1957 evinrude fleetwin lower unit rebuilding question

My lower unit on my 1957 evinrude fleetwin is getting water in it . When I opened the lower drain plug after you times out on the water . It had about one tablespoon full of water in it . you can tell the water came out fast than the oil came out of the lower unit .

How hard is it to change the seals in the lower unit on a 1957 evinrude fleetwin 7.5 . I rebuilt the powerhead last spring and its fine . But the lower unit has some water in it . I see that the kit is like 25.00 and the impeller kit is like 32.00 dollars . I wouldn't want to skip a step in rebuilding the lower unit . What would it involve me disassembling on it . Would you see a worn out shaft for the prop and the drive shaft . thats the only places it could leak to me , maybe more places too Im over looking on this . I wont do this untill I have some money for the parts needed . I only want to replace the parts that need replacing too . why wast money on stuff I dont need in the first place . So this job wont take place untill its near spring, like march or so . That gives me time to order the parts from the internet .

Re: 1957 evinrude fleetwin lower unit rebuilding question

I can tell you from experiance, if you are taking lower unit apart replace all the seals. if you have the skill to do the power head, then you should be able to get through a lower unit. A good tip to use is as you take it apart take lots of digital photos as you go, when you go to reassemble use them for referance. water can get into any of the seals

Re: 1957 evinrude fleetwin lower unit rebuilding question

You should have the l/u pressure tested before taking it apart. Takes the guess work out of it where it's leaking. May save you some $$$$.

Re: 1957 evinrude fleetwin lower unit rebuilding question

Can I test or should I test the lower unit with compressed air . I heard of a guy making a bicycle style tester .I need air compressed in it to test for leaks right . Also how much pressure will I need to maintain in the lower unit . I bet I can rig a tester of some sort . I seen a video on you tube of a guy doing this to test for leaks . This way I can see where its comming from . But its easy to replace the seal next to the prop . I may just start with that one first . I bet its from fishing line over the last summer . I did get line wraped around the prop last summer . Like I said I got maybe close to a tablespoon of water out of the lower unit after i went fishing . But thats after two tripps out on the water . I hope no metal parts are worn out around the shaft for the prop or the drive shaft where the water pump . If I have to take the whole lower unit apart , then I mite as well change the water pump too . But Im betting the last person that owned it before me did that .

Re: 1957 evinrude fleetwin lower unit rebuilding question

The first thing to test is the drain and vent screw gaskets, they are the cheapest and easiest fix. They should be changed every time you do the oil, they are a 1 time use.

While pressure testing the gearcase is a good way of determining which seal is at fault, I never do it. If I am going to spend the time, especially on a Fleetwin like yours where you have to pull the powerhead to drop the gearcase, to open the gearcase up, all the seals are getting changed. The kit is the best way to go and will cover everything you need. You will also need a tube of 3M847 as a sealant part number 776964. I then pressure test it when I am done to ensure the gearcase is holding pressure. 6 to 8 pds then again at about 12 lbs. Submerge in water and spin drive shaft, prop shaft etc...

The items that will be changed are as follows:

Bearing housing seal 300599 located beneath water pump
Shift rod seal (actually an o ring) 301877
Prop shaft seal 303345
Prop shaft head o ring 303360
Spaghetti seal 303328
Pivot pin washer 304083

Then of course while the gearcase is down change the impeller. Should be done every few years anyways. I do it on any new motor to me. Part number 277181

Now a very important aspect of protecting your powerhead on the Fleetwin is the carbon seal assembly. Inspect this assembly and replace as needed. If overlooked, water will destroy your rebuilt motor.

Re: 1957 evinrude fleetwin lower unit rebuilding question

@ High trim
I replaced the drain vent screws gaskets last summer . No luck on that one . One of my seals are leaking , I dont think its too bad but any amount of water in the lower unit is no good . Im going to check with a vacuum tester . I can get pressure out of it . I think that will be plenty of pressure for testing purpose's . Im hoping its only the seal around the prop if not then Im going to need to take off the powerhead and disasemble the lower unit . But right now its too cold out to do that . My garage is not heated and Im broke now anyway . But when spring is here I want it rebuilt before that so I can take it out fishing . Im also going to have to buy a new switch for my minn kota electric motor . I fried that last time I was on the water . thats a minnkota 35 and I can use the newer style switch too . Just to let you know that . Its all the same .

Re: 1957 evinrude fleetwin lower unit rebuilding question

To replace any of the seals (other than the vent and drain bolt washers) requires dropping the lower unit and removing the skeg. That's why it makes sense to replace them all while you've got it apart. And don't forget the impeller.

Re: 1957 evinrude fleetwin lower unit rebuilding question

Ive actually changed the prop shaft seal before without dropping the gearcase. Just inverted the whole motor and removed the skeg. It can be done. I was up north and it was for a friend, fishing line shredded the seal pretty bad and didnt want to spend the time on a Saturday to redo the whole thing. Only done it once though.

Regardless, as stated, I wouldnt reccomend doing that. If you are going to do it, get the kit and reseal it all and be done with it.

Re: 1957 evinrude fleetwin lower unit rebuilding question

I also just changed out a propshaft seal ('65ish 40hp Evinrude). Guy had a seal kit installed 2 yrs before, and had fireline get behind his prop. He was sure it was just the propshaft seal, so I inverted motor, removed skeg, and replaced just prop seal. Except for that type of scenario, just change 'em all out and be done with it.

Good luck!

Re: 1957 evinrude fleetwin lower unit rebuilding question

your a fool if you don't change all the seals when you are in there. the most likely culprit is the shift shaft seal. You will need to make a tool to drive out the bushing but not hard to do.

Re: 1957 evinrude fleetwin lower unit rebuilding question

X2 on the shift rod seal.

Re: 1957 evinrude fleetwin lower unit rebuilding question

Well You guys are right . I sould change them all out and get right the first time . The kit for the seals are 25.00 bucks But Im not sure if you get the shift shaft seal too . But water pump kit is like 35.00 too . from www.vintageoutboard.com

Re: 1957 evinrude fleetwin lower unit rebuilding question

Just go to your local dealer and get the impeller, will be about 25 bucks. Shift rod seal is a couple bucks at the dealer as well.

Re: 1957 evinrude fleetwin lower unit rebuilding question

Shift rod seal is an O-ring which should be in the kit. As HighTrim says, they're only a couple bucks at any Johnnyrude dealer if it's not in the kit. I've had two of the same lower units with water intrusion in the last couple months, and in both cases it was that little shift rod O-ring which was leaking. You do need a special tool/punch to get the bushing out which holds the O-ring in place.

Re: 1957 evinrude fleetwin lower unit rebuilding question

Here is where to get the aforementioned tool

Frank's Tools

Re: 1957 evinrude fleetwin lower unit rebuilding question

This may help too.

http://forums.iboats.com/johnson-evinrude-outboards/fastwin-lower-unit-seal-faq-277190.html

Re: 1957 evinrude fleetwin lower unit rebuilding question

I just bought a 1957 Evinrude fastwin 18 hp, and brought it home to find oil leaking down the prop. I understand that this means I need a prop seal. I took off the cotter pin, prop nut and prop. I looked inside and cannot find the prop seal. Shouldn't it be right there? Or do I need to go deeper?

Re: 1957 evinrude fleetwin lower unit rebuilding question

On the subject of pressure testing the gear case has anyone ever tried using/converting one of those manual hand pumps/blood pressure meters as a referrence.

Should be easy to pump it up to 150...whatever pounds that represents ... any leaks would show up quickly with the reading dropping

Father passed away few montha ago and I have his blood pressure pump waiting to be used....

Re: 1957 evinrude fleetwin lower unit rebuilding question

Hi jgarard. Welcome to iboats. The prop shaft seal is what the prop shaft itself passes through. It can be hard to differentiate from the bearing it's housed in, but it's sort of like a metal donut with a rubber inner seal. You'll need to get a seal puller and leverage it out. Be careful you don't damage the soft aluminum housing. Just got slow and take your time. You'll need to open the entire lower unit to access the part properly and then reseal it with an LU kit and some 3M 847 gasket maker. Start a new thread as well so we can keep all of the issues organized.

Re: 1957 evinrude fleetwin lower unit rebuilding question

Crosbyman any type of pump with a gauge on it calibrated low enough to accurately measure say 5 to 15 psi will work.

I used to use an old bicycle tire pump with a gauge on it. I cut off the end, then took an old gear oil pump, cut the end off that and put it on the bike pump. Used that system for a while to pressure test until I got a better pump. The old bicycle pump worked fine though.