merc 40 shifting prob

[boatsinker]

i recently bought a 14 alu. boat from a "friend".The motor will not shift into reverse.I droped the lower unit and i can turn the shift spline and it easily will go into forward or reverse.i have the remote control removed from the motor and all linkage on the powerhead works freely. bolt the lower unit back up and push the shift linkage it will not engage reverse unless you hold hard pressure on the shift linkage.when i let go it pushes back to between neutral and reverse. 1980 40hp merc 2-cyl.need help wife wants to go fishing.appreciate any help!!!!the guy i bought the boat from changed impeller before i bought it and hadnt used it since.reverse worked fine the last time he used it.

 

[CAPTBLACKSMARINE]

Re: merc 40 shifting prob

BOATSINKER, I HAVE SEEN MANY TIMES WHERE A CUSTOMER REPLACED HIS OWN IMPELLER AND THEN HIS MOTOR WOULD NO LONGER SHIFT PROPERLY.MOST OF THE TIME WHAT HAD HAPPENED WAS THEY MIS ALIGNED THE SHIFT SHAFT ON THE LOWER UNIT AND THE ONE ON THE MOTOR IT IS A SPLINED SHAFT AND CAN GO ON IN DIFFERENT POSITIONS.TO CORRECT IT YOU NEED TO SYNCHRONIZE THE TWO.PUT THE SHIFTER ON THE CONTROL BOX IN FORWARD THEN TURN THE SHIFT SHAFT ON THE LOWER UNIT UNTIL IN POSITIVE FORWARD ,(YES IT WILL GO INTO FORWARD IN MORE THAN ONE POSITION)THE BEST WAY I CAN DESCRIBE HOW TO KNOW WHICH ONE IS WHICH IS TO LOOK UP AT THE SHIFT SHAFT ON THE MOTOR AND HAVE SOME ONE MOVE THE HANDLE SO YOU CAN TELL WHICH WAY IT TURNS THE SHAFT TO GO FROM FORWARD TO NEUTRAL AND THEN REVERSE. AND PUT THE ONE ON THE LOWER UNIT SO IT FOLLOWS THE SAME PATTERN.WHEN IT IS RIGHT IF YOU TURN THE SHAFT ON THE LOWER ONE CLICK IT WILL BE IN NEUTRAL AND ONE MORE IT WILL BE IN REVERSE BUT BE SURE TO PUT IT AND THE HANDLE BACK IN FORWARD BEFORE TRYING TO INSTALL IT . ALSO A GOOD TIP IS TO HAVE A PAIR OF NEEDLE NOSE PLIERS HANDY SO YOU CAN REACH IN AND MANEUVER THE SHAFT TO HELP IT LINE UP WITH THE ONE ON THE LOWER UNIT. GOOD LUCK . OUNCE YOU GET IT OUT OF POSITION IT CAN BE A PAIN FOR SOMEONE THAT IS A NOVICE TO GET IT BACK IN THE RIGHT SPOT.

 

[boatsinker]

Re: merc 40 shifting prob

thanks captblack.everything appears to be correctly alined.After checking more into my problem it appears my lower unit has a problem. It is very resistant to shift into reverse from the shift spline on the lower unit;SOMETIMES.Other times it will go in gear easily.Any advice from you or anyone would be greatly appreciated!!! Also turning the prop doesn't seem to help either way. Its resistant sometimes.

 

[trevorcday]

Re: merc 40 shifting prob

Your lower unit is spring loaded to go into forward so you are working against the spring when you go into reverse. This is a sort of failsafe measure I guess. If you are only going to have one gear best to have forward. Often the problem of no reverse is caused by wear in the shift cam and follower in the lower unit combined with wear on the teeth of the shift clutch and reverse gear. The lower unit requires special tools to disassemble so you will probably need to have a dealer do it for you. If you have them inspect these parts you may find the problem. If you can get away wothout changing the rev gear it won't be too expensive, but if the rev gear is worn in the area that the shift clutch engages you will need to replace it.

 

[boatsinker]

Re: merc 40 shifting prob

thanks mr merc!! I think i have found a local outboard guru that will look at it no charge. He has a good reputation with the many people who have refered me to him. I will be ,as always , cautious before paying for anything major. I still wish i knew why the lower unit will go into reverse fine sometimes and then kick back like a mule others. All of you guys are awesome and i appreciate all of your help.