86 Cobra stuck in reverse, wait, there's more

[john744]

Greetings to all. I been an observer for here for a few years and am confident someone may have run across this. I have a 1986 Renken 2600 Classic with an 86 OMC Cobra 5.7 (Chevy 350). It ran pretty good last year. Just lanunched it 5 days ago (had to replace manifolds and risers & fix the stuck exhaust valve, yes I did it myself). Put it in the water (salt) and she fired right up, sounded good. Put her in reverse & backed away from the launch dock, shift into forward.... oh ohhhhhh stuck in reverse. Turn motor off. Will go into neutral, start, shift into forward & all is good. Will shift out of forward into neutral with no problems. Will shift into reverse with no problems, but will not shift out of reverse while under load. (AH yup, I understand this concept).

First thought is the ESA. Yes, I thought so too, but it does work, in fact it will kill the motor (idle set really low). It does have the new RED shift cable (I put it 3 years ago). Yes, I do have the Factory shift alignment procedures (thanks to those here & Stuart Hastings). I followed the procedure to the letter but still no resolution.

So in my own whack way, I tried something. I disconnected the RED transom cable completely. With the engine running & holding it in my hand, I can shift from neutral into forward and back into neutral all day long (yes even with out the aid of the ESA). If I shift from neutral into reverse, no problem, but try to shift from reverse into neutral and the cable will move into position, will even go out to the forward position, and will go back to the neutral position and back to the reverse position. How is this possible? My bell crank must be in the shift rod receiver (item 36 in photo) how else could I possibly shift in and out of forward and then into reverse. I understand the reverse is under load and doesn't want to disengage the clutch dog, but why does the cable move? The shift rod receiver is indexed in the rear so I can't see that slipping to one side (OR CAN IT?). But it always works going into or out of forward. If I get hung up in reverse, I just turn off the engine (or let the ESA kill it) and I can go back to neutral and into forward. The cable is harder to pull than it should be, but it does move into the neutral and forward positions and back to reverse without the clutch dog disengaging. Any thoughts ????

 

[bruceb58]

Re: 86 Cobra stuck in reverse, wait, there's more

Time to replace the lower shift cable. Tilt the drive up and look at the cable as it enters the drive on the starboard side. I bet that cable housing is going to look not so good. That is where these fail.

 

[bruceb58]

Re: 86 Cobra stuck in reverse, wait, there's more

I know you said you replaced it 3 years ago. They just fail often!

 

[john744]

Re: 86 Cobra stuck in reverse, wait, there's more

You think perhaps the outer jacket is colapsing as I pull the inner cable. It doesn't feel like the out jacket is moving, and I can definitely feel detents in neutral and forward positions. I will take a look though.

 

[john744]

Re: 86 Cobra stuck in reverse, wait, there's more

Hi Bruce, let me just add/clarify something........... When I say the cable is harder to pull than it should be, this is only when engaged in reverse. If I'm in neutral and attempt to shift, the pull/push force seems normal. If I'm in forward and shift into neutral, it seems normal. If the motor is off, it feels normal in all directions. Also, if the outer jacket were collapsing, why would I feel the detents?

 

[a70eliminator]

Re: 86 Cobra stuck in reverse, wait, there's more

It sounds like a unique problem, a worn cable is usually culprit but you may just have something else going on like a piece of broken flapper wedging itself between the shift rod and the exhaust housing then shutting the engine off it falls back and is out of the way again, it highly unlikely just an example of something unique, you'll need to pull the drive to get to the bottom of it.

 

[bruceb58]

Re: 86 Cobra stuck in reverse, wait, there's more

Also, if the outer jacket were collapsing, why would I feel the detents?

If the outer cable jacket collapses its going to take more cable throw as the housing collapses.

Take a look at the cable housing. Should be pretty obvious. I would also pull the drive anyway. You should be pulling it annually. You can look at the area that the bell crank is in to see if there is a build up of crud in there which happens on salt water boats(not sure if you use yours in salt water).

Also, do you leave your drive stored in the down position. Its much easier on that cable if you do among other things.

 

[bruceb58]

Re: 86 Cobra stuck in reverse, wait, there's more

Ibut you may just have something else going on like a piece of broken flapper wedging itself between the shift rod and the exhaust housing then shutting the engine off it falls back and is out of the way again.

I don't know if could imagine anything really jamming that rod. Its thin and the shift fork is engaged with the bellcrank so nothing in the exhaust could interfere with the fork.

 

[a70eliminator]

Re: 86 Cobra stuck in reverse, wait, there's more

I tried to draw a picture of what I was thinking, I know it's highly unlikely if even possible but I've seen some strange things before.

 

[bruceb58]

Re: 86 Cobra stuck in reverse, wait, there's more

I tried to draw a picture of what I was thinking, I know it's highly unlikely if even possible but I've seen some strange things before.

You know what, I had forgotten what it looks like. I agree that it is more possible than I first thought.

I still think its a bad cable though.

 

[john744]

Re: 86 Cobra stuck in reverse, wait, there's more

Just put her in so it breaks my heart (and doesn't help my back either) to pull her out after 5 days. I do pull the drive annually & yes there was that lovely crud in there. I attributed that to the tear in the bellows (along with the annual Gimbal Bearing replacement) which I have replaced. The boat is moored in Salt Water, and I used to raise the drive but stopped about 4 years ago. Got plenty of water under her even at low tide ( and figured it helps with bellows longevity).

To recap this springs activity. Pulled the motor to replace the oil pan (bad leak at the dipstick tube fitting). While outdrive was off, spotted tear in bellows, replaced. Also, replaced gimbal bearing. Bad manifolds & risers caused sticky #7 exhaust valve. Tried to plane the old ones but too far gone, so bought new mani's & risers. Pulled the head & replaced the bad valve. New MARINE head gasket & intake manifold gasket. Put her all back together, used my brandy new engine alignment tool, drop her in the bay, & then run into my stuck in reverse problem.

I really apreciate the help & advise offered here. Just can't figure out what's going on. Will post any findings.

Thanks guys !!!

 

[john744]

Re: 86 Cobra stuck in reverse, wait, SOLVED!

Re: 86 Cobra stuck in reverse, wait, SOLVED!

Wanted to say thanks to all for your help on my Cobra Stuck in Reverse problem and let you know what I found. It was indeed the cable. The problem got progressively worse. When I went to to take her out of the water, I could not shift into forward at all & had to be towed. When I pulled the drive off, I found the SHIFT CABLE GUIDE Item #98 sagging. Further disassembly revealed the long brass sleeve on shift cable had broken away from the threaded collar.

This allowed the top roller of the Bell Crank Arm to jump out of the slot in the guide. Actually, the guide deflected downward and pulled away from the arm under tension. With the roller out of the slot, I can see how reverse was still possible, but forward was out of the question. Really don't know how or why this broke, but wanted to share this with you. Thanks again for you help.

 

[a70eliminator]

Re: 86 Cobra stuck in reverse, wait, there's more

When you were holding the cable by hand and shifting, you were pushing the sheath with one hand while pulling the cable with the other, which kept that broken part planted well enough to effect a shift, making it seem ok when it wasn't. Thanks for posting the follow up, some people just go their merry way until something else breaks.

 

[Lou C]

Re: 86 Cobra stuck in reverse, wait, there's more

Again thanks for the follow up from a fellow Cobra owner. BTW, if you want to cut down on the deposit build up in the bellcrank cavity, clean out that area well....then pack it with OMC/Bombardier triple guard grease and then when you re-install the drive coat the gasket well with OMC/Bombardier gasket sealer on BOTH sides, that will keep out most of the salt water and the bellcrank will work smoothly....

 

[bruceb58]

Re: 86 Cobra stuck in reverse, wait, there's more

OMC also came out with a new bellcrank endcap/bearing that has a grease fitting on the outside. This came out in last year or so of OMC. You use that fitting to lube the whole area, basically filling the cavity with grease.