1958 35hp Johnson rde-19 drive shaft bushing

[Gipper]

Hello, I have just recently rebuilt this rde-19. New complete ignition, retro fuel pump, carb. rebuilt, waterpump, and complete gear case seal. aside from alittle fine tuning here and there, she runs like a champ. but i have noticed alittle water still getting into the gearcase after a couple of runs. pulled the the lower unit/gear case and made sure everything was on the up and up with the seals....check. did however notice that the driveshaft(top where impellar is) has a little play in it. Enough play that looks as if it can't seal properly with this much play. I am suspecting the bushing(part no. 304084) may need to be replaced. I'm not in the mood to figure out as i go so can anyone let me know of the best procedure of removal/install?

 

[fdrgator]

I believe gipper is concerned with slop in the bushing below the water pump, not the pinion bearings. Not to say there may not be problems down there also, who knows? However as to the question at hand, the bushing under the water pump should be free floating in the gearcase and come out by sticking your finger in it and pull. If it doesn't, then a slide hammer puller may be required if you don't want to take the whole thing apart.

I don't know how much slop we are talking about here, but a new seal should be able to tolerate anything reasonable. But keep in mind, once installed to the motor, the upper end of the shaft is located by the crankshaft splines and does not slop back and forth.

One final thought, the gearcase and/or exhaust housing may be bent. It only takes a few thousandths of housings bend to throw the drive shaft out of alignment with the crankshaft, which results in holding it to one side of the gearcase bushing. A few more thousandths bend, and the shaft will bend back and forth with each rotation, eventually resulting in a broken shaft. There is no way a new or tighter bushing can compensate for a bent housing. Bent housings are covered in the factory service manuals.

 

[racerone]

Correct some of those bushings are " full floating " and just slip out.--------Pressure test the gearcase to find leaks.----The O-ring on the shift rod is often overlooked as well.

 

[Gipper]

Correct some of those bushings are " full floating " and just slip out.--------Pressure test the gearcase to find leaks.----The O-ring on the shift rod is often overlooked as well.

I did figure i would have to get a special puller kit for this one. I have redone most of the motor anyway, might as well preserve the integrity of the lower unit and knock this job out as well. (racerone) I agree, the shift shaft o-ring is often overlooked or bypassed because of difficulty. I did however made a home made step punch from a phillips screw driver(o-ring housing for those who don't know) and replaced it. Thank you again gang for the quick replies!

 

[Gipper]

And the "slop" i am referring to may have some merit. the shaft has some scoring in one little section just under the impeller. Dosen't seem to be lower than that but something went wrong in the past for this to happen(foreign object or wore out parts). (fdrgator) good point on the possible warped or bent gearcase/exhaust. Not quite sure how to check for this but I will perform a pressure test to pin point a leak. And just for a point of reference on this topic....after running about 2 hrs, then going home with it and letting sit for a couple days(letting gear oil and water separate) Approx. 2 table spoons of water will drain out before oil starts to drain. Not a devastating amount, but enough to drive my OCD in the warning zone.

 

[racerone]

I replace the shift o-ring by using the factory tool or thread the bushing with a 5/16" tap.------The o-ring can also be replaced without removing the bushing.-Lots of folks will question whether that can or can not be done.---That's OK by me.

 

[Gipper]

(kimcrwbr1) yes, we can more than likely rule out bent/warped housing. skeg and housing does not have any abnormal damage. Just normal scratches and scuffs.

(racerone) Trust me...i attempted removal/install with scribes, etc... I lacked the patience and didn't want to damage the new seal with it being a first try at cutting this particular corner lol. But yes i have read of a few guys on here including you that have had success via this method.

Thanks again gang for the input. I will run a pressure test and pinpoint the leak. I will reply of the finding even if it just happens to be spaghetti seal, oring, etc...

 

[fdrgator]

(kimcrwbr1) yes, we can more than likely rule out bent/warped housing. skeg and housing does not have any abnormal damage. Just normal scratches and scuffs.

QUOTE]

You can only rule it out in your mind. I posted the information so you would be aware of the possibilities. The skeg condition is not a good indicator. The ONLY way to tell is with a surface plate and dial indicator. That requires substantial disassembly, therefor it rarely gets done except after the drive shaft breaks. Even then, people often just slap in a new shaft without checking why it broke.

 

[Gipper]

(kimcrwbr1) yes, we can more than likely rule out bent/warped housing. skeg and housing does not have any abnormal damage. Just normal scratches and scuffs.

QUOTE]

You can only rule it out in your mind. I posted the information so you would be aware of the possibilities. The skeg condition is not a good indicator. The ONLY way to tell is with a surface plate and dial indicator. That requires substantial disassembly, therefor it rarely gets done except after the drive shaft breaks. Even then, people often just slap in a new shaft without checking why it broke.

I would certainly not dismiss this good advice. If the shaft were to break(lets hope not), I certainly would not just put a new one in without questioning what caused it to do so. Is there any preliminary wear, damage, or the way it operates I should look for that would suggest a bent/warped skeg/housing. I would guess examining every bearing, bushings, gears, etc... for abnormal damage but let me know if you know what to look for without disassembly, surface plate, and dial indicator. Just out of curiosity.. in the event of drive shaft break/fail, what's the most common place that it breaks at? where ever the most friction was would be my guess but I haven't seen any epic fails as of yet from any motor i have had.

 

[fdrgator]

I ran the numbers through my computer. If a housing were bent so that the gearcase to exhaust housing had .010" gap on one side, and assuming the shaft is 2' long (for convenience), then the upper end of the shaft would be .080" off-target. That's a little shy of 3/32".

So......unless you have a seriously bent housing, I doubt that is your problem.

Back to what I said earlier, the top end of the shaft cannot slop back and forth when installed because it is being held by the crankshaft. The seal should be able to stand what little bit of off-centerness there may be in the shaft.

 

[Gipper]

I ran the numbers through my computer. If a housing were bent so that the gearcase to exhaust housing had .010" gap on one side, and assuming the shaft is 2' long (for convenience), then the upper end of the shaft would be .080" off-target. That's a little shy of 3/32".

So......unless you have a seriously bent housing, I doubt that is your problem.

Back to what I said earlier, the top end of the shaft cannot slop back and forth when installed because it is being held by the crankshaft. The seal should be able to stand what little bit of off-centerness there may be in the shaft.

thank you and everyone for shedding some light on this topic. when i did the impeller and gear case seal overhaul, I had no issues with reassembly and everything mated up just fine. (fdrgator) Makes perfect sense that much of any play will be eliminated once connected to the crankshaft. As far as the little water that got in, I'll be pressure testing soon and will blow some bubbles somewhere. THANKS AGAIN ALL!