Noisy gear case

[SweeperForce]

Hello,
Today I went to change my prop, and I noticed a grinding noise went I spun the prop in neutral. There was alot of resistance also. I check to make sure the gear lube didn't leak out, and it didn't. In forward the gear engaged and locked the prop. Same in reverse. I never disassemlbed the lower unit except to put in a new water pump, but nothing inside the gear housing. Before I dig into this, what kind of job will I be getting into? What might I look for when I get inside.

Thanks,
Tom

 

[Kohrah]

Ok couple of basics that I've already learned from here.
1) make sure you have a factory service manual for your engine and read and re read any parts that confuse you.
2) before pulling it apart drain gear oil into a plastic bucket than pass a magnet through the oil to check for metal shavings which would indicate gear wear.
3) once you pull the gearcase apart you'll need all new seals (even if they appear good now would be a good time to replace them)
4) keep baggies and a sharpie handy to "bag and tag" parts for ease of reassembly.

That's what I've learned so far. Others im sure will expand on it. A few questions to help us out what year, make, and hp engine are you working on?


Edit: sorry the signature doesn't show with tapatalk just realized it was there my bad
Sent from my DROIDX using Tapatalk

 

[jerryjerry05]

Re: Noisy gear case

Do the oil drain like Kohrah suggested.That OK.Then undo the linkage.Try to find neutral.Then spin prop.If it's still stiff maybe there is fishing line around the shaft(prop off?)Trying to say the control cable needs adjustng.
If the oil comes out real shiny and bits of metal.Then the clutch dog or gears need to be checked.It's fairly easy to remove the bearing carrier if you gave some kind of puller.
You'll need a couple of pieces of 1/4 or 5/16 allthread to adapt the puller.
There are 2 pieces of metal, half moon shaped that hold the carrier in.You need to push the carrier in to remove them. Then the drive shaft comes out.Get a manual for that.
Send me a pm with your e-mail address. I have the 150 manual and can send the procedures if needed.J

 

[Frank Acampora]

Re: Noisy gear case

It's not difficult to open the gearcase and inspect the gears and drive dogs. However, grinding noises are never a good sign and if you first drain the oil like above suggested and do find metal, it will be very likely that you will need new gears at the least.

If you run into trouble with disassembly or assembly, or if you need gears, send me a private message.

 

[robert graham]

Re: Noisy gear case

First thing I'd do is drain and inspect the lower unit oil for water/contamination, metal particles. If water(especially saltwater) leaked into your gearcase it could corrode and pit your bearings and gears causing the "grinding" noise. Like Jerry said, remove prop and inspect for fishing line or similar wrapped around prop shaft causing "resistance" when you turn prop. Good Luck!

 

[SweeperForce]

Re: Noisy gear case

Thanks fellows for all the great information. I will probably be tearing it apart this weekend. I'll keep you posted.

Thanks again,
Tom

 

[SweeperForce]

Re: Noisy gear case

Here is what I found when I drained the gear oil: About 2 ounces of oil wix with water, thats it. I put in a whole quart this spring, now its gone. I see no metal shaving or other debris in the little bit that remains. This motor never seen salt.

 

[Frank Acampora]

Re: Noisy gear case

You really have no choice: You are pretty much committed to disassembling the lower unit. You ran it with almost no oil and some water in it. If it were not making noise, I would say refill with fresh oil and check for where the oil is leaking. HOWEVER: Since it is making noise, If it were my lower unit, I would remove the water pump and lower plate, check the upper roller bearing and replace the seal(s). Then I would remove the spool and check the gears. While I had it out, I would replace the seals (assuming the gears are OK).
Replace the fill/vent seals and the shift rod seal too. Compared to buying a used lower unit, the complete seals will still be cheap.
It is not a long or difficult job and around here the season is almost ended (unless you need the boat for an ark, what with the constant rain) so bite the bullet and do it.

 

[SweeperForce]

Re: Noisy gear case

I removed the bearing cage with a harmonic balancer puller and 1/4 theaded bar. Spent under $25, the puller recommended by Clymer is around $200.
Anyway, when I pulled it out most of the roller bearings fell out. Some of them are in good shape but most of them are broken.
Here are a few pics of what I found.
View attachment 118509
Since the seal was all chewed up I decided to remove the bearing carrage.

View attachment 118510
Most of the bearings were broken or had flat spots

View attachment 118511
As you can see there is alot of gouging and other damage on the inside were the bearings set. I imagine a new cage won't be cheap.

I'll keep you posted about how the gears look.

Tom

 

[foodfisher]

Re: Noisy gear case

Your attachments were invalid. At least to me.

 

[SweeperForce]

Re: Noisy gear case

Here are the pics from my previous post.
View attachment 118535View attachment 118536View attachment 118537
Now I removed the reverse rear bearing carrier retaining rings, then pulled the carrier and reverse gear. The below photos show that they are in spectacular condition.



Tom

 

[Frank Acampora]

Re: Noisy gear case

So, you have found the problem and yes your gears and drive dogs are in good shape--a little wear on the forward gear dogs but still serviceable. The shaft bearing in the spool is not too expensive and neither is the seal. And, since they are outside the gearcase, they are easy to replace.

Now, the question is: since the shaft needle bearings were shot, how does the shaft itself look? Is it clean with normal discoloration and no spalling? Or, is it damaged and needing replacement? Remember" Any significant damage to the bearing area of the shaft will cause shaft wobbling, premature bearing wear, excessive runout, and premature seal wear. --any or all of these conditions.

 

[SweeperForce]

Re: Noisy gear case

The propeller shaft has some scratches in the arera of the spool. I think it will be ok but I'd feel better by replacing it. To do so does the shaft just pull out after I remove the reverse gear? Another major concern is puting the clutch back on the new shaft correctly.
Now is there anything I need to do to the top where the drive shaft is? I removed the water pump and the cover plate. On the underneath there is a black rubber gasket surrounding the boot for the shift rod and a black seal that goes around the dirve shaft. Do those need to be replaced? Inside the lower unit there is a four prong lock with the word "OFF" and an arrow. Do I need to remove that? If so, where would I get the tool to do it? Thanks everyone for your support and help.

Tom

 

[Frank Acampora]

Re: Noisy gear case



OK! So now I know that you have a two piece drive shaft.

You do not need to remove the four lugged threaded bearing retainer unless you intend to remove the lower drive shaft and pinion. This can be a PIA so unless it is needed, leave it alone, The drive shaft seals (there are two) are in the lower water pump plate so you may as well replace them. However, the lower seal is called the drive shaft seal and the upper is called the water pump seal-- both in the same place on the driveshaft so go figure. The shift rod seal (if it is not the bellows) is cheap and again, you may as well replace it. You remove the shift rod and thread a big lag bolt into the seal to pull it out--don't **** up the plastic housing ---please. If it is the bellows retained by an electrical zip tie, then unless it is cracked and leaking, there is no need to replace it. When you go to reassemble, read Karla's posts on lower unit. This one is fussy to get to shift correctly but she did it and so can you.

after you have removed the reverse gear and bearing carrier, the prop shaft just pulls out with the dog clutch attached. The clutch is retained on the shaft by a roll pin and the shaft is splined, so you practically can not get It back on the wrong way--it is obvious..

The slightly difficult part will be replacing the saddle on the end of the shift shaft into the shift yoke. However, since you have the water pump base off, you can see into the lower unit.

The shaft is going to be expensive--even used. Take a couple of quality photos of the damage so we can see if it is at all usable. You may be able to burnish it with some 400 and 600 grit emery. If you can't find one relatively cheaply, send me a private message: I THINK I might have a replacement.

The photos show the relationof the shift shaft, dog clutch, reverse gear and bearing carrier, and spool (from an earlier one piece lower unit.). They also show the brass saddle pivot on the shift shaft. The photo of a smaller gearcase (From a 55, without forward gear) shows clearly the pivot yoke into which the brass saddle pivot inserts.

 

[SweeperForce]

Re: Noisy gear case

Well, I got the prop shaft out, had a heck of a time getting it back in because the shift yoke kept tuning. Here a few photos of the wear area.



Tom