Hit something with Prop

[AtlDawg]

Hi Guys,<br />Last night I hit somthing with my 73 Chrysler 70 while at WOT, possibly a stump or log. I heard and felt it and the engine reved up but stopped moving the boat. It will go into gear at idle and seem fine at idle speed with no vibration. After getting out of water saw the prop nut slipped back a half inch or so with the shear pin still in place. Of course the prop is back the same distance and the cover where the prop shaft comes out of the lower engine is sticking out a little. What all should I check after removing the prop?

 

[The Marine Doctor]

Re: Hit something with Prop

You will have to disassemble the gearcase and check for damage, as the brg carrier has been pulled back. This changes the tolerances of the gears, which are always in contact and moving. <br /><br />You will also have to check the bottom housing to see if the brg carrier bolts have pulled out. Helicoils might be necessary or replacment of the bottom housing.<br /><br />TMD

 

[force01]

Re: Hit something with Prop

cliff,<br />if you pulled that bearing carrier out of place you maybe shopping for a new lower unit soon. You arent supposed to go WOT in the dark. Bret

 

[AtlDawg]

Re: Hit something with Prop

Thnx for the reply guys. It happened well before dark. I wasn't stupid enough to run WOT after dark just stupid enough to run in the stump and log filled lake of West Point. So the prop is off now and the shaft splines looks ok. I think the entire shaft might have been forced out 1/2 an inch or so. the 2 allen head bolts that hold the cover on are ok, looks like the extra 1/2 inch came from inside the foot. It did shift and run fine at idle speed to get home with no vibrations so I'm hopeful. I will tear it down this weekend. Does this kind of internal problem usually require a new foot or can the bearing carrier or whatever is inside be replaced/repaired?

 

[The Marine Doctor]

Re: Hit something with Prop

Unfortunately there is no telling until its torn down.<br /><br />TMD

 

[AtlDawg]

Re: Hit something with Prop

more info... motor is slipping out of gear. I can spin the prop when motor is in forward but not in reverse. As I spin it I see the shift arm moving up slightly and not fully engaging. If I press down on it slightly it engages. Maybe I didn't hit anything as this happened at WOT and it just seemed that way. Could this be a shift pin problem? I accidently removed it when changing the lower unit oil but it went right back in and I ran 3 trips to the lake after that without problems. Drained my freshly changed gear oil today and it was fine and no water in lower unit. Also, when I removed the prop, there was ground up plastic under the hub. Maybe what used to be a spacer or gasket and the prop rides back against the foot now as I spin it. Any thoughts????

 

[The Marine Doctor]

Re: Hit something with Prop

The ground up plastic is probably fishing line.<br /><br />It sounds like the engine is jumping out of gear.<br /><br />TMD

 

[AtlDawg]

Re: Hit something with Prop

Are there any common problems to cause an engine to jumps out of gear? Everything has been running fine and this started suddenly. It jolted so hard I thought I hit something or maybe I did. Nothing seems bent or loose and it will stay in gear at idle but when I throtle it jumps out. Also it seems just a very slight push down on the shift rod makes it engage in gear. The plastic is what's left of some spacer. There was a small piece big enough to identify like a small black shim or something. ??????

 

[The Marine Doctor]

Re: Hit something with Prop

There are no shims behind your prop. Like I said..its probably fish line. It heats up and melts and fuses together, looking like a spacer.<br /><br />When shifting gears...do you push with a positive thrust?<br /><br />Worn bushing or control box will also cause this kind of problem.<br /><br />Shifter shaft will do the same.<br /><br />In any case...I suggest you pull the gearcase apart, check for the amount of damage on the gear/clutch face..as there will be some if it has jumped out of gear.<br /><br />^That is sound advice^<br /><br />You might be able to save one or both the components if you do as I say. If not you will have to replace both.<br /><br />Find out what is causing the jumping out of gear before it gets really expensive.<br /><br />TMD