PS Magazine - TB 43-PS-596

PS, The Preventative Maintenance Monthly

ISSUE 596

JULY 2002
PS Magazine - TB 43-PS-596 - Page 8 of 32
While the TM doesn’t require safety wire on the
final drive bolts, wire does help keep the bolts in
place. It also gives operators something to look for
when checking the bolts for looseness during their
after-operation PMCS.
S
ometimes it pays to be a control
freak, mechanics. Like when you torque the
eight prop shaft screws on a Bradley or MLRS.
If you don’t do it right, those screws can vibrate loose. A
loose shaft flails around, tearing up the transmission, brake link-
age, and even the driver if it breaks through the firewall.
So take control of the situation. Check for loose prop shaft screws during
semiannual services. Never reuse loose screws ‘cause they won’t stay tight.
Replace them with new screws, NSN 5306-01-132-3369, and torque them to 86-
94 lb-ft. Use the torque wrench to tighten once, loosen and then tighten again.
Some of the screws can’t be reached with the end of the torque wrench, so
you’ll need the 4-in torque wrench adapter, NSN 5120-01-315-5708, called out in
the Special Tools appendix in your -20-1-5 TMs.
The adapter keeps the torque wrench from touching the bearing cap and other
parts. If it touches, you’ll get an incorrect reading and the screws may not stay
in place.
When you use the adapter, remember that it adds to the length of the torque
wrench. So the actual applied torque will be less than what the torque wrench dial
or scale shows.
To use the adapter correctly, you must convert the torque value before you start.
It’ll keep you from under-torquing or over-torquing the screws.
CORRECTED
READING
REQUIRED
TORQUE
VALUE
TORQUE WRENCH LENGTH
+ ADAPTER LENGTH
TORQUE WRENCH LENGTH
MLRS Carrier,
M2/M3-Series Bradleys…
Safety wire keeps
screws from moving
After
you’ve torqued
the screws properly,
keep ‘em in place with
safety wire.
PS 596
JULY 02
13
The conversion
formula is the
same for
both
the Bradley and
the MLRS…
Remember, the length of the torque wrench is measured from the center of the
handle to the center of the drive. The length of the adapter is measured from the cen-
ter of the drive to the center of the wrench.
Length of torque wrench
Length of adapter
oh, no!
shaft!
New screws
come with
holes pre-
drilled in
the heads.
596. 12-13 (C)
6/3/02
1:19 PM
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