View Full Version : 1990 Chrysler Force 150

08-28-2008, 11:21 PM
"I have a 1990 Chrysler Force 150 that I'm trying to tear down the lower unit to repair/rebuild it.

I have successfully removed the propeller shaft.

However, I am not able to get the motor shaft out of the housing. I have taken out the upper taper bearing raceway, carefully removed and saved the shims. Removed the nut on the bottom of the shaft.

Can someone tell me if the shaft is supposed to pull out with the gear in place or if the gear has to come off before the shaft will come out.

Also, if anyone knows if any special tools are required. (I can make almost anything) or if there any tip or tricks that would help.


08-30-2008, 08:10 AM
"If you are talking about the pinion gear connected to the bottom of the driveshaft - it has to come off (inside the gearcase).

If you have the nut off that fastens the pinion onto the bottom of the driveshaft then the only other step is to get the driveshaft out.

It may seem like it is "stuck" in there. That is normal. Usually what I would do at that point is use a bench vice.

I wrap the driveshaft with a couple layers of rags and clamp it in the vice. Then use a block of wood and a mallet to tap the lower unit case "off" of the driveshaft.

Just be careful (a helper is good to be the "backcatcher"). It's only aluminum, and make sure it doesn't hit the floor when it pops loose (never happened to me) "

08-30-2008, 08:11 AM
"PS - if it's a 1990, it will be a "Mercury" Force. Merc owned them from 1986 on...."

Ken Kolbly
08-30-2008, 12:52 PM
"I have the nut off the pinion and I can "rattle" the shaft just a little, but the pinion seems stuck to the shaft.

I'll try what you suggest.

Last time we had the boat out (2 years ago) we were caught in a severe thunderstorm while camped by the shore and we suspect that was when a hole got punched in the side of the lower unit by the shift rod, letting water in the gear housing, so there is a quantity of rust present.

That is why I'm tearing it down, to determine if it can economicly restored to full service.

Would it be appropiate to ask here, or should I start a new thread, if someone knows the range of compatible lower units, in terms of year and horsepower? I am looking at several LU's on eBay.

This is all very new to me and I am learning as I go. I have ordered a shop service manual, but it won't arrive until next week.


Ken Kolbly
08-30-2008, 02:08 PM
"1) It is a 1990 Force. It is also labled with "U.S. Marine Power" I'm not sure why I refer to it as a Chyrsler, except maybe that is what somebody else said.

2) Doing what you said, I got the shaft out. Thanks for that!

Now I have only to finish taking apart the shift rod assembly and I'll have it completely torn down.

There is light rust color throughout, but nothing that won't clean up nicely, so I think we are in good shape. A good cleaning, new seals and oil should do the trick. The only spot that the rust looks bad is where the shift rod couples to the shaft, but it should clean up fine.

I hope there is a helpful trick to getting all those needles back into place, otherwise it's going to be interesting!

http://www.marineengine.com/discus/messages/12480/217942.jpgLower Unit Exploded Photo

Ken Kolbly
08-30-2008, 03:55 PM
"Got the shift linkage apart. It should have been easy but it was a booger because the pivot pin was bent. ("Pin Retainer" P/N 826374)

The "Coupling assembly" (P/N FA84621-1) seems to be badly damaged, probably by some yo-yo using all available force to shift it. I just can't imagine the strength required to bend those ears back like that. Maybe the damage built up over time.
http://www.marineengine.com/discus/messages/12480/217949.jpgDamaged Coupling Assy"">

Google has not helped me find a supplier. Seems to be a "No Longer Available" item. I can make this part if I need to, but I'd rather buy it somewhere. Any suggestions?

Thanks in advance."

Ken Kolbly
09-15-2008, 01:02 AM
"I just thought I would share the fact that I was unable to come up with another shift "Coupling Assembly" either through regular parts houses or marine junkyards. I'm sure there are some out there somewhere but I did not find one.
Therefore, I went into my machine shop and spent 6 hours today making one. At my hourly rate, that makes this a $450 part!

It looks good, but will it work?
http://www.marineengine.com/discus/messages/12480/219026.jpgNew Shift Coupler

11-19-2008, 08:01 PM
Nice work!!