NEWS | March 4, 2021

HIMAR: Frame Rail Check


This article initially appeared in PS 789 (Aug 18), p. 38-39. 
                       
The HIMARS chassis’ TM 9-2320-450-13&P in IETM EM0259 (Sep 16) has an error in Step 11 of the Weekly PMCS. This is the correct criteria for frame rail damage:
 
 
Frame Rail Inspection Correction

Bend Evaluation
 
1. Put a straight edge against the bottom of the frame rail.
 
Bend Evaluation
Bend evaluation with straight edge
2. Measure damage depth at the widest point.
 
2.	Measure damage
Measure damage
 
3. Look for cracks, tears, sharp bends or flattened areas that indicate metal-to-metal contact. 
 
4. Use this criteria: 
 
  • under 12mm, no restriction.
  • 12-30mm, monitor and inspect after operations.
  • 30-40mm, no off-road driving and contact AMCOM LAR.
  • 41mm or greater, deadline vehicle and contact LAR for depot repair of frame rails.     
For any launchers with bent frame rails with damage over 30mm, inspect motor mounts and bump stops. *Check leaf springs around U-bolts and mounting brackets. Also check leaf springs for cracks. Check spring and cab latch mounting bracket for damage or cracking.*
 
 Inspect for damage or cracking
Inspect for damage or cracking
 
Don’t forget to perform the shock inspection like it says in the after operation PMCS in TM 9-2320-450-13&P.

Replace shocks that show any signs of damage following the instructions in the TM. Make sure the front shocks have been changed within the last two years.
 
Replace damaged shocks
Replace damaged shocks

Good shocks help prevent bent frame rails.

Check shocks after operations and replace every 2 years
 
**Also, don’t forget to check motor mounts for cracks and damage. Pay attention to the front ones as they get abused if the frame rails are damaged.**

This correction will be made in the next change to TM 9-2320-450-13&P.
Note: The sentences that appear between * and ** are changes or additions to the original article.