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1973 7.5hp Merc O.B. Lower Unit

K

KSB

New member
Hi, New to site.
Serial # on motor..3488479
Replacing all the seals and o rings in lower gear unit. There is a "carrier Assembly" part # 30541T 1 that needs to be removed in order to access one of the o rings. Can someone tell me if this part gets screwed in? I viewed the new part "on line" and it does not appear to have threads. I believe it does. Anyway, I am trying to avoid additional problems during removal. Thank you in advance for your help.
 
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The drive shaft seal is in the WP housing that can be pried out with 2 screw drivers. The prop shaft seal requires unscrewing the big nut (LEFT hand threads) and pulling the assembly out.

Having worked on a zillion of these, I recommend replacing the WP seal and see if that does it. They tend to leak here.

Jeff
 
The bearing carrier itself is NOT threaded.-------------It pulls out once the nut is out.----That bearing carrier is big $$ so carefull when you pull it out.---------The nut should have instructions on it to tell you which way it turns to come out.
 
I should have mentioned that i already had the large nut off with the shim washer below. I had to make a custom tool to get that off. The carrier is the next part to come off. There is very minimal tolerance around the carrier and the threaded side wall of the housing which is what lead me to believe it was threaded on. I have been soaking it regularly with pb blaster for the last week and also have applied heat. I tried to unscrew it and also tried to pull it out. I haven't used great force as yes this is an expensive part. The O ring below is one of the areas that failed my initial pressure test. I will be replacing all of the seals and o rings. Is it possible to twist the carrier to break it free or is there a slot or groove that will prevent twisting? I appreciate everyone's input.
 
I got it out! I still cant believe that the carrier wasn't threaded in. I would have bet money on that. I fabricated another tool and was able to use my impact wrench to get it to break free and spin back and forth. I was then able to use a make do gear puller to pull it out. the trick with drilling out the seal and using a screw worked great! i hope the hard part is over! I should be able to slip the new o ring without taking the thrust washer-shim assembly apart. If I can figure out how to post some pictures on the forum, i will share the tools i made. Everyone thank you so much for your quick response and advise!
 
For future reference, you can use the prop and some plywood as a puller. Slip the plywood pieces between the prop and the housing and use the prop nut to pull the shaft out! Works slick.

Jeff
 
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