Repairing universal joint

[Ernest Christley]

Today was proof that keep parts safely tucked away until needed is a
good idea.

The Dyke Delta has a universal joint halway down the torque tube, and it
uses a big one...a MS20271-B14. One of these puppies will run you
nearly $100 bucks, brand spanking new from the likes of Aircraft Spruce.

Well, this weekend I was dinkin' around with the main gear, trying to
get everything to line up right. There's only 1/4" clearance between a
main gear pivot bolt and the universal joint. A little measurement
error, added to some triangulation error, and I'd cut that clearance
down to 1/8".

It didn't take but one gear retraction with that pivot bolt not seated
completely for the protective sheathing on the joint to get pinched.
It's not a large cut, just barely enough for the 'permanent lube' grease
to squish out. The actual mechanicals sustained no injury, whatsoever.
Is there a way to replace the rubber sheathing, or is the whole joint
toasted?

I'm actually suprised at how easily the material cut through. Sheesh,
there are materials out there that normal humans can't cut with their
pocket knives, and here is this hundred dollar part protected by
something with the consistency of well chewed bubblegum and not much
more resiliency than that.


--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

[Jim Carriere]

Ernest Christley wrote:
> Is there a way to replace the rubber sheathing, or is the whole joint
> toasted?

Have you thought of a patch for a bicycle inner tube? These bond to the
inner tube using rubber cement and normally use adhesive to hold them in
place while the cement dries. They also come in different sizes, and
you can cut them to fit with scissors too.

Don't forget to replace the grease inside the boot.

[Ron]

Hi Ernest,
Not absolutely positive I understand your request. If it regards
cutting the grease boot and repairing it, then maybe this will help.

In my really poor days I kept an old Volvo going way past its prime.
When a grease jacket on a ball joint got a crack I would repair it with
superglue, cyanoacrilate (? spelling). I would take it off, wash it
with kitchen detergent, dry it and glue the crack back together.
Worked well. I have also done this with neoprene o-rings and light duty
urethane drive belts. Seems to be about as strong as the parent
material.

Hope this helps.

Ron

Ernest Christley wrote:
> Today was proof that keep parts safely tucked away until needed is a
> good idea.
>
> The Dyke Delta has a universal joint halway down the torque tube, and it
> uses a big one...a MS20271-B14. One of these puppies will run you
> nearly $100 bucks, brand spanking new from the likes of Aircraft Spruce.
>
> Well, this weekend I was dinkin' around with the main gear, trying to
> get everything to line up right. There's only 1/4" clearance between a
> main gear pivot bolt and the universal joint. A little measurement
> error, added to some triangulation error, and I'd cut that clearance
> down to 1/8".
>
> It didn't take but one gear retraction with that pivot bolt not seated
> completely for the protective sheathing on the joint to get pinched.
> It's not a large cut, just barely enough for the 'permanent lube' grease
> to squish out. The actual mechanicals sustained no injury, whatsoever.
> Is there a way to replace the rubber sheathing, or is the whole joint
> toasted?
>
> I'm actually suprised at how easily the material cut through. Sheesh,
> there are materials out there that normal humans can't cut with their
> pocket knives, and here is this hundred dollar part protected by
> something with the consistency of well chewed bubblegum and not much
> more resiliency than that.
>
>
> --
> This is by far the hardest lesson about freedom. It goes against
> instinct, and morality, to just sit back and watch people make
> mistakes. We want to help them, which means control them and their
> decisions, but in doing so we actually hurt them (and ourselves)."