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Lower units different

R

rhays

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"I have an 88 bayliner capri w

"I have an 88 bayliner capri with a 3.0. the lower unit locked up and I have gotten another one. When looking at the replacement, the old one has a smaller prop shaft than the original. They both say 3.0 on the sides, the original has a model number of 985268, and the rebuilt one has a model number of 986696. I don't know what year the replacement is. Will this work for this boat? thank you for any help you can give."
 
"I'm not sure of all the d

"I'm not sure of all the differences but your model # 985268 is for a 1988 3.0 and the 986696 is for a 1991 3.0 I thought only the 2.3 models had the smaller prop shaft? The gear ratio's are different as well 1988 is 1.71:1 and 1991 is 1.86:1, you may have to play around with different prop sizes to try and compensate for this."
 
"I appreciate your help. Assu

"I appreciate your help. Assuming that bigger is stronger, the new lower unit, (1991) has a bigger prop shaft and will need a different prop. the top end looks visually the same, but the bottom is about one inch larger. It looks like it will bolt right up to the back of the boat. The original prop is a 13 x 19. With the different gear ratio, will I need to go down to a 17, or higher? Thank you for your help."
 
"OK...I'm a little confuse

"OK...I'm a little confused, in your original post you said " When looking at the replacement, the old one has a smaller prop shaft than the original."

I read that as the replacement drive had a smaller propshaft but now it sounds like your original drive has a smaller shaft than the 1991? Best to count the splines on each shaft to be sure."
 
"In 1989 or 1990, OMC quit mak

"In 1989 or 1990, OMC quit making the 13 spline Cobra lowers, and started using the larger 800 size lower units on 3.0 setups. Same ratios, but heavy duty. You'll need to find a 15 spline prop of the same pitch as your old 13 spline prop, and get used to putting more gear lube in your new lower. "
 
"I guess that I was thinking f

"I guess that I was thinking faster than I can type, and not typing what I was thinking. the orginal is the 13 spline from 1988, and the replacement is the 15 spline, a 1991. Getting the new unit on has proved impossible by myself. the boat rep stated to get two people and keep trying,,,,
thank you for all your help. This forum has been invaluable to me as I have learned more in the last week reading, than a manual could ever teach me in a year."
 
sometimes the bellows swell up

sometimes the bellows swell up.... get a long smooth screwdriver through the u-joint - 1 person crank the ujoint back and forth and both push.... I use Caterpillar hydraulic oil additive Cat part # 1U9891 on the bellows - slides right in...
 
Get an engine alignment tool a

Get an engine alignment tool and check. Drive should slide in without problem if engine is properly aligned.
 
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