TN26 5hp Johnson upper crankshaft seal replacement

[Woodruff]

I downloaded a parts catalog for the TN models and cannot locate the upper crankshaft seal part number. This is the seal under the armature plate. I have yet to remove the armature plate so I haven't inspected that area but I can hear crankcase pressure leaking from under the plate. Does anyone have the part number for the replacement seal? I can't imagine not having a seal in this location.

 

[racerone]

I am rebuilding a 1959 model 5.5 HP.----There is no runner lipped seal on the top of crankshaft.-----It has a slinger.------Upper bushing might be worn on your motor.

 

[F_R]

The slinger system was used on thousands upon thousands of motors up through at least 12 hp. Any oil that does leak up past the bearing is thrown off by the slinger and then sucked back down through special channels to the intake manifold for recirculation and burning. The simple system has worked for many years.

 

[racerone]

So simple indeed.-----No reed valves on them either to make noise and get stuck open.

 

[Woodruff]

I suspect that the upper bushing is most likely dry as this motor probably hasn't ran for 20yrs. Perhaps a bit of oil will seal off some of that crankcase pressure. There is no play in the upper end of the crankshaft that I can detect.

 

[Crosbyman]

see info on slinger on a CD

 

[Woodruff]

Great information here! I wasn't looking forward to replacing a top crankshaft seal and now I have a complete understanding of the slinger and bearing lubrication surfaces. Thank you for the documents!!

 

[Crosbyman]

info is from the Johnson manual which you should get a copy to service your oldy (oldies)