Reverse lock valve blew apart

[dozerII]

Was out this weekend with my buddy, him and his wife were in there boat and me and mine in ours. His boat is an 1981 Starcraft 18SS with a 1410 Mercruiser with a pre Aplha drive. Not sure what he did but before I could get to him, the drive had kicked up once in reverse and he did a neutral drop in to forward at about 2500 rpm just about throwing his wife out the back. When I got up along side and climbed aboard to take a look I found the whole upper Starboard side of the transom covered with trim oil and the arm in the Reverse lock out unattached to the valve. see Photo.

Can anyone explain this or has seen it before, I'm pretty well lost as to what he did.

 

[fishrdan]

Can't really tell from the pic, but it looks like the nut fell off the stud, allowing the movable arm to fall off the fixed mount. Or, something broke allowing the 2 halves of the reverse lock valve to separate.

Cheapest option would be to get a used one off Ebay, you'll have to run through the shift cable alignment procedure to get it set up again.

 

[dozerII]

Can't really tell from the pic, but it looks like the nut fell off the stud, allowing the movable arm to fall off the fixed mount. Or, something broke allowing the 2 halves of the reverse lock valve to separate.

Cheapest option would be to get a used one off Ebay, you'll have to run through the shift cable alignment procedure to get it set up again.

Thanks for the reply. The bolt is broke between the two pieces

 

[dozerII]

Can someone tell me if dragging the skeg up the ramp could cause this? As that happened during the previous days retrieval.

 

[dozerII]

Update, I took the valve off, then disassembled it on the bench and found the small internal bolt that retains the reverse lock arm had come loose allowing the arm to part company spewing out the trim oil. I cleaned everything up used acetone on the threads and threaded hole in the arm and re-assembled with lock tight. Now just have to re watch Achris's shift adjust video and it should be good to go.

 

[Alumarine]

Well done Glen.
Hopefully that's the fix.
You sure had a odd one there.

Maybe someone took it apart for some reason previously?

 

[dozerII]

Well done Glen.
Hopefully that's the fix.
You sure had a odd one there.

Maybe someone took it apart for some reason previously?

Thanks Marc

 

[dozerII]

Okay I have the trim and reverse lock fixed, but have a difficult time with the shift cable adjustment..

The shift cable has about six hours operating since new, prior to this little episode everything worked great.

What is happening now is I can set the cable tight in reverse and the LU won't quite lock in reverse, it dozen't matter how hard I pull on the cable, but if I go under the leg and push to the port side less than 1/16"on the shift dog it will lock in??

Any one? please some help, is it possible that when it shot into gear when he was trying to get it to go that it stretched the cable?

 

[dozerII]

Bump

 

[Alumarine]

Here's another bump for you!

 

[dozerII]

Thanks Marc, it's looking like no one wants to help with this one?

 

[GA_Boater]

Thanks Marc, it's looking like no one wants to help with this one?

Glen - Start another thread about the lower cable. The title of this one might be causing it to be overlooked. People look at the start of a thread and then see the rev. lock is fixed and assume she's all fixed up.

If I could offer some advice other than take it to a shop, I would.

 

[merc120_81]

Do you have any adjustment left on the slide where the lower shift cable end attaches? last steps in AChris's youtube video, on shift cable adjustment. I am in process of replacing my lower shift cable now, and hope, I don't run into the same problem as you. Good Luck.. hopefully someone else will chime in too.

Also.. stealing this from AChris's post to me on shift issues, re: cable: [COLOR=#6A6A6A !important]June 18th, 2017, 06:17 PM[/COLOR]


OK.. Just to clear up a few myths...

The load on the shift cable isn't even remotely high enough to stretch a STEEL cable... If the loads got that high, you'd be breaking other stuff way before the cable stretched...

What does happen is the inner liner of the cable gets worn, especially on the insides of any curves in the cable, which is why it's critical to set the cable up with the smoothest, biggest possible bend radius, just like it is in the Merc service manuals. When that happens, you'll see it as excess 'slop'/free play when the shift mechanism is 'locked' in one gear or the other.

Excess slop isn't always a worn cable. More likely it one of these....

1. Excess freedom in the shift slide on the bell housing end of the cable. The slide should be free to rotate on the cable, but with an ABSOLUTE minimum of axial movement (we're talking less than 0.2mm)...
2. Wear in the slidefork (where it engages with the upper shift shaft arm roller).
3. Wear in the upper shift shaft arm roller.
4. A loose upper shift shaft arm cross pin.
5. The 'shoe' on the bottom of the upper shift shaft is splayed slightly. (see this one a lot)
6. The foot on the top of the intermediate shift shaft is worn (never seen it, but it's a possibility)
7. Spines in the bottom of the intermediate shift shaft or the top of the lower shift shaft are worn (also, never seen this, but it is a possibility)
8. Wear in the shift crank on the bottom of the lower shift shaft. Splines or the crank itself.
9. Wear in the shift spool.
10. Wear/out of adjustment nut on the end of the spool shaft.
11. Lost tension in the spool spring.
12. Wear in the cross-pin or clutch
13. Wear in the dogs on the gears.. (common with drives that have been 'eased' into engagement.)

I've also seen a lot of bent intermediate shift shafts, which can lead to the shift mechanism binding up.

That just about covers the entire shift path....

Chris.......
====

 

[dozerII]

Glen - Start another thread about the lower cable. The title of this one might be causing it to be overlooked. People look at the start of a thread and then see the rev. lock is fixed and assume she's all fixed up.

If I could offer some advice other than take it to a shop, I would.

Thanks GA, I didn't really want to start a new thread cuz it all stemmed from the first problem.

 

[dozerII]

Do you have any adjustment left on the slide where the lower shift cable end attaches? last steps in AChris's youtube video, on shift cable adjustment. I am in process of replacing my lower shift cable now, and hope, I don't run into the same problem as you. Good Luck.. hopefully someone else will chime in too.

Also.. stealing this from AChris's post to me on shift issues, re: cable: [COLOR=#6A6A6A !important]June 18th, 2017, 06:17 PM[/COLOR]


OK.. Just to clear up a few myths...

The load on the shift cable isn't even remotely high enough to stretch a STEEL cable... If the loads got that high, you'd be breaking other stuff way before the cable stretched...

What does happen is the inner liner of the cable gets worn, especially on the insides of any curves in the cable, which is why it's critical to set the cable up with the smoothest, biggest possible bend radius, just like it is in the Merc service manuals. When that happens, you'll see it as excess 'slop'/free play when the shift mechanism is 'locked' in one gear or the other.

Excess slop isn't always a worn cable. More likely it one of these....

1. Excess freedom in the shift slide on the bell housing end of the cable. The slide should be free to rotate on the cable, but with an ABSOLUTE minimum of axial movement (we're talking less than 0.2mm)...
2. Wear in the slidefork (where it engages with the upper shift shaft arm roller).
3. Wear in the upper shift shaft arm roller.
4. A loose upper shift shaft arm cross pin.
5. The 'shoe' on the bottom of the upper shift shaft is splayed slightly. (see this one a lot)
6. The foot on the top of the intermediate shift shaft is worn (never seen it, but it's a possibility)
7. Spines in the bottom of the intermediate shift shaft or the top of the lower shift shaft are worn (also, never seen this, but it is a possibility)
8. Wear in the shift crank on the bottom of the lower shift shaft. Splines or the crank itself.
9. Wear in the shift spool.
10. Wear/out of adjustment nut on the end of the spool shaft.
11. Lost tension in the spool spring.
12. Wear in the cross-pin or clutch
13. Wear in the dogs on the gears.. (common with drives that have been 'eased' into engagement.)

I've also seen a lot of bent intermediate shift shafts, which can lead to the shift mechanism binding up.

That just about covers the entire shift path....

Chris.......
====

Thanks Merc 120, I followed your post and removed the drive and checked all the shift components between the cable and the shift shaft in the L/U. Found the slide adjustment was out a little, the roller on the shift arm was worn a little, the shift shaft was a little worn. I took some used parts I had in stock that weren't quite as bad and reassembled and now it works. This will tide us over till the boat comes in for a major rebuild.

 

[merc120_81]

Cool, Thank Achris, I stole his post to me