Situation
1. This month three MLVW have experienced failure of the trunion. These were:
- 2 PPCLI (Shilo) - traveling at low speed (approx 10 km/hr) in a compound
- 26 Fd Regt (Shilo) - traveling at low speed (approx 15 km/hr) on Base
- unit not stated (Saint John) - details TBC from LFAA
2. The occurrence at 2 PPCLI was initially considered a one time fault, but within a two week time frame a second incident occurred at 26 Field Regt. The incident in St John occurred this past weekend.
3. I have queried all LFAs and LFDTS on my net. Only reports thus far of failures are from LFWA and LFAA.
Discussion
4. In all cases the trunion sheared off breaking flush with the housing. No accident or injury occurred as a result of the two incidents in LFWA. I don't have any details regarding the incident in LFAA yet but no mention of accident or injury in the initial report. In each case the driver was able to retain control of the vehicle. The nature of the failure is such that there appears to be no danger of a secondary effect (nothing actually hits the ground; the axle will remain straight, etc).
5. DGLEPM has been engaged and is investigating/assessing a way forward. Thus far the information available is:
- Other than one other incident of a failure in Wainwright 2 - 3 years ago attributed to 'extreme off road use', there is no previous knowledge of failures of this type. Trunions don't typically fail unless there is misuse/extreme use and this does not appear to be the case in these instances.
- The cause is suspected to be age/metal fatigue. The pictures thus far recv indicate the trunions had been cracking for sometime and that the incidents occurred when the remaining intact portion failed.
- Thus far there is no inspection process identified for this nature of failure. Given the point of failure the only obvious manner of inspection is to disassemble almost the entire rear suspension.
- There are 37 trunions in national stock. DGLEPM has restricted them (QD msg reqr to order) so that we can maintain control of them as needed.
- Best estimate for the time to replace the trunion on a vehicle is 24 man hours.
6. A few pictures are attached for reference.
<< File: DSC03363.JPG >> << File: DSCN0171.jpg >> << File: DSC03364.JPG >> << File: DSC03368.JPG >>
7. DGLEPM has not recommended any restrictions on the fleet as this failure, although major in appearance, has not impacted any of the primary safety features of the vehicle (brakes or steering). However as a result of the two incidents experienced in LFWA, Comd LFWA has placed restrictions on his fleet.
8. While the incidents to date have resulted in "safe" failures in which the driver was able to retain control of the vehicle there is a level of risk involved. Although there does not appear to be any concern from a strictly technical point of view that a failure will result in loss of control, I believe there is a risk that the driver's potential reaction to the failure could result in an accident. With winter upon us I believe the potential exists for an accident on icy roads particularly at higher speeds if the driver needs to adjust for a sudden weight shift of the vehicle and then hits a slippery section of the road which could result in loss of control and an accident.
Recommendation
8. Recommend the following restrictions be placed upon the MLVW fleet:
- MLVW will not be used for troop lift
- MLVW will not be used for ammunition transportation
- MLVW are not to be used on highways
- the fleet is restricted to a maximum speed of 60 km/hr
9. A caution be included (previously communicated on my net) that that personnel working under MLVWs are to support the body under the box when using jack stands in case the trunions breaks while working on or adjusting the rear brakes. The rear suspension should be left free floating and not supported. It is highly recommended that a Veh Tech be present when doing so.
10. Any further failures of this nature to be reported to Army G4 Maint ASAP.
Way Forward
11. DGLEPM/the LCMM will continue to work with QETE to inspect the failed parts to improve their understanding of the cause of the failure. Also they will continue to assess the feasibility of a practical inspection method to identify vehicles at risk for this type of failure. If the current belief that is an age related issue holds true then we are likely looking at these restrictions remaining in place until MSVS (MilCOTS and SMP) are fully fielded and the MLVW fleet retired, unless an inspection process can be developed.
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What get me... I looked up one of the CFRs of the MLVW that failed and it was a TRK MLVW KITCHEN SEV W/W. Meaning that truck does alot of sitting (not moving). IMO we shouldn't be putting an blanket on the hole fleet with out looking the service records and vehicle useage on the one's that failed first.
Rob
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