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1980 Johnson 35 HP 2-stroke - problem with gears

P

paulinho

New member
Hello everybody!

I encountered a strange problem when test running my 35hp Johnson from 1980 after removing the lower unit in order to install a new water pump. When reassembled, I can only shift from neutral to reverse gear (actually, when set forward, the engine is on neutral and when set on neutral or reverse, the motor is on reverse). Does any one of you know, what might cause this? What did I do wrong?

I was trying to follow SELOC manual when replacing the waterpump. I switched gears from forward to reverse during when reassembling the motor to have the shift rod connected. However, to get the splines on driveshaft right position, I rotated the driveshaft from the propeller instead of rotating the flywheel as instructed when installing the lower unit.

I noticed the manual warning to "Be extremely careful to prevent the driveshaft being pulled up and free the pinion gear. Otherwise the lower unit must be dissassembled to align the pinion gear and driveshaft." but I don't recal lifting it up att all during the process. Is it possible that the problem would be related to alignment of driveshaft and pinion gear eventhough the reverse gear works but is bring engaged too early (already on neutral)?

As the motor hasn't been used for ten years prior yesterday, could it be possible that the shift rod has become stuck with the casing somehow? I gave the motor a normal service (new lower unit gear oil, new spark plugs etc.) but it's highly likely that I missed the shift rod when greasing other parts (with easy access).

Any help is highly appreciated!
 
You did not remove the shifter pivot pin near the oil drain plug I hope!

The symptoms you describe sound as though you have not fully engaged the upper shift rod with the lower shift rod.
You did not unscrew the lower shift rod did you? AFAIK it should be screwed in fully but the manual will tell you if not.

Had a quick look at the manual . I notice the instructions for re connecting the upper and lower shift rods change in 1980. You did not quote the model number. Are you sure about the year
 
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vics said:
You did not remove the shifter pivot pin near the oil drain plug I hope!

The symptoms you describe sound as though you have not fully engaged the upper shift rod with the lower shift rod.
You did not unscrew the lower shift rod did you? AFAIK it should be screwed in fully but the manual will tell you if not.

Had a quick look at the manual . I notice the instructions for re connecting the upper and lower shift rods change in 1980. You did not quote the model number. Are you sure about the year
Click to expand...

Thanks for the reply! The model number is J35BACSM and the serial number B012201. It's made in Belgium.

I didn't touch the Phillips head screw at all so I guess the problem is in the shift rod. I loosened both of the brass nuts holding the lower and upper parts of the shift rod together. At first, the nut on lower shift rod was stuck on the rod and whole lower rod was rotating the same time I tried to get the nut to go down it's threads on the rod. So at least I didn't unscrew the lower shift rod intentionally but it might have loosened during the process.
 
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Okay. Model number confirms that it is a 1980 model

Had a quick read of the manual which seems to suggest that to undo the joint between the upper and lower shift rods you unscrew the upper nut while counter holding the lower one. (In fact the exploded parts diagram does not show the lower one as a separate part, rather as part of the lower shift rod). I hope you have not stripped the thread on the bottom of the shift rod or done any other damage.

When you reassemble the shift lever should be moved to the reverse position before tightening the connection to ensure that the upper rod is correctly inserted into the coupling.
 
vics said:
Okay. Model number confirms that it is a 1980 model

Had a quick read of the manual which seems to suggest that to undo the joint between the upper and lower shift rods you unscrew the upper nut while counter holding the lower one. (In fact the exploded parts diagram does not show the lower one as a separate part, rather as part of the lower shift rod). I hope you have not stripped the thread on the bottom of the shift rod or done any other damage.

When you reassemble the shift lever should be moved to the reverse position before tightening the connection to ensure that the upper rod is correctly inserted into the coupling.
Click to expand...

Thanks for the reply - let's hope I didn't damage the lower shift rod! I really thought that the nut at the end of the rod had threads and was moving but guess I didn't notice the whole lower part of the shift rod rotating... However, on this YouTube video (from 00:45 onward) and this YouTube video (from 03:50 onward), I can see the nut of lower shift rod (or just the rod) rotating. Of course, the models are not the same (and the motors might not have been fully functional after the service) but the upper and lower parts of the shift rod seem to be attached the same way as in my motor.

Do you think I should just try to reassemble the shift rod (with shift lever moved to reverse position) or first try to check that the lower shift rod is correctly in place?

Can you confirm that the rod should tighten when rotated clockwise? Anyway, I'll try to be gentle with the shift rod and rotate it by hand in order to check if it's correctly attached or not. The other idea I got is to rotate it CCW (since I've obviously been tightening it all the time when rotating the nut CW) and try to see if the color of the rod surface would change indicating the previous height (I guess only the spark plugs had been changed since the 1980's as the water pump housing and the impeller looked like the original ones when replaced - that's why I would assume being able to see a slight change in the rod color caused by dirt build up etc.).

EDIT: Of course it's as possible that the lower shift rod is sitting too high at the moment since I rotated it CCW when tightening the nuts... I guess this is more likely to explain (in contradictory to the shaft sitting too low), why reverse gear is being engaged both at neutral and reverse position of the shift lever?

So probably it's wisest to try to adjust the lower part as low as it goes and then, when tightening the connection, to ensure that I'm holding the lower nut on place and rotating the upper nut only (as you already described)?
 
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paulinho said:
Thanks for the reply - let's hope I didn't damage the lower shift rod! I really thought that the nut at the end of the rod had threads and was moving but guess I didn't notice the whole lower part of the shift rod rotating... However, on this YouTube video (from 00:45 onward) and this YouTube video (from 03:50 onward), I can see the nut of lower shift rod (or just the rod) rotating. Of course, the models are not the same (and the motors might not have been fully functional after the service) but the upper and lower parts of the shift rod seem to be attached the same way as in my motor.

Do you think I should just try to reassemble the shift rod (with shift lever moved to reverse position) or first try to check that the lower shift rod is correctly in place?

Can you confirm that the rod should tighten when rotated clockwise? Anyway, I'll try to be gentle with the shift rod and rotate it by hand in order to check if it's correctly attached or not. The other idea I got is to rotate it CCW (since I've obviously been tightening it all the time when rotating the nut CW) and try to see if the color of the rod surface would change indicating the previous height (I guess only the spark plugs had been changed since the 1980's as the water pump housing and the impeller looked like the original ones when replaced - that's why I would assume being able to see a slight change in the rod color caused by dirt build up etc.).

EDIT: Of course it's as possible that the lower shift rod is sitting too high at the moment since I rotated it CCW when tightening the nuts... I guess this is more likely to explain (in contradictory to the shaft sitting too low), why reverse gear is being engaged both at neutral and reverse position of the shift lever?

So probably it's wisest to try to adjust the lower part as low as it goes and then, when tightening the connection, to ensure that I'm holding the lower nut on place and rotating the upper nut only (as you already described)?
Click to expand...


I think you are right!
 
The lower rod MUST be fully turned down into the lower unit.-----Mark it so that you can see if it turns on re-assembly.-----It should stay fully seated into the lower unit !!
 
That is correct. Also make sure the shaft NEVER turns next time. This is my favorite type of shift coupling, makes plenty jobs for me to patch up. I do like them better than the older brass coupling that people usually strip out and hack them up by forcing in the cap screw when they are not lined up properly.
 
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