1964 Johnson drops in and out of gear under load.

[Smokygrayson]

Hi, I wonder if anyone can give me a hint on my '64 Johnson, which make a "thud" noise, dropping out of gear, and back in when under power.

This is a new problem with the motor, despite it being an old motor, and only occurred after some maintenance fiddling with the gear shift cable to adjust the forward controls.

When shifting between forward, neutral and reverse, there is a linkage lever on the side of the motor which seems to control whether the engine is in forward or neutral. It's a long lever on the upper part of the motor on the right hand side (looking from the back). There is a small rod coming out from the motor which slides up and down this lever. The lever itself has smoothed notches where the rod 'pops in' when you engage the motor in forward, neutral, reverse.

Under load, the rod seems to slide gradually up the lever, jumping out of gear momentarily and then popping back down into the forward position. It doesn't stop the boat, it just makes a small bang and can't be good for the gearbox. It happens more, the faster you go.

If someone steers and I watch this happen, I can stop it by holding the lever forward.

The lever has a spring holding it tight. Is it possible that the spring has gone slack over nearly 50 years? Would it be a combination of all linkages or does it point to something more serious dow in the gears themselves?

I would appreciate any comments!

 

[B-Dozer]

Re: 1964 Johnson drops in and out of gear under load.

sounds like you need to adjust the linkage. there should be a small panel on the side of the motor above the lower unit with a couple of screws. remove the screws and you will see the linkage rods there should be a fitting that you can loosen and slide the rods up or down to adjust .

 

[boobie]

Re: 1964 Johnson drops in and out of gear under load.

Sounds like you need a new forward gear and clutch dog.

 

[Smokygrayson]

Re: 1964 Johnson drops in and out of gear under load.

Hmmmmmmm, thanks for the responses. I have an entire spare lower unit. I will look more carefully at the linkage rods, screws & linkages and then if I can't make headway there, will look at the gear & clutch dog.

 

[Smokygrayson]

Re: 1964 Johnson drops in and out of gear under load.

It does seem odd that it only, and suddenly began after an outboard mechanic started messing around with the forward controls....

 

[kfa4303]

Re: 1964 Johnson drops in and out of gear under load.

I'm thinking clutch dog too, based on the abrupt "thud". Some people describe it as like hitting a log. It only takes a small amount of ware for them to start to slip. Try adjusting the shift rod, of course, but if that doesn't fix it, then it's probably the dog.

 

[lindy46]

Re: 1964 Johnson drops in and out of gear under load.

sounds like you need to adjust the linkage. there should be a small panel on the side of the motor above the lower unit with a couple of screws. remove the screws and you will see the linkage rods there should be a fitting that you can loosen and slide the rods up or down to adjust .

The upper and lower shift rods can ONLY fit into the coupler one way. There are recesses in the ends of the shift rods and the coupler bolts must pass through those recesses. So this is not adjustable. You can disconnect the lower shift rod by completely removing the lower coupler bolt and check for play in the upper shift rod. Use a long-nosed pliers to reach in and grasp the upper shift rod, hold the shift lever firmly, then try wiggling the shift rod up and down. There should be NO play in the rod. Another test is to disconnect the remote shift cable from the shift handle and manually put the motor in forward. See if it still pops out of gear.

 

[Tim Frank]

Re: 1964 Johnson drops in and out of gear under load.

This would be a lot easier for you if you had an OEM manual.
Adjustments and troubleshooting steps are well laid out and explained.

 

[Smokygrayson]

Re: 1964 Johnson drops in and out of gear under load.

Thanks very much for the extra comments. I'm in Australia so it's tricky to get the OEM Manual but perhaps I can locate it in the US thanks Tim.

I had a look at the motor late last night (not the best time to do it). There is very little to adjust lindy46, you are right. There is a spring that tensions the shift rod, that might be sloppy. I'll look at the other things you mentioned too.

When I disconnect the remote shift cable and hold the shift lever in the forward position by hand, it does not pop out of gear. I'm wondering if the remote cable had less play then it might hold the shift lever more firmly in the forward position and stop it popping out.

 

[Tim Frank]

Re: 1964 Johnson drops in and out of gear under load.

Thanks very much for the extra comments. I'm in Australia so it's tricky to get the OEM Manual but perhaps I can locate it in the US thanks Tim.

Check ebay. Some good buys pop up often.

 

[Smokygrayson]

Re: 1964 Johnson drops in and out of gear under load.

Thankyou people for your comments. I have pulled the lower unit off and had a look at the dog clutch. Since I'm no outboard mechanic it's hard to know if there's a lot of wear there, but I'm talking to a mechanic about having it machined. It's incredible to think that all the force of the engine pushes on that one little surface.

 

[Smokygrayson]

Re: 1964 Johnson drops in and out of gear under load.

Mechanic says the clutch dog was the problem - it was badly worn. Again, I appreciate your responses. Thanks.