A different kinda gear issue

[VBtravisD]

I have a 77 Johnson 55hp. I am having an issue with getting both forward and reverse. I have tried fine tuning the linkage. With the motor off, I could get it to go into forward and engage the prop... then reverse. I got out on the water this weekend, and reverse was horribly slow even if I throttled up. But forward worked just fine. Took it out for a little cruise, it got the boat up on plane and no issues. Stopped to fish for a bit, turned on the motor... NO FORWARD!? Reverse worked great then! I couldnt believe myself. I adjusted the thumb screw so I at least had forward gear. Fished the rest of the day. I did have 1 issue where after sitting for a bit, the motor revved up but had an issue "going into forward"... it would clunk and then go into forward, but after a little bit of coaxing. Once it was in gear it ran great, pushed the boat along just fine. Is this a linkage issue? Or is this something in the gearcase?

Thanks for any info you guys can provide!

 

[oldcatamount]

Re: A different kinda gear issue

I'd check the prop first. You are describing a "spun prop". Have you hit anything or been in the sand with it lately? Take a felt tip marker and make a mark on the prop and hub. Take the boat for a short ride. If the marks don't line up anymore when you come back in, then the prop is bad and will need repair or replacement.

 

[VBtravisD]

Re: A different kinda gear issue

Gotya... I will mark it and check. The only funny part is that my motor doesnt "slip" when running. It is only from idle to gear engagement that I have an issue.

 

[oldcatamount]

Re: A different kinda gear issue

Well, if the prop checks out ok, then I'd say the clutch dog is probably shot. If the dog is gone, the forward and reverse gears are probably bad as well. Let's hope that's not the case.

 

[VBtravisD]

Re: A different kinda gear issue

I am pretty mechanically inclined, so I am not too worried about dissasembling the gearcase. However, should I replace all the seals once I disassemble? Or if they are in good condition, can they be reinstalled?

And to answer your question earlier... Yes, I was fishing with my brother over the Christmas holiday and the knuckle head ran us into a sandbar. We were idling and the motor cut off. I managed to get it fired back up. I'm hoping it is just the prop. We'll see.

What are the symptoms of a worn out clutch dog?

BTW, thanks a lot for the help!

 

[boobie]

Re: A different kinda gear issue

First thing, check the g/c for any water in it. Second thing, check for any play from the control box on back in your shift system to the mtr and also the mtr.

 

[VBtravisD]

Re: A different kinda gear issue

I pulled the prop last night... the prop nut was barely finger tight. The inside of the hub did not look tore up, but I understand that it can be difficult to tell a spun hub by eye. I drained the lower unit oil, it was still very viscus, but an odd milky green color. I do plan on checking my throttle to see if there is any play in it too.

 

[oldcatamount]

Re: A different kinda gear issue

A clutch dog will wear out with use. The most common way to wear out the dog, is to shift gears to slowly. Some people will gently push (or pull) the shifter and let the dog grate until it engages. You should use a smooth, swift action to engage the gears and not let them grate. Pulling your gearcase apart isn't to hard actually, but, I would strongly suggest that you get a Repair Manual. A gearcase job can get expensive real quick if you are guessing.

 

[VBtravisD]

Re: A different kinda gear issue

Yeah, I see that. I downloaded a manual for my outboard. And I priced new forward and reverse gears and a clutch dog. It does add up quick, but I would feel much better knowing that my outboard was much more reliable.

 

[CharlieB]

Re: A different kinda gear issue

How OLD is the shift cable?

As the cable ages, it wears grooves in the nylon lining of the housing, the added distance in the cable path causes erratic shifting as the cable cannot push AND pull a load the same precise distance as a new cable. You can adjust so as to consistantly shift into Forward OR Reverse, but NOT BOTH.

At very well could be that it is simply time to replace the cable.

 

[steelespike]

Re: A different kinda gear issue

You may have shift cable or control box issue.I assume it is a single lever control.
As you move the lever it moves both throttle and gear lever in the motor.
I've never had to do a control box but no doubt if something was worn or broken it would
make shifting/throttle movement unpredictable.
Running into a sand bar at idle isn't likely to cause a hub failure.
Your reving when trying to shift is more likely the cables or control acting up.
Its easy enough to check the hub so you migfht as well check it out.
Disconnect the shift cable and see if it will shift by hand.

 

[VBtravisD]

Re: A different kinda gear issue

Yep, it is a single throttle which controls both linkages. These are the original control cables too, and I got the motor second hand. When I first came across the issue, it did seem more like a linkage problem to me due to the fact that it always engaged in forward well. I am going to take a look inside my control box this afternoon also.

 

[Silvertip]

Re: A different kinda gear issue

There is only ONE way to adjust the throttle and shift cables and adjusting them is NOT an adjustment for wear - it is an adjustment for length. Disconnect the shift cable at the engine. Put the shift linkage on the engine in NEUTRAL. Put the lever on the control box in NEUTRAL. Now bring the end of the cable up tothe atttachment poing on the engine. Without pulling or pushing the cable, adjust the thumbwheel (the trunion) so the cable end and the shifter line up exactly. Reattach the cable. Remember, you should always have the engine running when attempting to shift. Just like a stick shift car the gears (the clutch dogs on an outboard) may not be lined up. If the shifting is still erratic, NOW check the box first rather than digging into the lower unit. Lastly - why would you consider using old lower unit seals since you have the unit apart. That is almost guaranteeing a leak. Warn clutch dogs don't generally cause trouble shifting but they do cause the jumping out of gear under power. When operating an outboard in reverse the prop is running in a very inefficient manneer since it is running backwards so performance is limited. The engine is also RPM limited in reverse as well to keep you from filling up your boat with water.

 

[Joe Reeves]

Re: A different kinda gear issue

Did this engine ever shift properly... and if so, have you done any maintenence (change water pump, whatever) to the engine and shortly thereafter had this problem arise?

Many boaters unknowingly turn the threaded shift rod in the lower unit one way or the other, changing the length measurement of the rod which is critical. If you might have done this, it would create your problem. The measurement (as follows) is from the top main surface of the lower unit to the center of the top shift rod hole with the unit in neutral. NOTE the difference between the manual and electric start models.

1975 - 1978 - 50, 55, 60hp Electric Start = (S) 15-29/32" - - (L) 20-29/32" plus/minus 1/32" Have shift rod in neutral.

1977 - 1981 - 50, 55hp Manual Start = (S) 16-23/32 - - (L) 21-23/32" plus/minus 1/32" Have the shift rod in neutral and the offset to the rear

 

[VBtravisD]

Re: A different kinda gear issue

I have only run the motor 4 times. The first outting I did not have an instance in which I needed reverse and honestly didnt think to test it. The second outting I realized I did not have reverse. I haven't had an issue with forward until I started adjusting the trunion in order to get reverse (after the 2nd trip). I did the adjustment as listed by Silvertip above, with the throttle in neutral and the cable disconnected. I would then put the throttle in forward, then see is the prop engaged in forward by turning the prop by hand. It would lock into place and the flywheel would attempt to turn. I would not be able to turn it the opposite direction. These cables are old, and off of a boat much longer than mine. I have tried to run them in a manner that does not bind them, with a large loop at the outboard.

I have not dropped the lower unit because the motor has always had a good stream coming from the cooling line. But that is not saying that the previous owner hadn't inadvertently adjusted the shift rod. It wouldn't be bad if it is a control box issue, and excellent if it is just a 25 dollar cable problem. I guess this is my reasoning to buy proper length cables anyway.

Does the fact that while under load and at higher rpms the motor does not slip or jump in rpms help eliminate the probability of issues within the gearcase?

I really do appreciate all the info and guidance you guys have given me. Hopefully I will be able to get this problem figured out soon.

 

[Joe Reeves]

Re: A different kinda gear issue

It might be a good idea to check with the eprevious owner if possible to see if he had installed a water pump and to ask if he might have possibly changed that shift rod measurement.

To see if the problem is with the controls, cables, whatever... simply disconnect the shift cable at the engine temporarily and shift it into gear by hand directly at the engine's shift linkage. If the problem still exists, the problem is obviously with the engine. As such (engine problem), if it were me, I'd drop the lower unit to check that rod measurement.

 

[VBtravisD]

Re: A different kinda gear issue

Joe, if I am reading your post correctly... I have a '77, 55 hp, electric start, long shaft motor.

 

[Joe Reeves]

Re: A different kinda gear issue

1975 - 1978 - 50, 55, 60hp Electric Start = (S) 15-29/32" - - (L) 20-29/32" plus/minus 1/32" Have shift rod in neutral.

If your engine is a long shaft engine (20" shaft model), the measurement should be 20 and 29/32", give or take 1/32".

 

[the bareman]

Re: A different kinda gear issue

1975 - 1978 - 50, 55, 60hp Electric Start = (S) 15-29/32" - - (L) 20-29/32" plus/minus 1/32" Have shift rod in neutral.

It should not be between anything. If your engine is a long shaft engine (20" shaft model), the measurement should be 20 and 29/32", give or take 1/32". That is... measure 20", then add 29/32 of an inch.

Ok you all seem to know what your talking about let me run this on by you.I have a 40 hp johnson plssm and i took it out and it ran fine but i started hearing a noise when in gear like a knocking noise,And now when i start it with the hose and put it in gear it knocks sounds just like a car motor getting ready to throw a rod What could this be.Please help its a 2000 model electric t/t with remote.When you all say controll box are you talking about the remote box at the console?Sorry prob a silly q?Thanks in advance Alan.

 

[boobie]

Re: A different kinda gear issue

Please read the rules at the top of this forum. It's not nice to hi-jack a thread.