PS Magazine - TB 43-PS-714
PS, The Preventative Maintenance Monthly
ISSUE 714
MAY 2012
25
PS 714
MAY 12
Dear Sergeant Blade,
As Chinook mechanics, we often work on the No. 1 aft synchronization
(sync) shaft forward end. It is located behind the combining transmission in
the ramp area and it’s not easy to access. We use a stepladder to get to
the shaft and the workspace is real tight. The remove and install procedures
are in WP M01079 and M01088.
The tools required to work on the shaft consist of a ratchet wrench to
hold the bolt from the front, an extension and a deep well socket to turn the
nut. The problem is, the ratchet with the extension is too close to the aft
synchronization shaft. That is too close for comfort because if the ratchet
and extension slip off the nut and hit the shaft, the result could be nicks,
scratches or gouges on the aft sync shaft. Then we have to replace a
damaged shaft to prevent drive shaft failure or an imbalance that can lead
to excess shaft vibration.
We’ve come up with a sync shaft support tool that we place over the
shaft. It allows us to turn the nut while the ratchet and extension rest on
the support. If it slips off while we are cranking, the wooden shaft support
takes the hit and not the shaft itself.
The tool is simple to make using common hand tools and hardware. The
tool is made from a 2” x 6” piece of wood cut to fit over the synchroniza-
tion shaft and sits on the airframe sync shaft support. We notch it so that
it fits around the shaft. Then we use metal strips on each side of the top
edge to prevent the wood from splitting or getting damaged while using the
ratchet. The metal strips are attached using four bolts and four nuts.
To make the wooden shaft support, use the dimensions below.
R2 7/8”
9”
1
13
/
16”
1
1
/
2”
Notch
to f
it
Notch
to f
it
1”
1”
1/2”
R3/16”
4
7
/
8”
3”
3”
4”
11”
R3/16”
R3/16”
R3/16”
3
9
/
16”
3
1
/
4”
2”
3
/
8”
3”
3”
4”
11”
3
/
8”
3
/
8”
3
/
8”
1”
3
/
8”
3”
3”
4”
11”
3
/
8”
3
/
8”
3
/
8”
CH-47D/F.…
Shaft Tool
Prevents
Damage!
Main Body
Mid-Plate (2 each)
Outer Plate (2 each)
2”x 6” (Wood)
0.050 (Metal)
0.090 (Metal)
what
might
happen when you
work on the sync shaft…
what
will
happen when you
work on the sync shaft with
a homemade support tool!
ThE sync shaft support
tool will make your
work
safer
and
easier!
714 24-25.indd
1-2
4/2/12
5:30 PM
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