnson 1993 48- where are shims, leaks

If you don't know what you are doing you don't want to mess with the shims...why would you want to? Something else wrong? Besides seals?
 

ba_50

Chief Petty Officer
Joined
Apr 4, 2001
Messages
635
Re: Johnson 1993 48- where are shims, leaks

It's just that a manual said to make sure the shims got put bak in the right place, whcih makes me think they might be laying along side loose when it is pulled out.

I tried to use a bicycle pump on my luber but couldn't get the plastic tubes to seal up. Will find something different. This one doesn't have a gauge anyhow.
 

DHPMARINE

Captain
Joined
Dec 16, 2003
Messages
3,688
Re: Johnson 1993 48- where are shims, leaks

If the unit is taking on water,you need to reseal it.All the seals and orings are 14 years old,so do them all and at least a water pump impeller.

Doesn't your manual show where the shims are ? I think the only place you'll have a problem is the drive shaft seal housing.There are shims under it.Just don't lose any.I don't think you'll disturb any other shims.

DHP

if your manual doesn't show shim location,get the real manual.
 

ezeke

Supreme Mariner
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Sep 19, 2003
Messages
12,532
Re: Johnson 1993 48- where are shims, leaks

Regarding the pressure test: "the idea is that you can use the fitting"

The LubeTube fitting is metal. Use a hose clamp.
 
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