Short shaft Alpha One question

[natemoore]

The groove in the short shaft looks so clean and sharp that I wonder if it is machined into the shaft. Up close it looks like a perfect v-groove of consistent width and depth around the entire circumference. No rust or pitting in the groove either.

So, would a new short shaft have a smooth seal surface or is there indeed a groove machined into it?

I know I can get a speedi-sleeve if it is supposed to be smooth.

 

[TowRoper]

Re: Short shaft Alpha One question

looks like its just from the machining process to me ive seen that mark b4

 

[Bondo]

Re: Short shaft Alpha One question

Ayuh,... It's Supposed to be perfectly Smooth.... No Groove...

 

[natemoore]

Re: Short shaft Alpha One question

Ayuh,... It's Supposed to be perfectly Smooth.... No Groove...

It looks like this groove was caused by the dust lip. The actual seal with the garter spring is riding on smooth, shiny metal.

I'm okay then, right?

 

[Bifflefan]

Re: Short shaft Alpha One question

Believe it or not, the rubber on the seal will eat away at the steel until you get a groove in it.
For a cars front main seal they make a "Speedy Seal" kit that has a small round band that fits over the crank sealing area to give you a new flat surface for the seal to ride on.
As for an outdriver i dont know if there is such a thing, but id look in to it unless you already have a new shaft.

 

[ziggy]

Re: Short shaft Alpha One question

I'm okay then, right?

i don't know really. i do know that bondo is right. a new one is perfectly smooth w/no grove. i suppose ya could use the old one and put it together and pressure test it. reckon you'll do that anyways. if it leaks, you'll know you shoulda replaced it like dons' sig says...

Why is there never enough time to do it right the first time,
But always enough time to do it again?

or ya can replace it now.
like i said i don't know if it'll seal or not. i do know a new one will though.. mine was worse than yours, it got replaced and it sealed...

 

[jtybt]

Re: Short shaft Alpha One question



That's an oil seal lip! If the groove is shallow it can be chucked in a lathe and smoothed with emery cloth.

Another trick is to re-position the seal so the lip rides in a different spot. They actually make seals with different width 'bodies'. You can also shim the seal .030".

 

[Bondo]

Re: Short shaft Alpha One question

I'm okay then, right?

Ayuh,... Like Ziggy said,...
Replace it Now, while it's apart,...
Or,..
Replace it later, after you've put it back together....

The part you posted thepicture of is Not Right...

 

[natemoore]

Re: Short shaft Alpha One question

Ayuh,... Like Ziggy said,...
Replace it Now, while it's apart,...
Or,..
Replace it later, after you've put it back together....

The part you posted thepicture of is Not Right...

You're recommending I replace it even though I said that the oil seal lip is riding on the smooth, shiny portion of the shaft? The dust lip is riding on the bad area, but it doesn't keep oil in. I assembled the gears then carefully pulled the shaft off along with the oil seal carrier to verify the seal's location.

 

[JustJason]

Re: Short shaft Alpha One question

You're recommending I replace it even though I said that the oil seal lip is riding on the smooth, shiny portion of the shaft? The dust lip is riding on the bad area, but it doesn't keep oil in

How do you know which part of the seal is riding on which part of the yoke? When its all together you cannot see it.

There are 3 parts to forming an oil seal.
1. the oil itself... a seal needs oil behind it to cool the seal or else the rubber burns and the spring starts to poke through, which is what happened to you. You ran low on oil.
2. The oil seal
3. the machined surface that the seal rides on, and yours is bad.

If 1 of the 3 are off you no longer have a good oil seal. Sure you can screw around with speedi-sleeves or putting your yoke in a lathe to smooth it out. But once you get it together and find out its still leaking, spending the 80 bucks on a yoke would have seemed the the smartest idea from the start.

 

[natemoore]

Re: Short shaft Alpha One question

How do you know which part of the seal is riding on which part of the yoke? When its all together you cannot see it.

Am I missing something?

1) You can see the dust lip location on the short yoke from the outside, then derive the location of the oil lip since you know the distance between the dust lip and the oil lip, or

2) You can put the assembly together, then keeping the seal carrier and yoke together, pull the rest of the stuff away, revealing where the oil seal is riding, as I indicated with the arrows, or

3) You can put black permanent marker on the shaft, assemble the unit, spin the shaft a few times, disassemble, and see where the seal rides (where the black is worn off).

This is how I verified the placement of the two speedi-sleeves I had to use for the two camshaft seals.

... a seal needs oil behind it to cool the seal or else the rubber burns and the spring starts to poke through, which is what happened to you. You ran low on oil.

I have the old oil seal. It wasn't burned and the spring wasn't poking through. It may have been leaking since I found foamy grease inside the u-joint bellows, although there was no water in the gear oil. I'm just preemptively replacing the seal since I have the drive off (also installed a new transom service kit).

 

[JustJason]

Re: Short shaft Alpha One question

I have the old oil seal. It wasn't burned

If it wasn't burned then you wouldn't be leaking oil. Only needs to burn a couple thou of an inch to leak.

 

[natemoore]

Re: Short shaft Alpha One question

If it wasn't burned then you wouldn't be leaking oil. Only needs to burn a couple thou of an inch to leak.

This isn't even the issue. I'm being told that I should replace the shaft anyway even though I can confirm by using several different methods that the oil seal is riding on the smooth, defect free portion of the shaft. This doesn't make sense to me.

 

[Apollo75]

Re: Short shaft Alpha One question

These mechanics err' on the safe side --- maybe to keep the boat floating

That little grove --- see if the seal or what ever rides there is tight ---- if it is an oil seal put some lube on it and put that boat back together.

Probably take a act of God to get that seal in the exact same place to ride there anyway

Quit looking for problems --- get out and use that boat

If I disassembled my boat I bet I could find more problems than I could fix by next year


Happy Boating

OFM

"If you get a couple torpedoes slammed into yer sides ---> You have my permission to panic."

 

[Bondo]

Re: Short shaft Alpha One question

I'm being told that I should replace the shaft anyway even though I can confirm by using several different methods that the oil seal is riding on the smooth, defect free portion of the shaft.

Fine,... Run it then,.... It's Your boat.....

These mechanics err' on the safe side --- maybe to keep the boat floating

Nope,.... This Mechanic prefers to do the job just Once,+ do it Right....

 

[Apollo75]

Re: Short shaft Alpha One question

Another trick is to re-position the seal so the lip rides in a different spot. They actually make seals with different width 'bodies'. You can also shim the seal .030".

Natemoore

Part of being a mechanic is making the call whether a part is serviceable.

I say put on a new seal and put it back together.

Your call


Best Wishes

OFM

"If you get a couple torpedoes slammed into yer sides ---> You have my permission to panic."

 

[wca_tim]

Re: Short shaft Alpha One question

so here's the deal... the dirt that got in there has over time ground a groove into the sealing surface... it probably doesn't ride in the same place you think it does once it's hot and full, etc... remember that the air in your sealed drive expands and contracts as the drive heats up and cools.

so what... well, if it leaks a little... the fluid leaks into the bellows. again no big deal, right? until it gets low and the upper gears burn up. or if there is water intrusion into the ujoint bellows, water leaks into the drive... and the upper gearset burns up. either way I think it's a pay me now or pay me lots more later situation... imho.

 

[natemoore]

Re: Short shaft Alpha One question

Mechanic: "You need to replace this short shaft because of this rust rye-cheer."

Me: "But isn't the oil seal lip riding on this clean, smooth, shiny portion of the shaft?"

Mechanic: "You know, you could have gear failure if this thing leaks."

Me: "But why would it leak if the oil seal lip is on this smooth, shiny, brand new looking portion of the shaft?"

Mechanic: "But a new shaft is supposed to look like this. Besides, it's only $80."

Me: "Are you saying that the oil seal is going to leak even though it is riding on a perfect looking portion of the shaft."

Mechanic: "Better safe than sorry. Pay me now or pay me later."

Just summarizing this discussion.

The seal is not going to leak.

Thanks for the input, though.

 

[JustJason]

Re: Short shaft Alpha One question

The seal is not going to leak

See ya in a week!!

 

[Howard Sterndrive]

Re: Short shaft Alpha One question

Believe it or not, the rubber on the seal will eat away at the steel .

I've heard so many techs say that but it's not really the case...

Rubber cannot cut steel.

What machines that groove is abrasive particles stuck in the seal lip as wca tim mentioned.

When oil is leaking out, abrasives get trapped there.

The reason that looks so perfectly machined is because it IS

The abrasives can include hardened bearing steel from an antifriction bearing. Just like a machinists tool. The shaft spins at thousands of rpm just like it's on the lathe.

$80 shaft would be purchased if it were me. Or at least a stainless speedi sleeve for $25.

Sometimes you can shim the seal to ride in a different spot. but for $80 who could be bothered. not even a tank of gas.