PS Magazine - TB 43-PS-681
PS, The Preventative Maintenance Monthly
ISSUE 681
AUGUST 2009
16
PS 681
AUG 09
17
PS 681
AUG 09
P
roper driveshaft PMCS is important! Without it, your FMTV’s driveshaft can be shafted.
Some early model FMTVs developed cracking on the rear section of the engine block.
Product improvements, such as thicker engine blocks and new design driveshafts, were
developed and used over the years to reduce cracking. But even with improvements, this
problem hasn’t completely gone away.
Here’s where you come in. Giving poor PM the shaft can help save the driveshaft and
engine.
Inadequate lubrication of the driveshaft
universal joints leads to premature wear.
Over time, vibrations in the driveline can
occur as the universal joints begin to wear
out. Left unchecked, these vibrations can
continue traveling to the rear portion of
the engine block and cause cracks near
the oil pan housing area and starter motor
mounting flange. Also, lack of lubrication
in the driveshaft’s slip joint can lead
to excessive end play in the driveshaft
universal joints.
Put a stop to this by performing all of the PMCS and required lubrication for the
driveshaft components. Refer to your FMTV’s operators and maintenance tech manuals,
and keep this in mind:
•
Operators, every 30 days, lubricate the driveshaft universal slip joint and all
universal joints with GAA grease.
•
Mechanics, every 6 months or 6,000 miles, lubricate all the driveshaft universal
joints with GAA. Then perform the driveshaft hinging inspection. No more than
0.006 inch of play is allowed. Also, perform the radial end play inspection. No more
than 0.020 inch of play is allowed.
For more info, eyeball TACOM MAM 09-018 online:
D
oes your unit have M931/M931A1/M931A2, M932/M932A1/M932A2 or
M931A1P1/M931A2P1/M932A1P1/M932A2P1 tractor trucks? If so, you might
want to make sure you can see the light. I’m talking about the
trailer
lights.
The problem is, the intervehicular (IV) receptacle connector can be installed
incorrectly. If it’s installed wrong, you won’t see the trailer lights when you should,
possibly causing rear-end collisions, injury to personnel and damage to equipment.
And the procedures in TM 9-2320-272-24-3 don’t give enough information to
prevent this from happening.
TACOM GPA 08-022 lays out
instructions for inspecting and
correcting this connection issue.
If you haven’t already, go ahead
and inspect your truck to ensure
the IV receptacle connector and
its electrical connector cover are
properly
positioned and installed.
Eyeball TACOM GPA 08-022
for more information on this. It’s
on the AEPS website:
commodity/Gpm/Tacom_
WN/08/gpm08-022.html
Don’t
FMTV…
that’s right!
PMCS is
only
truly
done if you…
Don’t
Shaft the
Driveshaft!
M931/M932 5-ton Tractors…
Can You See the
Light
?
This is behind spare tire
rack looking downward
on M931, A1 & A2 trucks
Front of
truck
Cover hinge
Make sure IV receptacle connector and
electrical cover are positioned like this
Improper lubing leads to engine block cracks
your driveshaft’s
taken care of. now
your pmcs is
done.
Key way
Don’t
look at
me, Mr.
Trailer!
Your operator should’ve made
sure you were connected right
and could see your lights
before
moving out.
681.16-17.indd
1-2
7/8/09
11:49:27 AM
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