Gear oil escaping via cavity drain hole on Alpha Gen i sterndrive

[Jorma]

Hi,

I have just installed my alpha gen 1 leg for the 100th time. When i fill with gear oil it escapes via the drain hole in the lower unit. I have installed a new water pump and oil gasket. Can someone please assist?

 

[smokeonthewater]

That is the drain hole for the exhaust cavity.

You have a bad seal OR a cracked housing...
My bet is a seal... Probably the upper driveshaft seal... There is also a lower seal under the water pump...

 

[Jorma]

Hi,

Can you explain to me where the seal is on the upper driveshaft?
By the base do you mean the O ring on the base itself? I have installed a new base yesterday... could that o Ring move during installation?

 

[Jorma]

Found the schematic for the oil seals in the upper casing... thanks.
The leak only happened after i installed the new water pump base.... is it possible the oil ring on the base moved while i was pressing the base into place?

 

[oldjeep]

Found the schematic for the oil seals in the upper casing... thanks.
The leak only happened after i installed the new water pump base.... is it possible the oil ring on the base moved while i was pressing the base into place?

If you are talking about the quad seal then yes, that little can fall off when installing. I stick it in place with a dab of petroleum jelly so it doesn't want to move as easy.

 

[Jorma]

Sorry, i mean the o ring which is installed at the bottom of the water pump base.... it was very difficult to get the base to position and i had to tap it into place... just wondering if the o ring could have moved and caused the oil to escape...? Item 23...

 

[Jorma]

The o ring which fits onto the water pump base assembly....item 24.

 

[smokeonthewater]

No... I believe the seal is 25 and or 26....

I still suspect you tore up the upper seal tho

If you have the whole drive off when you fill it you can look in the exhaust port from the boat side of the upper and see if oil is running down the shaft.

 

[Bondo]

Ayuh,.... My guess is it's the shift shaft seal,....

I'll move this to the Mercruiser forum,....

 

[Jorma]

I had the leg on when i filled with oil but when i split it there was no oil over the top cover of the water pump... if the oil ran down the shaft surely you would see evidence of it on the water pump??? If its not a big job i would replace the upper housing seals as well.... To do the job correctly i would then need 4 seals? Correct? 2 for upper and 2 for lower?

 

[Jorma]

Hi Bondo.... how do i go there? First time i used this forum.....;-(

 

[Jorma]

Got it.....

 

[PETCH]

I've got the same issue posted in another thread: http://forums.iboats.com/forum/eng...004-alpha-one-gen-one-upper-drive-shaft-seal
You can read Ziggy's response. I'm also replacing the Impeller housing both top and base, and the shift shaft seal. I just bought Part#14 in the drawing- the lower drive shaft seal Mercruiser # 26-96503-1. I'm waiting on a couple more items, but plan on getting all this done by end of weekend. I'll update then......
Another link on the topic: http://sterndrive.cc/vbforum/showthread.php?1209-Upper-Drive-Oil-Seal
good luck!

 

[Bt Doctur]

. it was very difficult to get the base to position and i had to tap it into place

Then you have something wrong. The base locates on the 3 studs so it6s impossible to get that wrong. the only other thing is you used the wrong base .
Did you examine the old base to make sure it matched up?
The gasket goes on the base and then the O ring goes on the base

 

[achris]

Oil from that hole could come from the following.

Top seal on the upper drive shaft in the drive shaft housing. Very unlikely. The seal and shaft are not moved or disturbed in any way during servicing..
Shift shaft seal. Possible, but I would think only about a 10-15% probability.
Missing/displaced quad ring seal (between the 2 housings). This would be my bet.

If it were the seals in the water pump base, you'd see the oil at the water intakes at the same time (and more there than the forward cavity drain hole).

Chris..

 

[Jorma]

So got the leg of again. It appears that the oil seal in the water pump base, item 26 was installed upside down. This is straight from the manufacturers / suppliers so it is worth checking EVERYTHING before installation. Would the upside down seal be the reason i have a gear oil leak into the cavity drain hole? No oil running down the shaft so we can eliminate the upper seals, although i have replaced the lower one as a precaution.

 

[Bt Doctur]

even if it was installed upside down oil would not pour out like that, there is an oil seal and a shaft seal. can you post the part number of the water pump kit

 

[Jorma]

[h=1]SEARCH RESULTS FOR 'RM46-01844'[/h]

1 Item(s)
Show 50 100 All per page
​

View as: Grid List
Sort By Relevance Name Price Returns Accepted Return policy details Return postage will be paid by Type

• [h=2]Water Pump Base for Mercruiser MR, Alpha Gen 1[/h]
  Excl. Tax: ?16.00Incl. Tax: ?19.20​
  [COLOR=white !important]ADD TO CAR

[/COLOR]

 

[Bt Doctur]

does your driveshaft have a spring loaded pin on top? When you removed the old base ,did you see the bearing locknut?

 

[Eric 3.7LX Alpha 1]

No preload pin on left, preload pin on right, they use different water pump bases.