'58 Johnson 18 part #s

[petrolhead]

I'm putting my motor back together and have a couple of problems with the lower unit seals, my local OMC dealer seems to have ordered the wrong ones!<br />Firstly, the propshaft seal that fits in the bearing head is too small diameter, the original was approx 1 1/4" diameter and the one they have supplied (p/n 0313284) is only 1 1/8", does anyone have the correct part # for the larger one?<br />Secondly, the driveshaft seal that fits under the water pump baseplate is much thinner than the original, I'm not sure if this matters?<br />The seal itself is 3/16" thick, but the seat is approx twice that depth, the seal is the correct diameter though (1") and if I press it down fully into the seat it should work OK. The one I've been supplied is p/n 0321788, is that correct?

 

[fireproducts100]

Re: '58 Johnson 18 part #s

iboats has your parts <br />prop shaft seal 18-2001 $5.75 usd <br />drive shaft seal 18-3290 $5.75 usd

 

[Paul Moir]

Re: '58 Johnson 18 part #s

Those numbers seem to check out fine. For the propshaft seal, I find two part numbers used:<br />313284 - 1.125 OD .625 ID .25 Wide<br />321787 - 1.125 OD .625 ID .312 Wide<br />As you can see, not much difference. The closest I can find is <br />321928 - 1.375 OD .625 ID .25 Wide<br />But it's used in mid-80's 20-35hp gearcases.<br /><br />You might want to take your old propshaft seal to the local bearing house, and see if they can find you one like it. Remember, it's got to be corrosion resistant.<br />As for the driveshaft seal, that's fine. And that part number checks out too.

 

[petrolhead]

Re: '58 Johnson 18 part #s

Are you sure about those numbers? According to the list of seals I found #182001 fits a 1.125" shaft and mine is only 0.625", it also has an OD of 1.624" and I'm looking for 1.250".

 

[petrolhead]

Re: '58 Johnson 18 part #s

This is odd Paul, because the seal I was sold as a propshaft seal is the same size as you quote for p/n 321787 (1.125" x 0.312"), but according to the label it's p/n 313284!<br />That's rather irrelevant though because it's still 1/16" too small to fit my bearing head!<br />I was thinking if I can't find a 1.250" diameter seal I may have to turn an adaptor ring, 1.250 o/d and 1.125" i/d, that ought to work OK.<br />As for the driveshaft seal, are you saying that I just press it right down onto the seat, it doesn't matter if it's not flush with the top?<br />BTW my previous mail was questioning the part numbers provided by danielr, not the ones you quoted, our posts crossed over!

 

[Paul Moir]

Re: '58 Johnson 18 part #s

Yeah, I figured that.<br />Just don't drive the driveshaft seal down all the way to the shoulder; leave it flush with the top like the original seal. As long as it's in there squarely, that's all that matters. Of course, if there's a groove in the driveshaft you may want to take advantage of moving the seal slightly into it to avoid the worn spot.

 

[petrolhead]

Re: '58 Johnson 18 part #s

Good idea about moving the seal slightly to avoid a worn spot, I don't think my driveshaft is worn but I'll check it with a micrometer to be sure, may as well take the opportunity to improve the seal if I can!<br />What do you think about my adaptor ring idea for the propshaft seal, good or not? I suspect if the part number checks out OK there's not a lot the dealer can do, they'll just say it's the right part but won't know why it doesn't fit, and I'll have the same problem if I ever need to replace the seal again.