Bearing Preload

[astronutski]

Hey guys, I've got at least one possibly two dumb questions, which will consume my allotment for the year ;-)

1986 Alpha 1 gen 1, I've replaced the water pump in the gear housing, the upper and lower oil seals in the driveshaft housing, left off the Drive Shaft O-ring and installed the large O-ring on the U-joint "stack". But it failed the pressure test miserably, as in, I couldn't get any air to hold, it would come out just as fast as I pumped it in by hand, I needed a second person to spray the soapy water. I am convinced it is coming from the inside of that bearing retainer ring, the 200 ft.lb. castle nut. Not from the thread area, I've torqued that to 200 (using the chart and a 1/2" click torque wrench), but on the inside of that, so I'm thinking the problem is the oil seal #29 on pg 51 in the manual which came in the rebuild kit but I didn't install because of bearing preload issues. (not sure if my link to diagram in manual is working, but it's the link (I think) Chris posted at boatinfo.no)

Dumb question #1: Do I have to set the preload if I remove that nut to replace the oil seal only without touching the bearings? I see there is a preload spec in the manual for used bearings, so I'm thinking once you remove that nut you're not getting out without setting preload either way.

Intelligent question #1: Does this air leak area point to that oil seal in the bearing stack? I can't think of anything else there that could be the culprit.

(In typing all of this I figured out the answer to my second dumb question, so I still have one in the tank for later)

 

[Bt Doctur]

If you remove the nut from the inputshaft and can pull the gear off the shaft and find 2 spacers between the bearings ,then there is no "pre-load" to worry about.
press the old seal out, press the new seal in and reassemble
Pre-load is used when you use a new gearset or doing a GEN II

 

[astronutski]

If you remove the nut from the inputshaft and can pull the gear off the shaft and find 2 spacers between the bearings ,then there is no "pre-load" to worry about.
press the old seal out, press the new seal in and reassemble
Pre-load is used when you use a new gearset or doing a GEN II

AWESOMENESS!!!!

So do you know the torque value for that input shaft nut? All I see in the manuals is a preload setting.

 

[Bt Doctur]

http://www.boatfix.com/merc/Servmanl/6/6A3R3.PDF 70-80 Ft/Lbs
Page 3A-1

 

[Bt Doctur]

The new gearsets say to remove the small spacer and use rolling torque.I have rebuilt many drives and find that using the small spacer with the new gearset and torquing to 75 Ft/Lbs works a lot easier

 

[astronutski]

The new gearsets say to remove the small spacer and use rolling torque.I have rebuilt many drives and find that using the small spacer with the new gearset and torquing to 75 Ft/Lbs works a lot easier

PERFECT! Thank you Doc! Happy day, very happy day!

 

[astronutski]

If you remove the nut from the inputshaft and can pull the gear off the shaft and find 2 spacers between the bearings ,then there is no "pre-load" to worry about.
press the old seal out, press the new seal in and reassemble
Pre-load is used when you use a new gearset or doing a GEN II

Just a quick follow-up because I'm an overly paranoid type-A by nature.... when you say "press" can I interpret that as "hammer the shi!@$ out of"? Because I don't have a press of any sort.

 

[achris]

Don't hammer anything! If you have a bench vice, use that as a press. You will also need to check the yoke surface that the seal runs on, it will probably be grooved, use a speedi-sleeve to 'repair' it, or press the seal 20 thou deeper into the seal carrier.

When you take the bearing pack apart you will see if you have the small spacer in the centre of the bearings. If you don't (and at 1986 I would suspect you will not), then you will need to preform the preload set up.

Chris...........

 

[Bt Doctur]

page 3A-17 in that link

 

[astronutski]

Don't hammer anything! If you have a bench vice, use that as a press. You will also need to check the yoke surface that the seal runs on, it will probably be grooved, use a speedi-sleeve to 'repair' it, or press the seal 20 thou deeper into the seal carrier.

When you take the bearing pack apart you will see if you have the small spacer in the centre of the bearings. If you don't (and at 1986 I would suspect you will not), then you will need to preform the preload set up.

Chris...........

Thanks Chris!

OK, I like the 20 though deeper option. Also, does this sound like my problem? The air is just pouring out the inner area where the retainer nut threads into the housing. Not in the threads, but on the inside, inside from there. Make sense?

And yes I do have a very nice bench vice.

One last thing, where do I find a rolling bearing preload gauge, I'm not having much luck searching on those terms. I have a 1/4" click type torque wrench, but I don't think that will work at all here.

 

[flipbro]

You need a Dial torque wrench.Did you install the big o ring and use permitex aviation on it?

 

[astronutski]

You need a Dial torque wrench.Did you install the big o ring and use permitex aviation on it?

I installed the big O-ring, no I didn't use anything on it except the high performance lube.
The source I was using http://www.boatfix.com/merc/Servmanl/14/14a3.pdf Page 3A-4 doesn't mention using anything on that big O-ring.
I put the lube on it just because that seemed better than installing it dry. Would the permatex solve my huge air leak? I still want to replace that oil seal though because the thing was in storage for 15 years WITH THE DRIVE UP IN TRAILER MODE!!! There was a lot of oil/lube in the UJ bellows so I assume that oil seal is the culprit... make sense?

And from above "20 though deeper option" I meant 20 thou deeper.

 

[achris]

Thanks Chris!

OK, I like the 20 though deeper option. Also, does this sound like my problem? The air is just pouring out the inner area where the retainer nut threads into the housing. Not in the threads, but on the inside, inside from there. Make sense?

And yes I do have a very nice bench vice.

One last thing, where do I find a rolling bearing preload gauge, I'm not having much luck searching on those terms. I have a 1/4" click type torque wrench, but I don't think that will work at all here.

Air from the centre area of the yoke is indicative of the seal, yes.

For a torque indicator (not a click wrench) look at Seekonk. I have the 0-150, but would suggest getting the 0-30 in-lb....

I have posted a video of the procedure. Have a look up in the stickies.

Chris......

 

[astronutski]

Air from the centre area of the yoke is indicative of the seal, yes.

For a torque indicator (not a click wrench) look at Seekonk. I have the 0-150, but would suggest getting the 0-30 in-lb....

I have posted a video of the procedure. Have a look up in the stickies.

Chris......

Thank you Chris, yes I have watched that (and all of your other videos) many many times So thank you for taking the time to make and post them. I can do it no problem, it's just a matter of yet another $150-$200 tool I only need once. If I can get away with just torquing it to 70-80 ft.lbs. that would be ideal. Of course I don't want to do that at the expense of replacing the entire drive down the road! It' might pay to take that stack in to someone else to replace the seal and set the preload, probably end up paying the same $150-$200 LOL, and I wouldn't have the tool!

 

[Bt Doctur]

Well time to take a reality break here , you say you have a Alpha 1 but you reference a Alpha GEN II manual.
So what drive are you working on so we can give you the correct answer?????????????

 

[astronutski]

Well time to take a reality break here , you say you have a Alpha 1 but you reference a Alpha GEN II manual.
So what drive are you working on so we can give you the correct answer?????????????

Sounds great to me! Well, I didn't know this was a Gen II manual, it doesn't say so anywhere that I can see. Can't remember where I found the link but it was in this forum. Ok good, call it a noobie error.
It is DEFINITELY an Alpha 1 gen 1 that I have no doubt. Mercruiser Drive Unit S/N# 0A594520.
MCM 140 Engine# A586281 in case that matters. 1986 as stated above.

 

[Bt Doctur]

#6 is MC1,R,MR, Alpha #14 is for the Alpha GEN II drive
the link I posted is for that drives upper unit. If you remove the nut, and can slide the gear and bearings off the yoke you have a standard gear set that is just torqued to 70-8-0 Ft/Lbs Between the 2 bearing races you will find a small and large spacer ring.

 

[astronutski]

#6 is MC1,R,MR, Alpha #14 is for the Alpha GEN II drive
the link I posted is for that drives upper unit. If you remove the nut, and can slide the gear and bearings off the yoke you have a standard gear set that is just torqued to 70-8-0 Ft/Lbs Between the 2 bearing races you will find a small and large spacer ring.

Ugh, I didn't know that about the #6 and #14! Thank you for straightening me out.

OK, makes sense on the standard gearset I'll find out tonight, thank you Doc!

 

[Bt Doctur]

left a message

 

[astronutski]

Don't hammer anything! If you have a bench vice, use that as a press. You will also need to check the yoke surface that the seal runs on, it will probably be grooved, use a speedi-sleeve to 'repair' it, or press the seal 20 thou deeper into the seal carrier.

When you take the bearing pack apart you will see if you have the small spacer in the centre of the bearings. If you don't (and at 1986 I would suspect you will not), then you will need to preform the preload set up.

Chris...........

Chris, or anyone, I'm at the job and I do have the small spacer thank God, but I also have the groove you mentioned, where the oil seal rides on that shoulder of the yoke. I assume that's what you're talking about. I would prefer the nudge the oil seal option over the speedi-sleeve option.

Question, when you say drive the seal 20 thou deeper do you mean toward the cross joints/universal (engine), or toward the nut? I have room to go either way but I think it can only go toward the nut due to the way that first "stepped" roller bearing retainer ring is shaped (J in the boatfix manual #6 pg 3a-16.
http://www.boatfix.com/merc/Servmanl/6/6A3R3.PDF

Oh ya, second question. When I pounded out the oil seal from it's carrier it was very obvious they used some wicked tough loctite. It was very difficult to pound out and there was a ton of red around the seal and the inner part of the carrier. I don't see any mention of using loctite or even gasket compound on the oil seal. Should I use either or press it in dry?