Lower Unit Full Water - Replace necessary?

[NHStriper]

Re: Lower Unit Full Water - Replace necessary?

Thanks Phill, I have a manual and am following it - Here's where I'm at....bearing carrier, thrust washer, thrust bearing, and reverse gear removed. From what I can see, reverse gear and forward gear looks in good shape. The pinion looks pretty good except that a couple of the teeth have some wear to them. I assume this is fine since it's only 3 out of say 20 teeth. This is as far as I can go for disassembling from the prop shaft side. Manual now says I would need to disassemble from the driveshaft now if I go any further...

As easy as you say it is...is there any point in going any further at this point since I've found the leak and performed a visual inspection from the prop shaft opening? The only reason I can think of to continue is to get a look at the clutch dog, but is it worth the extra effort and risk of screwing something up. I don't want to get into shimming the driveshaft with special tools and gauges...

 

[rpsloan]

Re: Lower Unit Full Water - Replace necessary?

Just my two cents, but since you are this far may as well go all the way and replace rest of the seals. If you don't you'll kick yourself in six months when it leaks elsewhere. I'm not saying it will leak but might as well err on the side of caution.

 

[jim j geezer]

Re: Lower Unit Full Water - Replace necessary?

Full disclosure: I diddle read all of ^that^ - just the OP.

Pull the output shaft of the lower unit and LOOK at it! Run a fingernail down it's length. Feel 'roughness' about where the seals should ride? If so, you have a couple of options: Pricey: Purchase & install (1) a new pair of seals, plus, (2) purchase & install a new output shaft as well.
Cheapskate: (I've done this successfully!) : Clean the output shaft with rubbing alcohol, then apply JB Weld epoxy to "build up" the grooves in the output shaft. Once the epoxy hardens, put the output shaft into a drill press and apply a FINE... metal-cutting file to the epoxy patch(es) to machine 'em down to NEAR the diameter of the shaft. Switch to 1000 grit wet-or-dry (well-wetted, please) on a sanding block to finish the job. (Broken record -->) Purchase & install new seals, then re-install the repaired output shaft.

Did I mention that, It could't hoyt... to wiggle the HELL outta that output shaft to determine if the output bearing is toast?

Good luck!
Geezer Jim

 

[Home Cookin']

Re: Lower Unit Full Water - Replace necessary?

"If it aint's broke, fix it until it is."

I suspect the $1000 quote was for a tear-down, not just seals.

i wouldn't take out any of the parts; just replace the seals. I understand there's a lot to setting them. Or you will be paying that $1000.

I have a Johnson 70 I bought used and found the LU full of water; no harm done.


it takes air to make rust; you are lucky that your LU filled completely with water.

 

[NHStriper]

Re: Lower Unit Full Water - Replace necessary?

Geezer Jim - Is the output shaft the same as the prop shaft? If so, to pull it, I would have to pull the driveshaft out which is what I am thinking I should avoid.

HomeCookin - yes the $1000 was full teardown. I plan to replace the prop shaft seals but would you also replace the driveshaft and shift rod seals at this point even though they aren't leaking? Keep in mind I will be replacing the water pump anyways. I was thinking do the bearing carrier seals, replace the water pump and leave the driveshaft and shift seals alone.

 

[phillnjack2]

Re: Lower Unit Full Water - Replace necessary?

If your going to be checking the water pump then might as well put new seals in main drive shaft at
waterpump and also the shift rod.
you have already done the hard stuff., dont panic about the shimming and all that rubbish, youl be ok just make sure
it all goes back the same way it came out.( but with new seals instead of old ones )!!!!
get a nice piece of board and lay everything out in the order it comes out, then just reverse to put it back in
new seals will be easy enough for you to do , no problem.
if you are sure the seal youve flound is definitely the cause then its nod needed to do the rest, but if one has
gone bad then maybe the others are on the way out as well.
plus you can give any of the bearings a nice clean and then know for sure that the gearbox is gonna be good for
many years to come.
if the prop shaft is badly worn you can alway go to a machine shop and get it redone.
or if you know someone who is good at welding and has a lathe they can do it for you.

i would do all the seals while you have it down this far, you dont have to take the clutch dog out, but again it will
give you chance to make sure no water of metal fillings are lurking in there !!!!

getting the main drive shaft out can be a pain by the way.

keep up the good work


phill.......

 

[brnschoneck]

Re: Lower Unit Full Water - Replace necessary?

that sounds good to me ... I may be looking at the same thing idk yet ...i dnt think id tackle the whole shot with the measuring n such but thats just my .02 cents huh !!!! oo i sure learned a lot from this post thanks

 

[brnschoneck]

Re: Lower Unit Full Water - Replace necessary?

If your going to be checking the water pump then might as well put new seals in main drive shaft at
waterpump and also the shift rod.
you have already done the hard stuff., dont panic about the shimming and all that rubbish, youl be ok just make sure
it all goes back the same way it came out.( but with new seals instead of old ones )!!!!
get a nice piece of board and lay everything out in the order it comes out, then just reverse to put it back in
new seals will be easy enough for you to do , no problem.
if you are sure the seal youve flound is definitely the cause then its nod needed to do the rest, but if one has
gone bad then maybe the others are on the way out as well.
plus you can give any of the bearings a nice clean and then know for sure that the gearbox is gonna be good for
many years to come.
if the prop shaft is badly worn you can alway go to a machine shop and get it redone.
or if you know someone who is good at welding and has a lathe they can do it for you.

i would do all the seals while you have it down this far, you dont have to take the clutch dog out, but again it will
give you chance to make sure no water of metal fillings are lurking in there !!!!

getting the main drive shaft out can be a pain by the way.

keep up the good work


phill.......

sounds good to me !!!

 

[NHStriper]

Re: Lower Unit Full Water - Replace necessary?

Here's a final update. I ended up replacing the rest of the seals while I had it apart. I cleaned out as much as I could without removing the driveshaft, put it all back together, refilled with lube and reinstalled. So far so good, one weekend into the season, and everything seems to be normal and shifting smooth.

All in all, I learned a lot, took my time, saved a ton a money, and have the proud feeling knowing I did it on my own with the help of everyone on this forum!! Thanks to all.

 

[vtonian]

Re: Lower Unit Full Water - Replace necessary?

I can offer a reason to pull the prop shaft all the way: it is possible for the forward bearing housing to get seriously frozen inside the casing from corrosion. Like someone said, it takes air to rust but mine filled with water like yours and froze up in there but good. 20/20 hindsight, I wish I'd heeded the warning signs (seemed a bit noisy and got progressively harder to shift into reverse), instead of just wondering about them, and torn the whole thing down at the end of last season and inspected everything. Just pulling the prop shaft all the way to look, before it froze, could have saved me having to purchase a replacement LU. I also had some corrosion on the bearings that might have been avoided.

I'd guess you won't have that problem since you seem to have caught it earlier but was I you, I think I'd go ahead and schedule a complete disassembly when you winterize. Just to be safe. New seals are minor, my labor's cheap and the work is enjoyable, it's still messing around with boats. LU's is expensive.