20HP Ser# 5184040 (1979) cant get lower unit to drop

[shawpdx1]

Bought this motor. Its stuck in forward , Cant get lower unit to drop. I have removed all the bolts Including hidden, Any suggestions? could it be rusted on spline gear up at powerhead???? any help would be great ...........Thanks Ted

 

[Maxz695]

Re: 20HP Ser# 5184040 (1979) cant get lower unit to drop

use thin putty knife to get it to come a bit then a bigger item flat that won,t damage the case keep working at it.

 

[Wingedwheel]

Re: 20HP Ser# 5184040 (1979) cant get lower unit to drop

If the driveshaft is stuck in the powerhead try to spray some PB blaster into the area where they meet. You may have to turn the motor over and let it soak for a day or two, but it will come loose. Good Luck

 

[shawpdx1]

Re: 20HP Ser# 5184040 (1979) cant get lower unit to drop

Well I got it to shift into "N" I had to take throttle linkage off shaft it rides on. and throttle it down, and it went in to "N" now it wont come back far enough to go back on shaft in "N" if I put it back into gear it will move back far emough.....something is strange here, or this is a learning curve for me does not look like anyone has messed with it. the bolts are still black............Any Ideas? the throttle and trigger have smooth action when it moves ........... just wont throttle down on shaft ....guess I need to look closer If I had schematic that would help

 

[carholme]

Re: 20HP Ser# 5184040 (1979) cant get lower unit to drop

Ted;

Here is the parts listing for your s/n;

http://www.crowleymarine.com/mercury-outboard/489.cfm

These three deal with gearing and shift shafting:

GEAR HOUSING ASSEMBLY, COMPLETE (PAGE 1 OF 2)
GEAR HOUSING ASSEMBLY, COMPLETE (PAGE 2 OF 2
SHIFT CONTROL LINKAGE

These older drawings are not the best unfortunately. Here is a condensed version of a service manual. Allow several seconds for the page to load.

http://web.ebscohost.com/serrc/pdf?...b486-d36f76545cda@sessionmgr110&vid=4&hid=104

Gerry

 

[Maxz695]

Re: 20HP Ser# 5184040 (1979) cant get lower unit to drop

turn the fly wheel when shifting into gear to get it to sync. also use the leverage (Putty Knife)when turning over to apply pressure to the LU using the PB Blaster as recommended

 

[mc66]

Re: 20HP Ser# 5184040 (1979) cant get lower unit to drop

I had same problem you must drill a hole at the top of midsection to spray anything where crank meets shaft.Drill small hole enough to fit straw and hang upside down. I waited about 2 weeks before i killed it.I wound up cracking mid section because i beat it to death with wedges. Cut it off with wiz wheel.Still wouldent come off.Hung it upside down from lu after about 4 weeks of pb blaster and heat still nothing.One day passing by for mower gave it a grudge shot and it came off.Picked up midsection cheap from e-bay.I know 1976-81 are the same check crowley to match #s of years.If i remeber correctly 15 hp 18 hp and even 40 hp use same parts.Good luck i hope for you its not like mine but mine is together and runs good if you need a mid section i have an extra motor i bought for parts let me know All this trouble for an 11 dollar impeller mc66

 

[shawpdx1]

Re: 20HP Ser# 5184040 (1979) cant get lower unit to drop

Thanks Carholme, Max & mc66 will try to figure this out. something is strange here.

 

[Mi duckdown]

Re: 20HP Ser# 5184040 (1979) cant get lower unit to drop

Use lots of marvel mystery oil. when the motor is upside down. it will run down the shaft better than any other stuff.