Clutch dog wear - ocean runner 150
#1

I have the lower unit apart on a project boat I picked up last fall. It would hang up going in reverse and grind for several seconds - often not even getting into gear at all. I checked cables to make sure they were fully actuating the shift shaft - and that looked good. I'm looking for an opinion on the amount of wear on the clutch dog and the reverse gear. I was hoping to find more definitive carnage - but maybe this is enough to confirm this is the problem?
*Note - one side of the dog is machined to have a slope - that is not wear. The wear in question is the rounded edge on the opposite side of the tooth.
1997 150 Ocean Runner



and the reverse gear which also has a little rounding of the teeth
*Note - one side of the dog is machined to have a slope - that is not wear. The wear in question is the rounded edge on the opposite side of the tooth.
1997 150 Ocean Runner



and the reverse gear which also has a little rounding of the teeth

#3
Admirals Club 


Your problem might be attributed to worn lower engine mounts. They're under the clamshell covers on each side of the midsection. I had a similar issue w/my last motor, an '01 Johnson. It started to hang up going into reverse. When the engine mounts break down, the powerhead shifts a fraction of an inch, which is just enough to cause the shift rod to bind. We replaced mine and the problem went away. Not a difficult job.
#4

Your problem might be attributed to worn lower engine mounts. They're under the clamshell covers on each side of the midsection. I had a similar issue w/my last motor, an '01 Johnson. It started to hang up going into reverse. When the engine mounts break down, the powerhead shifts a fraction of an inch, which is just enough to cause the shift rod to bind. We replaced mine and the problem went away. Not a difficult job.
#5
Admirals Club 


There was a thread here about a year ago where someone detailed the replacement process. As with any outboard-related job, the biggest threat is breaking a bolt off. So if you have to replace them, give the inner bolts a good soaking or Kroil or PB Blaster.
#6
Senior Member

While there is a bit of wear there, it does not seem like enough to make it jump out of gear, if the cables and shifter rod are adjusted right. Might be as Cobia said above....
#7

Yea - it doesn't feel like enough wear to be my issue - but i'm starting to run out of parts to blame it on. I'll double check the motor mounts - but when iI was running some tests to find the issue - the shift linkage was fully activating so i don't think there is any binding there. Unfortuatly - the motor is off the boat and the boat is under restoration so i can't do a lot of testing for a couple months. I may just replace the clutch dog and hope for the best....
#8

It wasn't jumping OUT of gear btw - it was hanging up while going into gear. It would just grind for an extended period of time without engaging.
#9
Senior Member

Well that makes sense, due to the small amount of wear there. Grinding going into gear, usually is because the shift is happening too slowly, or the shift linkage is not allowing enough throw in that gear for it to engage quickly as a dog clutch must for there to be no grinding. I had this with my Cobra drive which has a very similar lower unit to the OMC V6 outboards. What it turned out to be was the remote cable adjustment on the shifter bellcrank on the engine. It was allowing enough throw in one direction but not the other. The I/O is a bit different in practice in that there are 2 cables, one that goes from the remote control to the shifter bellcrank on the engine, the other cable goes from the other end of this same bellcrank thru the transom to the lower unit. Both have to be in perfect adjustment for it to shift right. In my case the remote cable adjustment had changed on the bellcrank just enough to not engage fully and make it grind. Make sure that you do have equal throw on either side of neutral and your shift cable is not getting sticky. On the Cobra you measure the drag with a fish scale, can't exceed 2.5 lbs. If the cable was sticky I'd expect it to be a problem in fwd and rev, not just one. I wish I could help more, I am good with the Cobras but don't know the OBs.
#10

Well that makes sense, due to the small amount of wear there. Grinding going into gear, usually is because the shift is happening too slowly, or the shift linkage is not allowing enough throw in that gear for it to engage quickly as a dog clutch must for there to be no grinding. I had this with my Cobra drive which has a very similar lower unit to the OMC V6 outboards. What it turned out to be was the remote cable adjustment on the shifter bellcrank on the engine. It was allowing enough throw in one direction but not the other. The I/O is a bit different in practice in that there are 2 cables, one that goes from the remote control to the shifter bellcrank on the engine, the other cable goes from the other end of this same bellcrank thru the transom to the lower unit. Both have to be in perfect adjustment for it to shift right. In my case the remote cable adjustment had changed on the bellcrank just enough to not engage fully and make it grind. Make sure that you do have equal throw on either side of neutral and your shift cable is not getting sticky. On the Cobra you measure the drag with a fish scale, can't exceed 2.5 lbs. If the cable was sticky I'd expect it to be a problem in fwd and rev, not just one. I wish I could help more, I am good with the Cobras but don't know the OBs.
Now that I think about it - i wonder if the sludge oil / additive or whatever was in there was causing problems. This shit was thick. The previous owner said it had trouble going into reverse when it was cold - but was fine when warm. (i did notice it was slightly better when warm) It's possible the gear oil was too thick - and it thinned out when warm and was able to engage properly. Who knows. I think i'll start w/ the clutch dog and revisit later if it still sucks.