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1965 75 hp Electramatic Lower Unit Shafts Stuck After Rebuild

jomad04

New member
I just finished rebuilding an Electramatic lower unit from a Johnson 1965 75 hp outboard (the only thing I didn't remove was the forward coil and bearing behind it because it looked and felt fine). When I put it back together and installed gearcase head with the bearing and prop shaft seal in it, the prop shaft wouldn't turn anymore. The same thing happened when I tightened the nuts on the studs holding the lower and upper part of the lower unit together. The drive shaft wouldn't turn anymore. It felt rough to begin with even before the nuts were tightened and the gears made a clanking sound. These problems were the exact reason I rebuilt it in the first place and I thought I had fixed it. Any idea what would cause these issues?

Thank you in advance.
 
How did it run for you last year ?-----It would be easy to figure this out , but I can not see / inspect the parts.
 
It was a new boat to me and I’d never seen it run. I know it probably wasn’t the best idea to buy a motor that didn’t run but it was cheap. I’ve never had a boat or worked on an outboard so I’m learning as I go. I rebuilt the powerhead (which is working great) and now I’m on to the lower unit. I can take it back apart and take pictures of the parts, just let me know which ones you need pictures of.

Thanks for your help
 
Are the forward / reverse gear assemblies in the right spot ?---The reverse gear has the roller bearing assembly on the hub.-----These electric shift units are very simple in my opinion.----
 
Yes the gear assemblies are in the right way. I looked at the diagram while reassembling it. The bearings are assembled correctly, but as I mentioned I didn't remove the forward coil or tapered roller bearing behind it because I don't have to coil puller tool. Do you think that would be worth doing?
 
My best guess is somebody removed the tapered bearing race and didn't reseat it all the way into the bore in the nose of the gearcase
 
I have the puller set for those electramatics somewhere.----Find a good machine shop or garage and see if they can pull the coil and bearing.
 
I’ve tried just about everything with this gearbox at this point but I still can’t figure out what the problem is. I replaced both the upper and lower housings the thrust bearing in the back, the forward solenoid and the drive shaft and it still gets stuck when I tighten the nuts down. Even when it’s loose I can feel the gears grinding. I noticed when I push on the upper section to the left side without the nuts tightened it turns well. It seems like the gearcase must be bent but I can’t see that it is. Does anyone know what might cause this?
 
AHA!!! Bent gearcase. I've seen several bent ones, but yours must be really badly bent. Take the upper gearcase section to a machine shop and have them check the parallelism of the machined top and bottom surfaces. They will know how to do it. Option: you can do it yourself. Instructions are in the service manual.

So how do they get bent? Take a look at the section between the torpedo and cavitation plate. See how skinny it is? Side thrust on the skeg is the culprit. Like beaching the boat and wakes or waves thrust the aft end side to side. Or an accident where a trailered boat is backed into something or rear-ended by another car. Or launching the boat in a shallow water boat ramp and the non-tilted motor jams into the lake bottom. Or take your pick of a dozen different ways.
 
Ok so I ordered a new old stock gearcase and put it together. Still doesn't work... Same problem as before. When I tighten the nuts down the drive shaft wont turn. I'm so done with this motor I'm about to scrap it. I absolutely do not understand why this would be happening. Any chance the prop shaft might be bent? I don't know if that would cause this issue but I've replaced basically everything else there is. Thanks for the help
 
I actually figured out what's causing the issue. If I leave out the reverse solenoid it turns great with no issues but once I put the reverse solenoid in both shafts get stuck. anyone know why this would happen? Not 100% sure if the solenoid is the issue but it seems to get fixed without it.
 
The reverse ELECTROMAGNET Is held in place by the 4 screws.-----So it can not be in the wrong position.----Something else is wrong I say.----Too bad you are so far away.-----I think it would be an easy fix here.
 
As I remember it, the reverse coil doesn't actually touch any rotating parts, or establish gear mesh. Something very strange going on here.
 
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