Gen 1 Alpha 2 Leaking Oil

[BinLinerCashity]

1997 3.0 with then G1A2 is leaking oil from the weep hole above the shift shaft. had it on the water yesterday and came home from work to the leak. i’m a technician at a dealership so i figure i can fix it myself but would like some guidance. what’s needed for this repair and what might be leaking up there?

 

[Bt Doctur]

up that high is the input shaft seal. If you pull the drive you will find oil in the bellow

 

[BinLinerCashity]

up that high is the input shaft seal. If you pull the drive you will find oil in the bellow

any chance you could drop a part# or a diagram? i’m a little lost here, i’ve worked on plenty of boat engine but never any drives.

 

[BinLinerCashity]

up that high is the input shaft seal. If you pull the drive you will find oil in the bellow

can i replace the seal by just pulling the whole drive off at the gimbal or do i have to split the drive

 

[kghost]

First, Its is a Alpha 1 Gen II

Second, How mechanically inclined are you and do you have ANY Mercruiser special tools need to work on an outdrive?

first step is to drain outdrive of gear oil.
Next remove drive from boat- best to have a stand of some kind to support the drive when off the boat
Next pressure test to about 15 psi to find any leaks.

If what BT doctor said is true, below is a parts diagram of the upper gear case showing the parts.

Items 16 (Oring) 17 & 18 are the carrier ring and seal [item 18 -This is what may be the issue] Typically 17 & 18 come pre-assembled or you can purchase the seal itself and press old one out and press new one in to seal carrier ring.

Now to get that bearing/seal assembly out of the housing you need a special tool to remove the large housing nut and a service manual to reassemble and torque the shaft nut to specification (requires a analogue (round gauge type) Inch/lbs torque wrench and able to do a rolling torque set up.

First step though is to pressure check entire outdrive to identify the leak. This has to be repeated after first leak is fixed and drive is reassembled to confirm no additional leaks.

 

[Dieter]

any chance you could drop a part# or a diagram? i’m a little lost here, i’ve worked on plenty of boat engine but never any drives.

BT and Ghost have you on the right path but get the factory manual (#14) as it has all the procedures special merc tools to do it right the first time.

Start by taking the drive off and pressure testing it to see where it is leaking. As mentioned likely bellows will have oil in them.

While the merc specific tools can get pricey I have found them used on ebay for about half price. If you are a decent tech at a dealer you will have no issue with the factory manual and tools.

I did my 2003 gen 2 two winters ago because I snagged a fishing line on prop shaft, only seal on it that was bad ish was the shift shaft. I replaced them all because then I should be good for as long as I'll own the boat. OEM parts are best. the bearings if bad you can get the numbers off and buy from a bearing house.

 

[BinLinerCashity]

First, Its is a Alpha 1 Gen II

Second, How mechanically inclined are you and do you have ANY Mercruiser special tools need to work on an outdrive?

first step is to drain outdrive of gear oil.
Next remove drive from boat- best to have a stand of some kind to support the drive when off the boat
Next pressure test to about 15 psi to find any leaks.

If what BT doctor said is true, below is a parts diagram of the upper gear case showing the parts.

Items 16 (Oring) 17 & 18 are the carrier ring and seal [item 18 -This is what may be the issue] Typically 17 & 18 come pre-assembled or you can purchase the seal itself and press old one out and press new one in to seal carrier ring.

Now to get that bearing/seal assembly out of the housing you need a special tool to remove the large housing nut and a service manual to reassemble and torque the shaft nut to specification (requires a analogue (round gauge type) Inch/lbs torque wrench and able to do a rolling torque set up.

First step though is to pressure check entire outdrive to identify the leak. This has to be repeated after first leak is fixed and drive is reassembled to confirm no additional leaks.

View attachment 35934

pressure tested top unit and it holds only about 8 psi then begins to have a trickle of gear oil out of that weep hole above the shift linkage. oil in both units looks clean no milkshake thankfully. anyway you could link those special tools needed to disassemble the upper unit? will i be able to replace the needed seals without separating the halves? if i need to separate them i figure ill replace the impeller as well while im in there boat just hit 250hrs. and when you say press the seal out will i be able to by hand or is a press and or puller required?

 

[BinLinerCashity]

BT and Ghost have you on the right path but get the factory manual (#14) as it has all the procedures special merc tools to do it right the first time.

Start by taking the drive off and pressure testing it to see where it is leaking. As mentioned likely bellows will have oil in them.

While the merc specific tools can get pricey I have found them used on ebay for about half price. If you are a decent tech at a dealer you will have no issue with the factory manual and tools.

I did my 2003 gen 2 two winters ago because I snagged a fishing line on prop shaft, only seal on it that was bad ish was the shift shaft. I replaced them all because then I should be good for as long as I'll own the boat. OEM parts are best. the bearings if bad you can get the numbers off and buy from a bearing house.

is it necessary to buy the mercruiser torque wrench? i have swivels and spent 1000 bucks on a snap on torque wrench lol.

 

[kghost]

Did you drain gear oil before pressure checking? It has to be done that way.
A drive will produce around 6-9 psi when in operation. You must go above that to
Propperly check for bad seals.
Merc has no specification for testing but OMC did and theres was 17 psi.
I use 14-15 psi and have been for a very long time.

Drive MUST be off when pressure checking also so you can see/hear leak area. especially if it is the upper carrier seal.......as BT said, bellows may have gear oil in it from seal leak if its that one thats leaking but you wont know unless you follow my advice. You must confirm source of leak before tearing into drive.

Dieter can send you the tool info.

 

[kghost]

is it necessary to buy the mercruiser torque wrench? i have swivels and spent 1000 bucks on a snap on torque wrench lol.

No
But it must be analouge. Dial type and the rolling torque range is 6-10 inch/lbs so it needs to capable of that range

 

[Dieter]

is it necessary to buy the mercruiser torque wrench? i have swivels and spent 1000 bucks on a snap on torque wrench lol.

no just needs to be the kind for rolling torque. I have used both the dial type and a low range beam style for rolling torque on both this and doing ring and pinion replacements.

look the tool numbers up on ebay for used ones. I think a lot of guys like us buy the tools to do a repair and sell them when they move on from the boat.

you will need the tool to remove the retaining ring for the input shaft seal. if yoke is worn you will need to use a speedi sleeve or replace.

you will need to split the drive for the water pump, you can test the lower alone by clamping over the oil passage , to test the upper you need a spare drive shaft. I ended up buy a used one to set rolling torque after replacing upper bearings. Mine were pitted from it sitting before i bought it

 

[kghost]

As far as seprating upper from lower.

Until you are 100% sure where the leak is there is no answer.

If it turns out to be the carrier seal, then No, you dont need to split housings.

Also without the manaual you will not have any other specifications for torque of other fastners and the best way to rwaasemble bearing pack (4 beaeings back to back)

Also note: if its the seal being diacussed, when reassembling and tightening shaft nut for rolling torgue, I reccomend RED loctite on male and female threads

 

[kghost]

no just needs to be the kind for rolling torque. I have used both the dial type and a low range beam style for rolling torque on both this and doing ring and pinion replacements.

look the tool numbers up on ebay for used ones. I think a lot of guys like us buy the tools to do a repair and sell them when they move on from the boat.

you will need the tool to remove the retaining ring for the input shaft seal. if yoke is worn you will need to use a speedi sleeve or replace.

you will need to split the drive for the water pump, you can test the lower alone by clamping over the oil passage , to test the upper you need a spare drive shaft. I ended up buy a used one to set rolling torque after replacing upper bearings. Mine were pitted from it sitting before i bought it

The correct torque wrench would be a 0-15 inch/pound dial type. Click is not reccommended.

I have a 0-15 inch/lb CDI #151LDN with certificate. 1/4 inch drive.

 

[kghost]

It appears my model is now NLA.
Here is a pic

Others including Snap on have similar do a google search

 

[Bt Doctur]

locate a service manual FIRST and understand how the system works before turning a wrench.
Basically you unscrew the retainer (its captive) , pull the shaft straight out, remove bearing package, R & R the seal ,replace gear and bearings, torque to spec with used bearings, reinsert shaft and tighten and torque to spec (200ft/lbs)

 

[kghost]

locate a service manual FIRST and understand how the system works before turning a wrench.
Basically you unscrew the retainer (its captive) , pull the shaft straight out, remove bearing package, R & R the seal ,replace gear and bearings, torque to spec with used bearings, reinsert shaft and tighten and torque to spec (200ft/lbs)

That spec is wrong, Its a different value with a specific length torque wrench and the tool for the large retainer nut. 18 inch torque wrench as shown in manual with wrench make the setting on torque wrench 123lb/ft. Which if only using a torque wrench it would be 200#. But with the added wrench to the torque wrench it becomes a torque multipier....thus the lower setting on torque wrench.

The shaft nut is completely different. (Rolling torque)

 

[kghost]

Below are two images.
1. Wrench needed for retainer nut if you have a upper carrier seal leak
2. The seal and carrier as an assembly (purchased this way from Merc if you choose and if needed) other wise you can buy the seal alone.

 

[kghost]

That spec is wrong, Its a different value with a specific length torque wrench and the tool for the large retainer nut. 18 inch torque wrench as shown in manual with wrench make the setting on torque wrench 123lb/ft. Which if only using a torque wrench it would be 200#. But with the added wrench to the torque wrench it becomes a torque multipier....thus the lower setting on torque wrench.

The shaft nut is completely different. (Rolling torque)

 

[BinLinerCashity]

As far as seprating upper from lower.

Until you are 100% sure where the leak is there is no answer.

If it turns out to be the carrier seal, then No, you dont need to split housings.

Also without the manaual you will not have any other specifications for torque of other fastners and the best way to rwaasemble bearing pack (4 beaeings back to back)

Also note: if its the seal being diacussed, when reassembling and tightening shaft nut for rolling torgue, I reccomend RED loctite on male and female threads

okay so one more newby question for you gentlemen before i get my hands dirty. if my bellows are dry is there a chance it could be the oil seals on the downward shaft leaking and weeping from the hole? i believe they are seals #5 on the diagram.and if it were those two seals would i be able to reinstall the drive shaft without replacing the input shaft seals or would you recommend replacement after removal anyways. i know a guy at a marine shop out here who i can just drop the shaft off to to be replaced and torqued properly so i dont f#ck anything up.

 

[Roadking57]

BinLinerCashity, There are some videos you can watch that will help you understand whats involved. Look up DIY with Michael Borders stern drive.
He has a series on a Alpha One Gen I (I think its a gen 1). Remember its for reference ONLY and make sure you use the manual procedures called out for your particular model if you choose to DIY. Some here dislike videos but for newbies it gives you an idea of whats all involved and then you can make a decision if its something you can/want to tackle or not.

Good Luck Sir.

 

[Dieter]

The correct torque wrench would be a 0-15 inch/pound dial type. Click is not reccommended.

I have a 0-15 inch/lb CDI #151LDN with certificate. 1/4 inch drive.

I wasn't saying to use a click. I was saying my beam style low range in lb reads just as accurate as my more expensive dial type with cert and cost $57... Used this for both ring and pinion work and the drive. When I did the drive work I bucked up for a dial style and compared the readings between them. For a pro get the dial type but for shade tree work the beam style is ok in my experince.

okay so one more newby question for you gentlemen before i get my hands dirty. if my bellows are dry is there a chance it could be the oil seals on the downward shaft leaking and weeping from the hole? i believe they are seals #5 on the diagram.and if it were those two seals would i be able to reinstall the drive shaft without replacing the input shaft seals or would you recommend replacement after removal anyways. i know a guy at a marine shop out here who i can just drop the shaft off to to be replaced and torqued properly so i dont f#ck anything up.

on a gen 2 for seal % you have to remove the lower drive shaft bearing cup. Small slide hammer will get it out. just keep track of the shims as they set gear height if I recall correctly. if bearings are not replaced in theory put same shims in and should be ok.