Mercury 1990 100hp Lower unit HELP!

areg@plus12.com

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I have a 1990 Mercury 100hp... the Lower unit seized cause fishing line got in my seal! no oil..the driveshaft still turns the bearrings are all toast so have it opened.. taken the prop shaft out and bearrings but I cannot get the DRIVESHAFT removed ..the nut at the bottom has been removed the pinnion gear is still on.... how do i remove the driveshaft.. it just wont pull out the top of the lower unit... the instructions in the SELOC online manual seem to just say pull shaft out??? confused? should i hammer and apply force..??

these are the instructions.....!

22. Select a box end wrench the same size as the pinion nut. This tool will be used to prevent the nut from turning as the driveshaft is rotated. Obtain a Driveshaft Holding Tool (#C-91-56775).

23. Install the holding tool onto the end of the driveshaft. Now, with the box end wrench on the pinion gear nut, use an appropriate wrench and rotate the tool and driveshaft counterclockwise until the pinion gear nut is free.

24. Remove the nut and the pinion gear assembly.
Set aside the old pinion gear nut. The manufacturer recommends the nut not be used a second time. Once the nut has been removed it loses its designed locking characteristics. The old pinion nut will be temporarily installed on the driveshaft for shimming and backlash calculations, and then removed and discarded.

25. Obtain and position a Universal Puller Plate (#C-91-37241) between the pinion gear and the tapered roller bearing. Place the puller plate and gear, with the gear on the bottom, in an arbor press. Use a suitable mandrel and press the gear free of the bearing. The mandrel must contact the gear collar, but clear the bearing cage.
Once the bearing has been removed, it cannot be used a second time. The roller cage will be distorted during the removal process.

26. Pull the driveshaft up and out of the lower unit housing.


 

Laddies

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Re: Mercury 1990 100hp Lower unit HELP!

The pinion is seated on the shaft, without a drive shaft holder you will have to place the drive shaft in a vise use cushion jaws if you have them and don't clamp on a surface that you can't clean up if you damage it next take a hardwood block and place it on the lower units upper mating surface as close to the drive shaft as possible and hit it with a 3# hammer to dislodge the pinion gear
 

areg@plus12.com

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Re: Mercury 1990 100hp Lower unit HELP!

Thanks for the reply...

can i use two pieces of hard rubber between a vise??hockey pucks ? as a cushion jaw? I knew it needed some force didint know how much... the SELOC manual doesn't explain properly..
 

Laddies

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Re: Mercury 1990 100hp Lower unit HELP!

We use a set of brass jaws but I suppose the the hard rubber should work even a couple pieces of hardwood should work, your going to have to give it a good whack with the hammer
 

areg@plus12.com

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Re: Mercury 1990 100hp Lower unit HELP!?????????

Re: Mercury 1990 100hp Lower unit HELP!?????????

Been hammering very hard in a vice!! but the thing won't budge..is there aclip or something..this thing does not want to move...!!!! If we hammer harder feels like something might break... the pinion gear feels a little looser but still in place.. what is holding the driveshaft in??????????:confused:
 

Laddies

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Re: Mercury 1990 100hp Lower unit HELP!

There are only 2 things that can be holding the shaft once the pinion nut and driveshaft cover are removed, the drive shaft bearing has turned in the case or the shaft is stuck (welded from heat) to the pinion bearing
 

areg@plus12.com

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Re: Mercury 1990 100hp Lower unit HELP!

so what is the solution.???. maybe the drive shaft bearing has turned in the case.. how can i get it out..do we just whack it even harder..will anything break? What would you do?? Any help or advise appreciated..

thanks
A.
 

Laddies

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Re: Mercury 1990 100hp Lower unit HELP!

This is probably not the answer you want but it may be the time to take it to one of the better service places in your area. They may be able to get it apart, remember at this point is junk and it may stay junk, they or you may damage it beyond repair finishing the disassembly. It's at lest worth a visit to talk with the service manager at a couple of local repair shops
 
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