Dfi oil leak at lower unit seam with midsection

[greauxpete]

Serial number in signature.

I noticed dfi oil leaking between the lower unit
and midsection. Based on searching the forum, it looks like this is more than likely a lower crank seal leak.

I have reviewed the power head removal procedure in the FSM, it looks straight forward and I have access to a facility to remove the power head (overhead crane). Are there any pitfalls I need to look out for? Any service items I should consider while I have the power head off?

Thanks fellas.

Steve

[RangerJim]

make sure you dont have a leaking oil pump before you pull the powerhead

[greauxpete]

I found this leak under the cowl,
but not sure how this leak gets
to the lower unit/mid section seam..
Oil pump looks dry to me.

20190909_144331.jpg

[EuropeanAM]

Powerhead gasket, two lower crank seals, o-ring for carrier, lifting eye, engine lift, torque wrench with torque-adapter, and basic hand tools are what you'll need.

Might take a look at the strainer in the tuner (and at the idle relief ports) - if these need attention, pull the adapter plate too while you're in there.

[greauxpete]

Thanks Don, didn't think about the torque adapter. It does look pretty tight for torque wrench access.

I appreciate your help.

Steve

[Savage]

Definitely need a torque adapter so you dont warp #6 cylinder.

[greauxpete]

Savage, I assume your referring to torquing the power head back to the exhaust player in stages (1/3 of max torque, 2/3, then max preload torque) to prevent cocking and damage to #6.
I didnt see a torquing pattern in the FSM for the 10 bolts.

If not, please expand.

Thanks again,

Steve

[Savage]

Click on this >>>>Manual error powerhead nuts ?

[greauxpete]

My FSM (P/N: 90-859769R2) states:
Install 10 flat washers and 10 locknuts which secure powerhead to exhaust extension
plate/driveshaft housing. Torque locknuts in 3 progressive steps until secured.

Torque nuts to 50 ft*lbs.

Comments/Questions:
1.The 10 bolts are not numbered in my manual.
2. Where are bolts 9 and 10 located?
(Back of motor/Front of motor?)
3. It is my understanding there is an error in the FSM and bolts 9 and 10 shall not to be torqued to the full 50 ft*lbs as per Don's instruction in the above link posted by Savage.
4. The link Savage posted appears to be for as ProXS.
I have a regular Optimax. Just wanted to clarify.

Thanks guys.

Steve

[Savage]

None of the 10 NUTS get torqued to 50 lb/ft
#9 and #10 are two of the port side fasteners. You really need the get a Genuine Mercury Marine Service Manual. There is a specific pattern that the fasteners must be torqued in.

[greauxpete]

I do have a genuine fsm (hard copy)
for my serial number/year:.

It says: torque nuts to 50 ft*lbs (pointing at it in pic below)
Sadly, there is no mention of a torquing pattern or bolt labeling in the assembly instructions/procedure:
Am I missing something?
I'm really confused now..

See excerpt below, I took a picture of it:
Note: bottom right, year and manual part number.

20190910_210928.jpg

[Savage]

I believe the information in your manual was possibly published before Mercury knew they had issues with cylinder wall distortion due to the torque of the powerhead nuts. I would follow the torque instructions for a newer ProXS.

[Savage]

Here you go....20190911_172302.jpg

[JOE54]

DATS IT

[greauxpete]

Savage...THANK YOU!
Much appreciated.
Probably would have ruined my block..

Also, Don, thanks for the supplemental advice.

Steve

[Savage]

[greauxpete]

After wiping down the motor with lower cowls off and running on the muffs for 30 minutes and looking for leaks inside the cowl:

1. The lower crank seal is leaking slowly - see pic.
2. Oil pump is not leaking
3. Air handler gasket is not leaking
4. Slight drop was present on the oil filter coming off of compresser, but after wiping it, dusting with gold bond foot powder and running 30 minutes no leak.

Time to pull the powerhead and may change out hose and filter before I go to dealer to oil prime with ddt (no break in reset).

This is looking from under the forward port side of the motor and the lower crank seal housing:

20190915_120704.jpg

[greauxpete]

Can the idle relief ports be cleaned
(Drilled) without removing the tuner?

What is typically used to clean them?

Thanks

Steve

[Savage]

Tuner must be removed. Drill out the carbon if totally plugged.

[greauxpete]

Got her done..
Thanks everyone for all the help!
Especially Savage and Don.

Here are some pics:

IMG_2632.jpg

IMG_20150503_100952878_zpsvdriq0sq.jpg