Roadblock with Gearcase head/propeller shaft seal replacement.

[antnida]

This is for a '64 Evinrude 18hp 18402D. The propeller shaft called for part number 313284, Sierra lower seal kit come with part number 311787 equivalent. There should not be a fitment issue with either of this part. One is ID .625, OD 1.125, Height 0.312 the other is ID .625, OD 1.128, Height 0.25.

So here is the problem I ran into, I pulled the seal on the gearcase head, cleaned and proceed to put the replacement seal and found out the it's too small. See attached pictures. I measured the ID of the gearcase head where the seal fit into and it's 1.25". Looking at all the dimension listed on Sierra website there is not one that have an outer diameter of 1.25" with an inner diameter of 0.625. The closet one would be 1.375" with 0.625 ID. I am not even sure if I should order this seal and try it out?

Anyone ran into this issue before, please help.

Thanks
Anthony

 

[HighTrim]

The earlier gearcases, 1951 to 1957, 10 to 18hp, had the 1.25" OD seal on the propshaft, with a .625" shaft and .313 width. They are No Longer Available from Sierra. It is part number 302495.

If you have trouble locating one, message me.

 

[F_R]

I am sitting here holding a gearcase head in my hand. It is 1 1/4" dia (ruler measurement). Another one I'm holding is 1 1/8". I think I know the answer, but let me do some checking and get back with you.

 

[F_R]

The gearcase head and seal were changed mid-year 1957. The older design was the larger one, 1 1/4" dia., part number 302495, no Sierra interchange.

The change was to 1 1/8", part number 302545, which was further changed to 313284 (Sierra 18-2005).

302495 is available from dealers at a hefty price. Better take High Trim up on his offer, whatever it is. Your other options are to replace the whole gearcase head, or if it were me, I'd fabricate a reducing sleeve to go in it (easy for me to say because I have a lathe).

 

[antnida]

Million thanks Chris, no wonder I kept looking at my model year and up, I did went down to 1958 but could not find one they were all replaced with the new gearcase, I am not sure if the previous owner did a swap or not or OMC just used up old parts in this '64 outboard.

One more question . Since this part is no longer available and some dealers have it because they're sitting on old stock, would you recommended that I replace the gearhead to a later year so when I need to tuneup the lower unit I can utilize the smaller seal that are readily available.

Saw one on ebay for $21 0383757 1968 Johnson 20 hp FD-22E J2971752

Thanks
Anthony

The earlier gearcases, 1951 to 1957, 10 to 18hp, had the 1.25" OD seal on the propshaft, with a .625" shaft and .313 width. They are No Longer Available from Sierra. It is part number 302495.

If you have trouble locating one, message me.

 

[antnida]

I would like to upgrade the new gearcase head so that the new part is readily available when needed. Suck part is I have a crabbing trip in 3 days and while it's only 2 mile from the launch and 2 to get back, using the trolling motor can take awhile.

 

[F_R]

Million thanks Chris, no wonder I kept looking at my model year and up, I did went down to 1958 but could not find one they were all replaced with the new gearcase, I am not sure if the previous owner did a swap or not or OMC just used up old parts in this '64 outboard.

One more question . Since this part is no longer available and some dealers have it because they're sitting on old stock, would you recommended that I replace the gearhead to a later year so when I need to tuneup the lower unit I can utilize the smaller seal that are readily available.

Saw one on ebay for $21 0383757 1968 Johnson 20 hp FD-22E J2971752

Thanks
Anthony

Is that for a new one? If so, it is a steal at that price. List price is $167.34. But I wouldn't pay that much for one unless it was the last one on earth (it isn't).

The main reason they changed the diameter was because the aluminum surrounding the larger seal was pretty thin, and subject to stretching and or cracking. For the price, I'd change it.

 

[antnida]

Is that for a new one? If so, it is a steal at that price. List price is $167.34. But I wouldn't pay that much for one unless it was the last one on earth (it isn't).

The main reason they changed the diameter was because the aluminum surrounding the larger seal was pretty thin, and subject to stretching and or cracking. For the price, I'd change it.

It's for a used one, can't beat that price. I bought it so now I just wait for the gearcase head to arrive.

One more question instead of creating a new post, I didn't see the thrust washer under the pinion gear, I got another washer that fit would that be okay or I need to order the oem part?

Thanks
Anthony

 

[F_R]

Since it seems possible that it may be a pre-'57 gearcase, it may not require a pinion thrust washer. However, if it does require one, you must use the correct one because the thickness is critical (controls the gear lash). You will have to lay the parts in the case to see. If it is supposed to have one, but doesn't, the gears will be way too loose.

 

[nwcove]

antnida, is there a bearing dealer in your area? they will also sell seals, usually for much much less than oem. if so..give them a call .

 

[HighTrim]

I would first determine what exactly you have there.

Almost all of the prop shaft assembly differs from the earlier '51 to '57 gearcase, to the later mid 1957 and on 18hp

The only similar items I can think of off hand internally are the forward gear bushing, the cradle, and the cradle lever.

The gears, dog, prop shaft, head, etc.. all differ.

SO, did someone change the whole gearcase, or just the prop shaft assembly. That would be good information to know. My GUESS is that you have a early '57 or earlier gearcase, as you do not have the thrust washer at the pinion gear.

 

[antnida]

I don't have any detail on what happened to this '64 outboard and why it have a older gearcase, the paint matched throughout the outboard, the previous owner told me that he did a carb job, change the impeller, and lower unit oil. A month later I rebuild the carb and it was cleaned however, non of the old parts was changed, impeller is new & lower unit leaked. Being a newbie I didn't know what else to look for beside that its start, idle, going forward and reverse and spiting out water just fine so i assumed it was serviced, however, I learned a lot through all this.

I received the "new" gearcase head I got from Ebay and it fit the new seal perfectly. One less thing to worry about when ordering new part. Reading all of yours replies I believed this is an older gearcase unit and does not have the thrust washer at the the pinion gear. I got a tube of 3M 847 so I'll start to put things back and do a pressure test to see if it leak.

Should I applied 3M 847 around the screws and o ring too?

Some pictures of the gearcase, I saw part number 302492 but no info on the web for that part.

 

[antnida]

More pictures, don't know why when I rotated the image and saved, it won't upload.

 

[AlTn]

yes to the screws and oring...you can glue your spaghetti seal into it's groove and set it aside while assembling the other pieces as the 847 will reactivate when it comes into contact with some fresh 847 so you don't have to rush through the reassembly fearing the 847 will dry out before you can complete it. That 847 flows quickly so be forewarned...a little goes a long way and try not to put so much that it will flow out into the gear case when the skeg is mated up. Also, don't be afraid to use and impact driver if you have a pressure leak between the skeg and gear case surfaces.

 

[HighTrim]

This should help too

 

[AlTn]

HIGH nails it again....Sealer 1000 = 3M 847....step F. pay particular attention to the instructions concerning the end screws first and later the center screws when jointing the skeg and case...I tried with all 6 screws in place and working from the center screws out in a torque sequence...skeg never did mate properly and tried to slide to one side...if you have to "go back in" after getting it together acetone on a rag works on removing the 847...it's just clean and reassemble , all a part of the learning process

 

[antnida]

Thanks you all for helping out a newbie, I did have to take it a part, re-clean and reseal again due one extra pin that I left out (the shifter lever pivot pin). I did a pressure test and spray the gearcase with soapy water, no leak anywhere else except for one leak coming out of the propeller seal (the shalf is very nice and smooth, I didn't see the seal have any imperfection either). What can I do in this case?