1957 Johnson 7.5 hp prop seal removal

[riverrat 2]

Is there a correct way to remove the seal right behind the prop. I just noticed about a half a cup of gear lube on the garage floor and when I checked as I had the prop off that it is coming from that seal. Any hints would be appreciated It seems like it is one thing after another with this motor while I'm waiting for parts to come I find another surprise' Also is there a neat way to clamp all the little hoses i have had to clamp. I used small circle clamps and I don't like the way they look.

 

[kfa4303]

Re: 1957 Johnson 7.5 hp prop seal removal

hi riverrat. the oil seals are removed using a standard automotive oil seal puller. It's not uncommon for fishing line to get caught on the prop shaft and cut into the seal. Here are some handy links that can walk you through the job. they're for a slightly different model, but all of the basic steps are the same. you can get a new reseal kit right here at iboats for about $25.

http://forums.iboats.com/johnson-ev...l-kit-1968-evinrude-fastwin-18-hp-601481.html
http://forums.iboats.com/johnson-evinrude-outboards/fastwin-lower-unit-seal-faq-277190.html
HOW TO PULL SEALS FROM LOWER UNITS - YouTube

 

[riverrat 2]

Re: 1957 Johnson 7.5 hp prop seal removal

Hello Vice Admiral; Is there anyway I could do a prop shaft seal without dropping the lower unit and taking it all apart . I'm a little gun shy of doing a full lower unit seal repair with a kit. I would kind of like to get into easy without having to jump in with both feet all at once. If u know what I mean. I will if I have too but would rather not. U guys have been a lifesaver to me so far and I thank u and all the others for their help' Thanks again, riverrat 2

 

[kfa4303]

Re: 1957 Johnson 7.5 hp prop seal removal

Hello again rat. I'm afraid you it's sort of an all or none deal, so you'll need to drop the LU and disassemble the gearcase in order to change the seal. Don't worry, it's really not that bad. The key is to go slowly and take lots of reference pics as you go. It's actually kind of fun. You'll learn tons which will help to demystify your motor greatly. Plus, you'll be able to rest easy knowing the job is done right. I would go ahead an order the reseal kit which is only about $25 here at iboats, then begin disassembling the LU. That way you have several days to tinker and learn until it arrives. Besides, the hardest, most time consuming part is getting the old seals out any way. The new ones install in about 5 min. The only special tool you need is an automotive oil seal puller along with a tube of Permatex Ultra Black gasket sealant and a quart of gear oil, all of which are under $10 and available at any auto store/Wal-mart. We're here for ya' if it gets weird. Just holler if you get stuck. You can do it!!!

 

[riverrat 2]

Re: 1957 Johnson 7.5 hp prop seal removal

Hello Vice Admiral; Do u know if that is the complete kit or do I have to order the prop seal seperate? Thanks againfor all your help I'm sure I will need your expert advice in the future when I get my hands dirty.

 

[kfa4303]

Re: 1957 Johnson 7.5 hp prop seal removal

All the seals will come together in a complete kit. I believe this is the one you'll need.

Lower Unit Gear Housing Seal Kit for Johnson/Evinrude, GLM 87604 - Sierra - iboats

As you can see, there's really not much to it. It's even easier than the other links I posted for the 18-20hp models. If your budget will allow, you may as well get a new impeller too. That way your entire lower unit will be good to go for a while.

Water Pump Impeller for Johnson/Evinrude 277181 434424, GLM 89580 - Sierra - iboats

 

[riverrat 2]

Re: 1957 Johnson 7.5 hp prop seal removal

Hello again Vice Admiral; I took your advice and ordered the seal kit and the impeller kit from you. I'm getting all my help from you so why go somewhere else for parts. (I'm not that kind of guy anyway). quick question when the time comes besides putting permatex around the seals before putting them in. Do I put it on the spagetti seal and o rings or do I just lubricate them with oil? Thank you I'll wait for your expert reply while I'm waiting for all the goodies to arrive. Thanks Again, & have a nice weekend---riverrat 2

 

[kfa4303]

Re: 1957 Johnson 7.5 hp prop seal removal

Hello again rat. All of the o-rings install dry, without any sealant, but you will need to apply a generous amount to the entire length of the spaghetti seal and on both halves of the geagrcase clam shell. Also, Make sure you put plenty around the bolt holes that hold the two halves of the gear case together as well. You should get a fair amount of sealant oozing out when you tighten down the bolts.

 

[riverrat 2]

Re: 1957 Johnson 7.5 hp prop seal removal

Thanks for your quick reply. I'm not too worried about the seal job with u in my corner. Thanks again--- riverrat 2

 

[HighTrim]

Re: 1957 Johnson 7.5 hp prop seal removal

The 303360 O ring requires 3M 847 around its entire circumference. DO NOT install it dry or it will leak. This is where the spaghetti seal abuts and is a common failure spot. That spaghetti seal must be cut square with 1/16" overhang. Any less and there will be water intrusion due to the gap, any more and it will buckle, again causing water intrusion. You don't want to over do it either on the sealant or it will ooze into the gearcase. More is not always better here, but a nice sufficient bead. Dry fit the spaghetti seal first, pushing it to the outer edge of the groove.

Cover the skeg screw threads with sealer, then torque to 5 to 7 ft/lbs, or 60 to 84 inch/lbs in a circular manner as you do a head gasket.

The o ring at the top of the drive shaft gets covered in water proof marine grease. No grease on top of driveshaft though, only the threads and o ring. Inner circ of shift rod o ring gets grease as well. The outer circ of the bushing can get a bead of 3M 847, but not a likely spot to leak. The critical thing here is that you do not over drive the bushing against the o ring. Just until flush with casting in most cases.

 

[Scurvy Knave]

Re: 1957 Johnson 7.5 hp prop seal removal

I'm surprised nobody has mentioned:

1 - make sure that the carbon seal at the top of the driveshaft is in good shape
2- make sure that the carbon seal at the top of the the driveshaft is reassembled in the right order
3- grease the splines (but not the top!) of the drive shaft where it enters the powerhead
4- be prepare to have to replace the gasket between the powerhead and the lower unit. they don't always survive separation

you CAN do it! :encouragement:

 

[HighTrim]

Re: 1957 Johnson 7.5 hp prop seal removal

Base gaskets sometimes survive? lol

 

[Scurvy Knave]

Re: 1957 Johnson 7.5 hp prop seal removal

the last time I changed the impeller on my 7.5, the gasket was 'serviceable' after separation; as in, in a bind I would have re-used it (with some extra permatex hwell but given their ready availability and low cost it really isn't a big deal to do it right