New oil seal does not fit bearing carrier

[Coach 78]

I have searched the forum for information to solve my problem but have not found any. I have a 1980 Mercury 90 HP motor.
Found water in the lower unit oil so I am in the process of changing the oil seals. Doing the prop shaft seals first. Not having the tool to remove the cover nut and remove the bearing carrier, I read and watched a few videos and tried the short cut method of removing the seals. No problem. Ordered new seals using the Mercury diagram part references. The inner seal has an OD of 1.692 inches on the package. It went in just as I expected nice and snug, some gentile taps to get it in place. The outer seal is to big and will not fit inside the bearing carrier. OD of the outer seal is labeled 1.754 inches. I oiled the shaft and put silcon sealant on the bearing carrier, This seal is not going in. I have used a digital caliper to confirm the diameters. My measure of the bearing carrier inside diameter is somewhere between 1.690 and 1.700 inches
Is leaving the bearing carrier in place keeping it from flexing enough to allow the seal to fit? Am I missing something else?
Any assistance will be appreciated

 

[racerone]

Did you buy a seal kit ?-----That bigger seal is the wrong one .----You can not make it fit.

 

[harringtondav]

^^^ Yes. The seals should be the same outside dia. The rear, outside seal is usually has a metal case and shield to protect the garter spring from getting sand packed or damaged.

What is your motor's serial number? Maybe I can help find your seal.

 

[Coach 78]

I did not purchase these as a set or kit, I used the mercury diagrams to Id the parts and corresponding numbers.

The inner seal is sierra part 18-2002 replacing merc part 26-76868, it fits
The outer seal called for in the merc diagram is sierra part 18-2053 replacing merc part 26-70081.
I also have a GLM 85530 seal listed to replace merc 26-70081 also to big. As you describe, harringtondav, the outer seal has a metal band protecting the retaining wire. It looks like the removed seal just to big. The removed seals got distorted so I cannot get a measure and they have no identifying marks that I can find.


The motor serial number is 5672682,
Thanks

 

[harringtondav]

It looks like your motor is a 6 cyl. Correct? 26-70081 is what I also found for the outer shielded seal. The Sierra 18-2002 looks good. I Googled the 26-70081 (Mercury 70081) and found New Old Stock (NOS) on eBay. The pic was a shielded seal.

If all else fails you can use the 18-2002, spring outside, for the rear seal. It's life will depend on the amount of sand you churn, and the number of fishing lines you wind up on the shaft. https://public-mercurymarine.sysonl...=GuestNA_KEY=NA_KEY_VALUElangIF=englangDB=eng

 

[racerone]

Possibly a replacement lower unit.------Is there a grease fitting for the rear bearing ?

 

[harringtondav]

PS: While you're in this deep, replace the carrier O ring 29976. That should take care of any prop shaft water entry. Up above the two water entry seals are 79884 water pump oil seal and 76384 shift shaft seal. Throw in a new impeller and water pump gaskets while you're at it.

https://www.mercurymarine.com/en/us/.../parts-catalog will get you in w/o a password. 90,900. Find your s/n group.

 

[Coach 78]

Looks like I will see if he can find the correct cover nut tool and do things the right way. I hate to spend the $$$ on a rebuilt lower unit they seem pretty pricey. And I will follow your advice and do the impeller and all that goes with that.
thanks for the input.