Prop Shaft Runout Limits

[bankney49]

Hi Guys,<br /><br />I'm running a SS prop on my 90HP Evinrude 90ETCLCD and managed to find a rock. The prop shop fixed my prop ok but they tell me the prop shaft runout is .020 . Is this too much and can it be straightened ? Our local dealer tells me a new shaft is $600.00....ouch.<br />Any insight appreciated.<br /><br />Thanks,<br /><br />Barry

 

[R.Johnson]

Re: Prop Shaft Runout Limits

.020 is to much, and yes it can be straightened. Most machine shops can do this. This is a common practice.

 

[bankney49]

Re: Prop Shaft Runout Limits

Thanks R.Johnson....would you happen to know what is acceptable as far as runout is concerned ?<br /><br /><br /> Barry

 

[R.Johnson]

Re: Prop Shaft Runout Limits

I'm not sure if the service manual gives that figure. A machine shop should have no trouble with that .020 figure. When I get out to the shop, I'll see if I can find it, but they should have no trouble bringing it back close to zero.

 

[R.Johnson]

Re: Prop Shaft Runout Limits

Unless it's in a service bulletin, I can't find it in the manual. They would probably recommend replacement.

 

[wilde1j]

Re: Prop Shaft Runout Limits

0.003 to 0.005" is the absolute max depending on the motor. Any good shop will have prop shafts straighten, rather than replaced. Perfectly acceptable fix.

 

[bankney49]

Re: Prop Shaft Runout Limits

Thanks fellas...I took it out myself and dropped it off at a local shop...he straightened it to .002. As soon as I get the case back from some minor cosmetic surgery I'll be able to reassembly and get back on the water. <br /> Thanks again for the insight.<br /><br /> Barry

 

[Marc J.]

Re: Prop Shaft Runout Limits

Barry, I'm in the same situation, same motor. I've been reading in my OMC manual, but I've yet to tear into it. Anything you have learned would be appreciated. Post back here or email me at Marc930@aol.com. Thanks in advance.

 

[bankney49]

Re: Prop Shaft Runout Limits

Hiya 73Baja,<br /><br /> I just followed my manual...and improvised a bit...The bearing housing had two 5/16 pre-tapped bolt holes so after removing the 4 inner bolts I just used some 5/16 redi-rod and steering wheel puller to pull out the bearing housing.<br /> The big snaprings inside required a very large set of sanpring pliers to get these out.<br /> The only other tricky part was removing the pinion gear nut. I didn't have the proper tool for holding the driveshaft so I used a pair of visegrip chain style pliers around the middle of the shaft and a 7/8 open end wrench inside the gear housing padded with a rag so as not to damage the inner machining. <br /> Once the nut is free and the water pump housing and driveshaft seal housing is loose, I smacked the visegrips with a hammer to release the taper fit between the diveshaft and pinion gear.<br /> Then it was a matter of holding your mouth funny and fiddling to get the pinion gear out...I think we fiddled until it slide to the bottom of the housing before it would come out. There might of been bit of cussing invloved too.<br /> I have ordered some new seals for reassembly so I won't know how that part of this project goes until then.<br /><br /> Good luck,<br /><br /> Barry

 

[Marc J.]

Re: Prop Shaft Runout Limits

How's it coming Barry? I found a couple of local machine shops experienced in the art of propshaft straightening, but I haven't got around to taking it apart yet. EVERY boat shop around said it couldn't be straightened, I shouldn't try it myself, and I would definitely need a NEW propshaft. I hope we both prove them wrong.

 

[rodbolt]

Re: Prop Shaft Runout Limits

the problem with straighnening most larger HP shafts is most are a two part friction welded shaft. the part outside has to be durable and not rust. the parts inside have to be machinable and they will rust rapidly in water. if its bent at the weld line it can crack and fail. that being said I have seen a few straightened with decent success. most drive shafts and prop shafts are built this way on larger HP engines. the metalurgical requirements for the shiney parts inside are vastly different from the shiney parts outside.<br /> the big problems I have with the backyard methods of pipe wrench/vise grip removal method is 1 its hard to properly torque the NEW pinion nut,2 it leaves gouges that can turn into stress fractures leading to shaft failure and 3 the tool is only 30 dollars or so and can also be made by cutting the splined end from a junk v4 v6 crank and welding a socket to it.

 

[Marc J.]

Re: Prop Shaft Runout Limits

Thanks for sharing that Rodbolt. Be glad I don't live closer, I'd be trying to use your shop and tools.

 

[rodbolt]

Re: Prop Shaft Runout Limits

I used to run a friction welding machine in fort worth occasionally. we did drill stem tubing and cutter heads. dont know who figgued it out but its cool. heat both ends cherry red. turn one clockwise about 550 RPM and the other counter clockwise slighly slower in a clutched chuck and slam them together until the clutch slipped. if all is well its a seamless weld. I sold most of mine in the past years and hope to retire this year . bout all I got left is my electrical test and hand tools. plus my trusty oxy rig .