Trying to rebuild 18 hp Johnson

[ccvolsdhf]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

Ok guys I need some help now. Today I'm expecting my last piece for the lower unit. The shift rod cradle. Here's some pics ,and I got a couple questions. 1st pic is everything I got for LU rebuild. 2nd pic Is everything I plan on using at this time. The 2 items still in bags are the drive shaft O-ring and the water tube grommet. That I will install when reattaching the lower unit. The rest of the stuff appears to be extras. 3rd and 4th pics are showing widths of drive shaft seals. 5th pic shows the actual amount or rubber in the drive shaft seal. 1st question is about the 3m 847 to which parts ,and how much should I use. IE heavy,med,light. 2nd ? what is the best way to reinstall the seals. 3rd ? is the seals themselves they are smaller in height than the ones I removed. The prop shaft just a little ,but the drive shaft one appears to be only about half as tall as the original, and there is vary little actual rubber inside it. I was sent 3 seals this size. My question is do you guys think I should use 2 of these seals in the drive shaft hole as that appears to be about the height of the original seal. I plan on installing these parts. Shift shaft o-ring and seal,prop shaft O-ring and seal, spaghetti seal, drive shaft seal and water pump plate, housing and Impeller. Of coarse as well as reassembling the LU gears ,and installing drive and shift shafts,plus filling with gear oil. So any tips for any of this stuff would be appreciated. Thanks in advance for any help.

 

[HighTrim]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

You do not need alot of the 847 in most cases. A thin stream around the circumfrence of the drive shaft and prop shaft seals will do it, the excess will only get squeezed out anyways as it is a tight fit. It is sticky stuff, keep a rag close at hand

I also put some around the circumfrence of the bushing for the shift rod seal. Tap that in until it is flush with the casting.

Cut the spaghetti seal 1/16" too long on either end to ensure proper seal, it will "push" in when you close it all up. This is where I am more liberal with the sealer. I put it on the o ring, the spaghetti seal, the gearcase screws, etc...

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Thanks. Chris

Any opinion on weather to use 2 of the seals on the drive shaft or just go with the one having it be about
Half the size of original

 

[HighTrim]

Re: Trying to rebuild 18 hp Johnson

IF you are certain you have the correct seal, that is all that is needed. What part number did you get?

 

[1946Zephyr]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

Wow! that's A neat looking little motor. It just screams vintage. To thank that's its basically brand new, Yet that old is cool. It no doubt will be more reliable than anything made new today. ( Historical preservation of art and functionality) cool stuff I like it

Actually the one on the left is mine. The one on the right is one I found at nymarine website. I plan on buying paint from him to paint mine, so mine should look as good as his. Right now, I have most of my parts zinc chromated and ready to paint. But yea, they are cool looking little motors. I can't wait to try it out this Spring, when I get it back together. The internals of the top end are brand new and the crank journals in the block look untouched, so it should run pretty nice. The old pistons and rings gave me 60 psi on both cylinders, but the lower rod journal was watermarked and the pistion was slightly scored. So, I went ahead and replaced everything inside.

 

[1946Zephyr]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

Cool, gettin the lower end back together, huh? It looks like you're doing a fantastic job. Keep up the good work.

 

[kfa4303]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

HI cc. Here's a link that can walk you through the job. High Trim is right about the 3M 847, a little dab' do ya. double check the seal number in your parts manual and cross-reference it with the part number stamped on the the seal. It's small, but it should be on there. I once had a 10 hp with some Farankensteined parts on it, so I actually had to get 2 diff kits to get the right combo of seals, but again that was a Frankenstein. I've always had great luck with Sierra brand replacement parts. Assuming you ordered the right kit, you should be ok.

http://forums.iboats.com/showthread.php?t=277190&highlight=lower+unit+seal+kit+installation

 

[ccvolsdhf]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

I actually ordered the Mallory kit 9-74105 which says it replaces 18-2684. Those are the numbers Iboats gives for 59 18hp Johnson. The sierra kit 18-2684 did not show the pivot pin O-ring. So I went with the Mallory kit. There are no numbers stamped on the seals so IDK. I will look up the part # in the parts manual and see if I can order just that seal. These seal are defiantly half the height and appear to have less rubber martial inside. I'm thinking maybe just advancements in technology have these seals not needing to be as beefy as there once where. As I'm sure I have the right kit for my motor, and It seems unlikely the drive shaft seal is wrong in the kit. Also just realized mail doesn't run today so looks like tomorrow or later if I order new seal. Thanks guys... I'll check out the link and take it easy with the 847

 

[ccvolsdhf]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

Ok so I checked the parts book part # is 41-62 wierd. In an Iboats thread someone said that goes to this Sierra part # 321788 which when looked up says it goes to 18hp johnson and it says measurements are
O.D 1.000
shaft size .500
width .188

That's what the seal from the mallory kit measures 1 inch O.D, half in I.D and about 5/32 width or tall. So I gusess the seal just got shorter. I would say this will make seating the seal all the way down a little harder as I won't be able to just knock it flush with the housing, But will have to get something down inside the housing a little bit. I'll post some pics when it's all done.

 

[nwcove]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

i have been looking at resealing a lu, and it shows two seals (sierra) for the prop shaft and driveshaft, i called the local omc dealer and they say its only one for the prop shaft. marineengine.com shows a close up of the two seals on the propshaft and how to face them..id go with the two seals, if both add up to the original thickness.

 

[ccvolsdhf]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

nwcove My prop shaft seal appears to be vary close to original size. The kit came with only 1 seal that would fit the prop shaft. The drive shaft seal on the other hand came with 3 seals of that size and it appears that 2 of them put together would match the originals size. I'm going to try and look now ,but if I can't find it how did it show to face them cause i was wandering if I put 2 in how to put them.

 

[kfa4303]

Re: Thinking of trying to rebuild 18 hp Johnson

Re: Thinking of trying to rebuild 18 hp Johnson

Hi cc. I've never heard of the double seal trick and the kits often come with extra parts that aren't particular to your model, so I'd be a little leery, but others may chime in. This may help.

http://forums.iboats.com/showthread.php?t=277190&highlight=lower+unit+seal+kit+installation

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

Thanks kfa.... I've seen that link a couple of times its good,but there is actually little infomation on reinstalling the seals
I'm not really sure what to do I was set on just installing the one seal till nwcoves post. Nw is there any way you could post us a link
To what you saw at marine engine

 

[HighTrim]

Re: Trying to rebuild 18 hp Johnson

I checked the marine engine site, I only see the 1 seal?

Regardless, I have done a few 18s and have never stacked a seal. But I have also never bought a Mallory kit, so who knows what they do?

 

[kfa4303]

Re: Trying to rebuild 18 hp Johnson

Hi cc. Here's a link to the parts manual for the motor. ('59 18hp)

http://www.marineengine.com/parts/v...ntage-evinrude-johnson/377807/37780700001.htm

If you look on page 12 it looks like there is only one seal each for the prop shaft and drive shaft, #40 and #12 respectively. I had a '61 10 hp which was very similar to your motor and I have a '66 20 hp that is also very much like yours, and I only used one seal each. However, I used Sierra kits and they seemed to work fine. If the the two, thin drive shaft seals will both fit/set properly beneath the water pump housing, I don't see how it could hurt anything to use both. If you decide to go that route, I would put them in "back to back", rather than stacking them with the same orientation. There should ultimately be only one oil seal for the prop shaft as well as a med sized o-ring that goes around the propshaft bearing (#41 on page 12). Next will be the long, thin spaghetti seal that goes between the upper and lower halves of the gear case. You'll then have 1-2 driveshaft seals that are seated below the water pump housing. There is also a small, fairly thin o-ring that goes on the top of the driveshaft and the shift rod seal which is the little fat o-ring in the kit. The super tiny, thin o-ring goes beneath the phillips head, shift rod pivot screw. That's really all there is to it. A bit of vaseline on the spines of the top of the drive shaft will help the o-ring slip on without chaffing and a bit on the tip of the lower shift rod will help it pass through it's o-ring more easily. I usually use a socket that is the same size as the oil seal I'm installing and tap on it lightly with a hammer to seat the seal evenly on all sides at once. Holler if you get stuck.

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

I checked the marine engine site, I only see the 1 seal?

Regardless, I have done a few 18s and have never stacked a seal. But I have also never bought a Mallory kit, so who knows what they do?

What's up Chris....I checked the sierra kit seal and it appears to measure the same as the one in my Mallory kit. So when you did your 18s did the drive shaft seal fit flush with the top of the housing/bushing. I'll post some pics to show what I'm talking about.

 

[nwcove]

Re: Trying to rebuild 18 hp Johnson

the motor i am refering to is a newer one, but it does show how to orient double seals, and does show two seals on the prop shaft, the local omc dealer says no....it only uses one on the prop shaft, but does use two on the drive shaft. ( could be apples and oranges with newish compared to oldish)

 

[ccvolsdhf]

Re: Trying to rebuild 18 hp Johnson

So the 1st pic shows original seal sitting flush with housing/bushing. 2nd shows seal removed and space left behind. 3rd shows single seal that's supposed to fill that opening flush. 4th shows original seal removed. It's the one on the left(what's left of it) You can see there's more brass and rubber looking material in the one that came out. Than the replacement. I checked the sierra kit and the measurements they give for there drive shaft seal, Are spot on to what this seal in the Mallory kit measures. So I'm at a loss

 

[nwcove]

Re: Trying to rebuild 18 hp Johnson

http://www.marineengine.com/parts/j...=J6RCOB&manufacturer=Johnson&section=Gearcase

different animal, but shows how to orient the double seals.

 

[HighTrim]

Re: Trying to rebuild 18 hp Johnson

The drive shaft seal from a 18hp from 1958 through to the 70s should be as follows:

Part number: 321788
Sierra Part Number:18-2032
Shaft: 0.5"
Bore: 0.999"
OD: 1.003"
Width: 0.188"

Prop shaft seal from a 18hp from 1958 through to the 70's should be as follows:

Part number: 313284
Sierra Part Number:18-2005
Shaft: 0.625"
Bore: 1.124"
OD: 1.128"
Width: 0.25"

Is this what you have?