Clutch dog replacement on 1962 40hp

[thymetz]

Hi, I've got a manual shift big twin that makes the dreaded klunk sound
at light throttle in forward gear. (feels like skipping)
I want to replace the clutch dog and am wondering if this can be done while
motor is connected to boat transom ? It was not too many running hours since
I replaced h20 impeller/housing and went thru the gearcase with new seals/bearings/gears and a slightly used dog. I have now purchased a new dog from ebay and it looks to be slightly different from the one that originally
came from my motor. Maybe they have been improved upon. Any one else run into this?
I do have a manual and could really use this forums expertise.
Thanks

 

[Daviet]

Re: Clutch dog replacement on 1962 40hp

Just drop the lower unit, like you did to replace the water pump, turn it upside down and remove the screws holding the skeg on. Remove the phillips screw holding the piviot and remove skeg. That will expose all the gears. Follow your manual and you will be fine.

 

[tmcalavy]

Re: Clutch dog replacement on 1962 40hp

That happens when someone gets the part number wrong, or when someone before you put a newer/older lower unit on your motor. You need to compare the number of splines on both clutch dogs...last time I encountered this, I had to send my clutch dog supplier a digital photo of the dog I was replacing. Took two tries, but we got it sorted out.

 

[thymetz]

Re: Clutch dog replacement on 1962 40hp

Just an update to share my discoveries. Once I opened the gear box and took things apart I learned some stuff. The new clutch dog from ebay was a #312866 which fits the '68-'76 35/40 hp models. My '62 needed a dog #305105
which I was able to purchase locally for about $60. I switched forward and reverse gears by pressing out the bushings and swapping them too.
But this didn't change the area where the dog engaged (still hits on the same worn edges) But what really messed me up was, one of my gears was for the larger #312866 dog (ball detent in prop shaft, nicer setup). I was able to track down the correct gear for my '62 from a local guru who had some extra used parts. He explained that stretching the spring on the shift lever by the powerhead would help it stay in gear. I choose the best of my two gears for my forward and put in the bushing it needed and everything else back in place including the right new clutch dog. Used a new o-ring and spaggetti seal with a touch of rtv silicone at the cut edges. I used the OMC gasket sealer to help seal the the gear case halfs and all bolts, which I HOPE was a good choice. (I had used 3M weatherstrip adhesive (yellow snot) before and that was really hard to get apart and clean off this time around)
Filled the gear case with new fluid and tested the motor in a bucket. Then
tested in the bay only to find my prop was spun. But it did seem to stay in gear and shifted fine, Yea! so far....So now my prop a aluminum 10 3/8 x 11 1/2 is toast, but the "guru" I met suggested I press the hub back in and drill, tap and thread three 1/4 bolts holding the alum to the bronze hub and repair the prop I have. Meanwhile, I have gotten another used prop off ebay which is made of bronze and quite a bit heavyer (same dia w/slightly less pitch)
Does anyone run these old bronze props anymore? Or are they harder on the clutch dog and gears than the aluminum counterparts? What about the threaded bolt fix for old props?
Thanks to all those who replied and those who may still. What a great forum this is, couldn't do it without you'all.

 

[Johnny Too Bad]

Re: Clutch dog replacement on 1962 40hp

The old bronze props are definitely harder on the clutch dog and gears because of how heavy they are. I don't think anyone runs them anymore. From what I've seen, they just put them on for shows and meets. I would suggest trying to find another aluminum prop somewhere (I see them on ebay all the time) especially since it sounds like your gears are already a bit worn.

 

[Willyclay]

Re: Clutch dog replacement on 1962 40hp

My manual says do not use bronze props on these models due to what Johnny said above. Any good prop shop can "rehub" your prop. FYI, OMC referred to the rubber sleeve as a clutch and it slips intentionally when the prop strikes something hard or gets old and the rubber deteriorates. Also, the pin that goes through the bronze prop hub and the propellor shaft is a drive pin, not a shear pin. The pin should be made of stainless steel. If you follow the "guru's" advice and make the bronze hub fixed with bolts, your motor will not have any slip/shear protection for the really expensive moving parts. Good luck!

 

[samo_ott]

Re: Clutch dog replacement on 1962 40hp

The OMC dealers can re hub those props relatively cheaply I hear...

 

[F_R]

Re: Clutch dog replacement on 1962 40hp

The OMC dealers can re hub those props relatively cheaply I hear...

Most dealers simply send it out to the prop shop as soon as you leave. It takes special equipment to spin the new hub in.

 

[cougar1985]

Re: Clutch dog replacement on 1962 40hp

Most dealers simply send it out to the prop shop as soon as you leave. It takes special equipment to spin the new hub in.

correct in the most part,my buddie gets props from dealers all the time to re hub or re do .im sure there,s one or 2 that do their own work but it is a specialty job better left to pro,s.when i say theres one or 2 that maybe do their own work im talking about boat dealers that are maybe big enough or busy enough to afford to do so,though they seem extreemly rare.

 

[lindy46]

Re: Clutch dog replacement on 1962 40hp

Just had a hub replaced - about $35.