1989 125HP Shim Upper bearing

[P7113t@aol.com]

I have to replace a damaged upper bearing and short drive shaft of a 2 piece drive shaft on my Force 125.

I have the following questions:

1. Can I reuse the shims (3) as a set. I will not have to replace the pinion as it appears ok.

2. The Clymer book I have references 1990 and above shim information and the table for shim installation the markings on the lower unit housing do not agree with the 1989 model I have. Am I missing something in my interpertation of the book?

3. I would like to pressure test the lower unit after I replace the bearing, shaft and seals. Is there an air fitting available or will I have to fabricate one for the vent hole.

If you have any information on my questions I would appreciate your input. Also if you have any other suggestions for me on this repair, they also would be helpful.

Thanks in advance for your help and effort.

Paul

 

[Frank Acampora]

Re: 1989 125HP Shim Upper bearing

You MUST reuse the shims because shims for that bearing are no longer available--at least, not around here. Not even from the bearing supplier. So either re-use or make your own new ones. If you find a dealer who carries some, let me know.

 

[P7113t@aol.com]

Re: 1989 125HP Shim Upper bearing

Frank,

Thanks for your reply. I have followed and respect your opinions on Force lower units.Can I place the shims as I took them out and feel comfortable that the measurements are the same.

Paul

 

[Frank Acampora]

Re: 1989 125HP Shim Upper bearing

Yes, as long as they don't show damage like cuts and wrinkles. They sit against the case with the narrow side of the outer race against them. They will show some degree of bending but that will not change the dimensions. They space the race UPWARDS because the teeth cut into those gears tend to LIFT the pinion when the engine is running. That allows correct mesh and backlash while the engine is running. While the gears are robust and Merc did improve the water pump, I don't particularly care for the design of the pinion/drive shaft bearings in that lower unit.

My lower has three shims totalling .011 and one of them is not usable, so that particular unit has been sitting in my garage (since I bought it) until I can make a brass shim.

 

[P7113t@aol.com]

Re: 1989 125HP Shim Upper bearing

Thanks for the response. By using the existing shims and not having to deal with feeler gauges makes the chore easier. I was able to fabricate an air adapter to test the LU pressure. Hopefully I will be doing the work tomorrow and will probably have additional questions.

 

[P7113t@aol.com]

Re: 1989 125HP Shim Upper bearing

I have put my 125hp lower unit back together and it shifts properly when I do it on the bench. In order to move the shaft I have to use a pipe wrench on the drive shaft. it does not move by hand. I have not added the oil yet and wounder if this is normal. It just appears to be binding in the carrier bearing area. Any comments?

 

[Frank Acampora]

Re: 1989 125HP Shim Upper bearing

Your writing that you need a pipe wrench makes it sound as if the drive shaft is really tight. Is the water pump installed? With the water pump and impeller installed, it may be too difficult to turn the drive shaft by hand, even though it is not binding.

To test, put on the prop and turn it by hand with the lower unit in gear. You should be able to turn the prop and the drive shaft with some degree of resistance, but it should turn. If it is too difficult to do by hand, then yes, something is binding.

 

[jerryjerry05]

Re: 1989 125HP Shim Upper bearing

If you haven't removed the bearing yet.It's a good bet the bearing is seizing and making it difficult to turn.
I recently bought a boat with twin 88/85 and one of the motor would just barley turn. Seems it was full of water and the bearings seized.
I'm glad I had a replacement.J

 

[P7113t@aol.com]

Re: 1989 125HP Shim Upper bearing

Thanks both of you for the quick response. I have placed a prop on it and I can turn it with effort. My next test will be to remove the water pump .

As a side note, Frank, I have found a site that has upper bearing shims for sale. I will send it to you in the near future.

 

[P7113t@aol.com]

Re: 1989 125HP Shim Upper bearing

The problem with the tight propeller shaft turned out to be the impeller and over tighting of the carrier bearing bolts. I have tested under pressure and it is leak proof at this time and the shaft now turns by hand.

Frank,

Listed below is a site that advertises upper bearing shims for a Force 125. Hope this will work for you. http://www.dougrussell.com/partscat...2,8,4,11,24,26,23,25,22,2,7,13,21,19,18,17,14

Paul (Borresens)

 

[P7113t@aol.com]

Re: 1989 125HP Shim Upper bearing

The puzzle contiues.

About a month ago I bought a used lower unit from an 85hp Force 1989, as mine had gone south. Since then I have rebuilt the original with new seals and things and have pressure tested it to be great.

The used one I bought which is Identical to my original was boat tested about 2 weeks ago and it ran fine. I did notice the new oil I had placed in it was a little milkey, however still full. Because I had just rebuilt my original and was familiar with the pressure test, I figured I might as well test the used one because the oil was milkey.

I put it under pressure and to my surprise oil started coming out of several holes beneath the long housing plate. (The one the trim tab is mounted on). I checked under the plate and observed 5 -1/8 inch holes on one side and 4 on the other side underneath the plate. The oil was coming from the 2 holes on each side in the front. The holes appeared to be drilled symetrical.

]My question is should they be there and or do you think I can plug them up.

 

[pnwboat]

Re: 1989 125HP Shim Upper bearing

Sounds like you have a bad seal. Gear oil should not be seeping out from anywhere. Typically those holes are there to drain out any residual water that gets trapped. Bad thing if you plug them up and live in an area where temperatures drop below freezing.