85 Mercruiser, 170 i/o 224: Won't go into fwd/rvs, overheating.

Golflover

Seaman
Joined
Sep 10, 2009
Messages
51
Hi Forum,

I have a 85 Sea Ray Seville with a 170 HP 224 3.7L i/o which I love. The short: I boated to my destination yesterday and sat for 6 hours. When it was time to leave it started right up but when I went to put it in fwd in would not engage and neither would Rvs. I also noticed the temp was elavating quickly for running for a short period of time. I did not notice anything unusual in terms of noise. It appears that the shifter cable is operating. Since it appears the impeller is not working in conjunction with the failure to engage, is this most likely a coupler issue or tell tale of another problem or is it possible there are several issues here?

Thank you for any guidance you may have to offer.

Kurt:(
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
Re: 85 Mercruiser, 170 i/o 224: Won't go into fwd/rvs, overheating.

coupler or lower drive shaft snapped
 

Golflover

Seaman
Joined
Sep 10, 2009
Messages
51
Re: 85 Mercruiser, 170 i/o 224: Won't go into fwd/rvs, overheating.

coupler or lower drive shaft snapped

Thank you for your kind response. Is there a way to determine which is more likely? And I imagine the coupler is more labor intensive and costly versus the lower driveshaft or am I out to lunch?
 

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
Re: 85 Mercruiser, 170 i/o 224: Won't go into fwd/rvs, overheating.

Drop the gearhousing (lower) and take a look at the vertical driveshaft. If you "smoked" the coupler you probably would have smelt burning rubber. Or easier yet, motor off, put in forward, turn prop counterclockwise. If prop locks and you can turn it CCW have someone look at the driveshaft behind the engine, if it is not turning it is the v driveshaft.
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: 85 Mercruiser, 170 i/o 224: Won't go into fwd/rvs, overheating.

Start the engine and look at the back of the engine and see if the shaft going to the drive is turning. The splines could be stripped out of the coupler and you wouldn't smell rubber burning. If it's turning, pull the top cap off the drive and see if the gears are gone.
 

Golflover

Seaman
Joined
Sep 10, 2009
Messages
51
Re: 85 Mercruiser, 170 i/o 224: Won't go into fwd/rvs, overheating.

Thanks, Terry for your insight and the practical advice.

Update: With the engine off and the throttle in forward, I spun the prop ccw. The yoke shaft; as it enters the coupler, easy was rotating in the female coupler. On closer observation; with the metal shavings present, it was clear the splines in the coupler were worn out as well as those on the yoke. I will be replacing both and completing some other maintenance issues while the motor is out.

Thanks again. Hopefully we'll be back on the water in a week.

Kurt
 

Golflover

Seaman
Joined
Sep 10, 2009
Messages
51
Re: 85 Mercruiser, 170 i/o 224: Won't go into fwd/rvs, overheating.

Thanks, Don, for your help and insight. You once again were spot on with my issue or at least where to look.

Update: With the engine off and the throttle in forward, I spun the prop ccw. The yoke shaft; as it enters the coupler, was easily rotating in the female motor coupler. Opon closer observation; with the metal shavings present, it was clear the splines in the coupler were worn out as well as those on the yoke. I will be replacing both and completing some other maintenance issues while the motor is out.

Thanks again. Hopefully we'll be back on the water in a week.

Kurt
 
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