Gears Grinding when going into reverse

Roberthill

Petty Officer 1st Class
Joined
Dec 3, 2012
Messages
317
2001 70 HP MERCURY FOUR STROKE . Grinds a little when going into forward but grinds a lot when going into reverse . This is a replacement motor bought from a outboard mechanic he says you have to slam it hard when changing gears . Don't sound right to me . Comments ?
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
39,407
Re: Gears Grinding when going into reverse

Shift with a quick firm motion.----No " granny shifting " is to be done on an outboard motor.--When you ease it into gear you will do damage !
 

oldman570

Lieutenant Commander
Joined
Mar 25, 2011
Messages
1,615
Re: Gears Grinding when going into reverse

Shift with a quick firm motion.----No " granny shifting " is to be done on an outboard motor.--When you ease it into gear you will do damage !

^1 on Raceone answer

Slow shifting of the gears eats up the clutch dog and the mating area on the gears. Replacing just those items can get VERY expensive.
JMO Oldman570
 

Roberthill

Petty Officer 1st Class
Joined
Dec 3, 2012
Messages
317
Re: Gears Grinding when going into reverse

Been using outboards for over 50 years just never had this much grinding shifting gears as with this motor . With that what I'm thinking is that previous owner or owners was "granny shifting" and caused excessive wear . Thanks to all for response .
 

carholme

Rear Admiral
Joined
Sep 4, 2010
Messages
4,845
Re: Gears Grinding when going into reverse

Robert:

You say that it is a 2001 70 hp. Could it be a 75 hp? Do you have the s/n and have you checked the LU oil for metal particles?

Gerry
 

Roberthill

Petty Officer 1st Class
Joined
Dec 3, 2012
Messages
317
Re: Gears Grinding when going into reverse

Belongs to a friend and his health is bad , motor is on a pontoon and it doesn't come out of the water(hard to work on). It could be a 75 hp . Have not ckd lu oil .
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
39,407
Re: Gears Grinding when going into reverse

Forward and reverse gears are both turning at about 400 RPM when engine is idling.----The metal clutch dog slides into the gears to engage and drive the propshaft.---Engaging gears quickly does the least amount of damage !!
 
Top