17-4PH Stainless Swivel Shaft Mod

[SomeSailor]

I'm doing some winter maintenance and one of my "To Do's" is to fix a annoying little "seep" I've had for the last year or so on my boat.

One of the things I'm doing is replacing the carbon steel upper swivel shaft with an after market one from a guy named Ron Bender at www.JRMarine.com (http://www.JRMarine.com).

He sells a stainless replacement for the OEM shaft'

Anyhow... it's a pretty cool looking part.

Here are a few pics:

17-4PH aftermarket stainless swivel shaft (no hole)

http://www.iboatnw.com/gallery/d/7555-2/008+_853x1280_.jpg

A few minutes on the mill:

http://www.iboatnw.com/gallery/d/7575-3/014+_853x1280_.jpg

And presto! A GREASABLE stainless swivel shaft. :)

http://www.iboatnw.com/gallery/d/7610-2/029+_1280x853_.jpg

http://www.iboatnw.com/gallery/d/7630-3/038+_853x1280_.jpg

I know... just a piece of metal... (unless you like cool metal stuff & shavings) :)

[Tedster]

If you made that I am impressed big time!

[SomeSailor]

Pretty cool looking huh?

Now if it stops my annoying leak. What a pain it is... MAYBE a half gallon over the two weeks we were out this summer... but definitely seeping in.

This'll fix it though. Besides... new U-joints, gimbal bearing and rubber was due.

[Go Aweigh2452]

looks great Mike... nice work...:argh2

[Nehalennia]

Drilling, machining, milling stainless is not fun.
Looks like you did a nice job on the modification.

[SomeSailor]

I broke down and bought a really nice set of cobalt bits which really makes it possible to drill that hard stuff. Ya just gotta keep the speed down and the feed steady and it'll spin off ribbons perfectly. It's a cheap mill, but fun to use.

[Willapa Trophy]

I have an old Jet mill and an old metal lathe that swings about 10"s, I cannot begin to think of the number of times that they have saved my bacon at 1:00 am, or kept me amussed making some trinket. Nice piece Mike.

[pkrogh]

I missed this thread.......
But I'm dying to know......

What swivels on it???

Pete

[SomeSailor]

Hey there Pete.

The whole outdrive swivels on those two pins. The upper is much more substantial than the lower and these two pins and the hydraulic rams are what push the boat through the water.

[pkrogh]

Ahhhh! I had never seen what the pins look like in the Merc. drive.

I like what you did for getting the grease in there. I still have a couple of places on my VP drive to make similar
modifications.

I just can't stand the idea of not being able to put grease in the 'joints'!

What kinda mill do you have?

Pete

[Nehalennia]

Mike did you attach a zerc to the top hole? If so, can you even get to that and grease it? I'm having a little bit of trouble visualizing it.

[SomeSailor]

Actually... I was torn between a top zirk, or a rear facing position. I decided on the rear facing and drilled it... then needed to drill a journal upwards to meet that one. The drill broke through and I ended up with a top hole also. :)

So I tapped them both and now need to decode which to use (really don't need two) :)

[Nehalennia]

Did you take more pics?

[SomeSailor]

Yeah. I just need to get some time to upload them. :)

Started milling the cover plate last night.

[Nehalennia]

Alright. just curious to see it up close.

[SomeSailor]

If curious, just swing by and take a look. I'll be drilling and installing a cover plate tomorrow.

It's just a small rectangular window into the tiller arm area that is pretty obvious without the cover. :)

[fishaman]

Just wanted to add to the thread so that it all will be in one place.
I have the same leak, and got the same stainless shaft as Mike. It arrived somewhat ready to install, with a couple of modifications:

1 ) Badly needed polishing in the seal area, it looks like they did not do proper finish after machining. Screwing a stud in the threaded hole allowed to put it in my drill press and mirror polish the lower cylinder.
2) The edges of the cylinder were sharp enough to guarantee the rubber damage when the shaft is pushed through the seal. Smoothed with a small file.
3) The back of threaded hole was jam packed with stainless spiral chips from thread cutting. Took them out with a small screwdriver.

I am not as brave as Mike, so no stainless drilling for me... I have found a discussion of the same issue on iBoats, and I like their suggested solution. I will drill a hole through the gimbal housing and the lower bushing as shown in the picture, and install the grease fitting. Not sure if I will drill the upper hole which was standard on the earlier models, usually the upper bushing is not a problem.

Still thinking of possible improvements to the shaft, like adding a groove to the cylinder to better spread the pumped grease. My first car had pins and bushings instead of ball joints in front suspension, and all of them had those grooves.

I have all parts to complete the job (Thanks Eric!), and I will attempt to do it this weekend by completely removing the gimbal housing, it's easy to do while my engine is out. Will post some pictures later.

[SomeSailor]

I'd really recommend taking the time to drill the shaft. It went pretty easily. Just buy a nice new .25" cobalt bit and a smaller .125" cobalt bit and put it in the press and press slow and with authority. It went pretty quickly actually.

It works great too. I can pump grease right into both bushings and see it exit under the swivel shaft seal. Reassuring if nothing else.

[fishaman]

Mike,
Thanks for the encouragement, I might give it a try today. Did you drill the channel orthogonal to the shaft all the way through the lower cylinder so that there are two openings delivering grease to the oppozite sides of the lower bushing?
As I understand it, you have plugged the lower end of your shaft, so the grease is pumped to the chamber above the upper bushing, then goes through the drilled channel to the lower bushing. If it is correct, does some grease escape through the upper bushing to the steering arm opening inside the bilge? I believe earlier models had a seal to prevent it.

[SomeSailor]

Drill down through the shaft far enough to reach the midpoint. Then drill the intersecting journal from the side. I only drilled from one side. I thought at first I may have drilled too deep, but after cleaning the shavings out I realized I got lucky. To do it over I wouldn't go so far down (probably just to below where the seal starts).

Its really simple though and worked great.

[fishaman]

What the doctor said...

http://photos.scaneffects.com/images/A_1/2/5/0/120521/0ad861005d0d4d3a93f70ec429402804.JPG

http://photos.scaneffects.com/images/A_1/2/5/0/120521/1c97bf3efeba4b7a96f561417c729489.JPG

After drilling 0.25" hole down, I decided to drill two 0.125" opposing exit channels: one in the middle to get the grease closer to the seal, and one a little higher, approximately at the bushing midpoint. Drilling was easy, but the bits get dull fast. At first it's all easy and nice, but after about 5 seconds it starts screeching and stalling, and overall progress slows down.

Thanks to Mike's encouragement I feel much better about my shaft's "greasability" now!

[SomeSailor]

Very cool. I need to get a plate cut for you too. You still need on yes?

[fishaman]

I will be removing my gimbal assembly tomorrow, hopefully it will come off without problems. My first attempt will be to replace the pin without cutting, if it fails, I might take you up on it. Thanks for all the help, I really appreciate it.

[SomeSailor]

If you have the transom assembly off you can do it without cutting.