Old GB32 steering mechanism question

[Tazling]

Me again, sorry for the pepper-shot of questions but I am just getting to know my "new old boat" and discovering many mysteries and fixit items.

I noticed that there was a lot of deadzone/slop in the flybridge wheel but none at the wheelhouse steering station. Thought maybe a keyway on the wheel shaft was bad but no, everything is turning properly if you look inside the upstairs console (what a barn it is, too -- nice to be able to crawl right in there so easily).

So I peeked behind the instrument panel downstairs and found a second big square metal (bronze??) box presumably with gears in it. The slop is here, in the vertical shaft that transmits the upstair steering action to downstairs and vice versa. I see that there's a collar and bolt or machine screw that couples the vertical shaft to the (gear?)box here, and I would bet good money that this bolt goes into a divot or bliind hole in the vertical shaft, and that this hole is now egged out, allowing the bolt end to "rattle" sideways in it, accounting for the 15 degrees or worse of deadzone in the steering up top.

So far so good, but disassembling this mechanism looks hairy. There's an autopilot ganged onto it via bike chain and it looks like a big operation (not zero risk either) to free the vertical shaft.

If anyone else has had this issue and fixed it, I would be interested to know how you went about it. I have been thinking about backing the bolt right out and trying to fill the shaft locating hole with something robust like RTV or even JB weld, then screwing the bolt back in and letting it "set" a while in hope of filling in the egged out area. But that's a bodge job and if I contaminate the threads then it might become impossible ever to disassemble it again.

Alternatively with great care it might be possible to drill it out oversize and use a bigger bolt, but the idea of trying to freehand drill a greasy bronze cylinder inside a crowded electrical panel gives me the heebie jeebies.

Any thoughts, creative ideas, etc are welcome. The boat's usable as-is, but the slop up top is annoying and adds seconds to any change of course.

 

[Hyperion]

Is your lower steering not connected to the upper via two cables?

 

[Tazling]

steering connection

It's something like this: upstairs (flybridge) there's a wheel, which drives a short shaft which goes into a right-angle gearcase (almost cubical metal box) which translates the horizontal-axis rotation into vertical-axis rotation. The vertical shaft goes down through a stainless pillar/tube into the wheelhouse console, where it enters a very similar gear case. From the after face of this gear case comes the shaft for the wheelhouse wheel.

On this shaft, what looks like motorcycle chain, attached to two cables which go below (engine compartment) and eventually, through turning blocks etc, to the rudder quadrant (I haven't crawled back that far, but that has to be their destination). Also on this shaft, a smaller bicycle chain going to the autopilot.

So the slop is in the bottom fitting of the vertical shaft going up to the flybridge. It terminates in a sleeve which goes into the gearcase. The sleeve is drilled and there is a bolt through it going into the shaft, to lock the two together. Locking screw basically. I think the hole the locking screw goes into is egged because the shaft (and upstairs wheel) can be rotated a few degrees back and forth without rotating the sleeve and hence the lower gearbox mechanism and hence the motorcycle chain sprocket. So the upper wheel can turn about 10-15 degrees without actually moving the rudder.

I hope that's a little more clear? Sorry I don't know all the official Grand Banks factory names for these parts. Only had the boat a short time, have driven it twice, still poking around and wondering "OMG what have I done".

 

[Hyperion]

It is. I did not know this system existed on GBs. Both of mine had chain to cable from below to quadrant. Cable from drum to drum from below to fly bridge. Sorry I can't be of more assistance.

 

[Tazling]

It is. I did not know this system existed on GBs. Both of mine had chain to cable from below to quadrant. Cable from drum to drum from below to fly bridge. Sorry I can't be of more assistance.

Well thanks for taking an interest -- my GB32 is 1969 so it may have some very oldskool mechanisms. I know it has some absolutely lovely custom bronze castings and fittings

 

[Bmarler]

That actually sounds like a nice setup as long as everything is in good condition. There are a couple of things that come to mind. You have opportunity for slop in both connections to the vertical shaft. Up top there’s a connection as well as down below. If there’s slop in both connections the play is compounded. If I understand your setup correctly you have some sort of solid coupler (or hollow input shaft) on the gearboxes, and a slip fit vertical shaft with some sort of pin or bolt to connect them.
It’s possible you have the wrong item in the pin hole, or Ike you say, it’s egged out.
Sometimes, there will be a taper pin, or roll pin. Some people will replace those with a screw or something easier to get in and out. If you can remove the pin you can use the smooth ends of drill bits to measure the holes to see if they’re the same size on both sides. If they’re different you probably need a taper pin. If you want to see the end of the shaft you may be able to remove the bolts that hold the helm to the console and gain enough clearance to free it.
A picture of the gearbox/connection will help us to understand the situation better.

 

[Hyperion]

Well thanks for taking an interest -- my GB32 is 1969 so it may have some very oldskool mechanisms. I know it has some absolutely lovely custom bronze castings and fittings

Both of mine have been 1973 so I'm not that far off in the "old" department. Even my rub rails are bronze.:lol:

 

[Old Sea Dog]

Another with bronze rubrails. '79 36 with chain on sprockets going to cable. However, my quadrant needs a little attention. Thinking of flipping it over.
Yes, rebuilding the rudder table too!

 

[Tazling]

Hi all, sorry for delay, I've had a brutal 4 day haulout plus food poisoning plus engine drama... just grabbed a moment to take a couple of pics today while fighting with the FL120.

I have no idea what the little glass bulb thingie is on the right of this pic. Some kind of pressurised greasing system? This is the lower box, behind the console. There's a similar but simpler one up top on the fly bridge.

The big motorcycle chain goes below to a pair of cables which in turn do a 90 around sheaves and run aft to the steering mechanism somewhere far, far away. The smaller bike chain goes to the Cetek/Benmar autopilot (a great autopilot btw).

Now as to the vertical shaft

It looks like some PO has perhaps been fighting this same problem (slop here between the outer sleeve and the shaft) and has drilled both and put SS bolts through? If the collar is bronze that may have been a capital error (bronze being softer than SS, especially nasty sharp threaded SS).

Looks like swarf on top of the box (camera picks it up more brightly than the naked eye, it might just be dust, I need to get in there and carefully clean it up).

So that's the setup and what happens is, if I turn the lower helm the outer collar moves first, then after a few degrees the shaft starts to turn. So it seems like both those bolts have egged either the collar or the shaft or both. I could just redrill and get bigger bolts I guess. Or if it is the collar only that is egged, maybe helicoils or even steel bushings to resist the abrasion?

 

[Pete Meisinger]

I doubt if it is the stainless shaft which shows wear, more likely the softer collar. You should be able to re bore it.

pete

 

[Bmarler]

looking at the setup, and reading the symptoms you write, the issue sounds like it's in the top hole. obviously there is some egging (wear) or the thing wasn't done right to begin with. if the shaft was intended to have a taper pin and someone put a straight bolt through it you'd have that situation.
i don't think i'd go crazy doing the fix, just get a new sharp drill that closely matches a pin or bolt shank size and oversize it a bit. i wouldn't go too big though, try to keep the hole size as small as possible. maybe even metric if it's closer.

 

[DennisB1]

It appears that someone used a bolt and the threads are engaging the outer hub and maybe the shaft. Make sure that there are no threads in the load path. As suggested earlier a taper pin would be a better solution. You would need to obtain a taper ream to clean up the hole in the shaft and hub.

 

[Bmarler]

Oh yeah, the little bulb thing is indeed a lubricator.

 

[Tazling]

Oh yeah, the little bulb thing is indeed a lubricator.

Forgive my massive ignorance but what the heck does it do? and how do I use it?

 

[Bmarler]

Forgive my massive ignorance but what the heck does it do? and how do I use it?

it's actually called a single point lubricator. usually there's a grease fitting on the base that you pump grease in with a grease gun. the spring mechanism pushes a steady supply over time.
look here: https://www.machinerylubrication.com/Read/342/single-point-lubricators

 

[Forty_Two]

My 1969 GB42CL #74 has the same gearbox but i can confirm there is no play in that collar on mine.


Interestingly mine has S/S bolts exactly as yours. Do also check the locking allen keys on the chain cog wheel for the steering wires. They can back out & force the chain to slip by holding it off the cog wheel.


I have taken the upper gearbox out, it's heavy! That was because the steering wheel shaft could slide in & out of the gearbox by 1.5" due to a missing locking screw. I'll post a thread with pics in the autumn.

 

[ronobrien]

I have the cable on drum to drum setup on my 1973 GB36. I am changing the entire steering to hydraulic. If you have any interest in the parts I am removing let me know.