johnson 9.9 lower unit seals and other questions.

Hi all. <br /><br />My 1981 johnson 9.9 is leaking a bit of gear oil from the drain hole in the front of the LU, I have known for a little while that there was a little water intrusion but this is the first time i've seen oil leaking out.<br /><br />anyway, i am going to do a seal replacement (all of them) on the LU. I have a manual, but it doesn't really explain to me how to change the seals on the LU. it's more of an all-or-nothing rebuild explanation. so my question is this: do i need to buy another manual (i have a SELOC manual now) or is there some other resource where i could get good instructions? ( this has been VERY helpful but it doesn't cover the LU<br /><br />one final question. if i get a factory manual for say a 1975 or 78 on ebay, will it be mostly or completely relevant for my 1981? any differences?<br /><br />thanks, and great forum<br /><br />matt

Re: johnson 9.9 lower unit seals and other questions.

whosmatt,<br />Rebuilding the lower unit is not all that difficult. Take your time and identify the sequence in which things are disassembled. I did a lower unit about 3 months ago and I found that a digital camera works wonders. I photographed each componant before it was disassembled so I had a good reference point. <br />The whole thing should come apart rather easily. You may need to use a hammer to pop the seals out. Dont worry about their condition, but focus on NOT damaging any of the other parts in the process <br />Dont be afraid...after all its only metal, oil and rubber...<br /><br />Nav

Re: johnson 9.9 lower unit seals and other questions.

well, i'm not really looking to rebuild, just replace the seals. i'd like to do it with a minimum of disassembly, like just dropping the lower unit. i don't want to have to take the whole damn thing apart

Re: johnson 9.9 lower unit seals and other questions.

Where is the leak? <br />You don't have to tear the lower unit apart if is just the fill screw washers. I change my washers everytime I change the oil. <br />A new impeller is a must if you decide to tear it down anyway.<br /><br />Have fun!

Re: johnson 9.9 lower unit seals and other questions.

i think that the leak is either in the shift rod seal or the drive shaft seal, since the oil is coming (in very small amounts) from the small (water) drain hole in the front of the LU. I just replaced the water pump a few months ago, so i think that part of it will be fine. like i said, removing the lu is no problem, i did that once when i installed the new water pump. I just don't want to have unnecessarily disassemble things. I'd like to know before hand what needs to happen. if there is too much work involved or if it requires special tools that i do not have, i will have a professional do it.<br /><br />thanks <br /><br />matt

Re: johnson 9.9 lower unit seals and other questions.

whosmat,The shift rod seal is easier than the waterpump assy. you've already changed.If you tackled that job shift rod seal should be a snap.Consider changing propshaft seal while your at it.

Re: johnson 9.9 lower unit seals and other questions.

thanks..<br /><br />ok, i will get a seal kit and try it myself. how about the driveshaft seal?? can i just pull the driveshaft out and change that seal? <br /><br />what has to come off to change the prop shaft seals? those look pretty good (at least what i can see with the prop off) but i might as well replace them now.<br /><br />in short, what i want to know is can i just pull the LU like i did for the water pump change and replace the seals with it off, or do i actually have to take it apart once i have it off?<br /><br />the manual that i have really is not very much help in this matter the lower unit section is geared (no pun intended) towared a complete rebuild rather than just a seal replacment.<br /><br />if someone can recommend a resource that details this process step-by-step (illustrated would be great) i would buy it for sure.<br /><br />matt

Re: johnson 9.9 lower unit seals and other questions.

matt,You'll need 1/4 or 3/8 drive long extension and socket to remove carrier bolts for changing propshaft seals.Once you remove prop,look into void behind it to locate.Also may need a puller to remove seal carrier.If your manual discusses complete rebuild of unit it has to touch on these since that is part of the disassembly procedure.Same with driveshaft seal.

Re: johnson 9.9 lower unit seals and other questions.

ok, after looking more at my manual, it appears that the bearing carrier can be removed from the LU w/o removing the prop shaft. that should make that one pretty easy.<br /><br />any harm in yanking the driveshaft out of the top? i accidentally did just that when i was replacing the water pump, but i have also been cautioned about it.<br /><br />i think i have a handle on it now.<br /><br />thanks<br />matt

Re: johnson 9.9 lower unit seals and other questions.

I suggest hitting your local library for the manuals. Usually they have several by different publishers and the content also varies. One of them may show you the detail you are looking for.

Re: johnson 9.9 lower unit seals and other questions.

thanks for all the replies here. i have one more question:<br /><br />will this puller set serve me well? I understand that this is what i need to get the carrier out, as well as pull my flywheel if (when) the time comes.<br /><br /> http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=37714 <br /><br />thanks,<br /><br />matt

Re: johnson 9.9 lower unit seals and other questions.

Whosmatt<br />My motor is a 1974 15HP Johnson. This year I change all the seals and changed from short shaft to long shaft.<br />Very normal to get oil out of lower unit holes if been useing motor for trolling but this oil is unburned motor oil not lower unit oil. Usually very black not milky like lower unit oil with water in it. If you are getting water in oil I would first check the fill and drain plug seals.<br />I think Prop shaft seals leak more than the drive shaft seals. If it were me I would change them first. Drain the oil, Remove the prop, remove the two screw that hold the bearing hub to gear case.<br />Use a small screwdriver to get bearing hub started coming out. Push in on the prop shaft and pull the hub. Coat new seals outside with a bearing sealer and replace the two prop shaft seals and the outside oring and put it back in. Be carefull not to damage the bearing. The drive shaft seals same as changing the waterpump to start. After pull the pump pull the drive shaft out. Reach inside the seals with something to pull seals up and out. Coat the new seals out side with a gasket sealer and reinstall. Put back the drive shaft. Make sure the water pump plates are correct and sealed so can not force water down into drive shaft seal area. Put it all back together. The shift shaft O ring I dout will be problem but note height of shift lever and which gear it is in. Unscrew it then pull the Oring and washer. Put in new Oring then washer. Screw the shift lever back in the same distance and you are all set to reassemble. <br />Also check this site some good info here.<br /><br /> http://www.pugetsoundanglers.org/Fishing Info/Johnson 9.9_15.htm