In the OOSC, Vehicle section 4 b. Universal Joint, a Bearing Assembly Cap is illustrated. This cap is a vital component to the universal joint and is listed as a violation/out of service under (2) only if missing or in (3) the bolts are loose. When this component is broken, there is no violation of out of service that applies since this is a 396.3(a)(1) violation.

I stopped a Mack straight truck and found the Bearing cap plate on the universal joint for axle 2 cracked completely across the plate. At the time of inspection, neither plate bolt or the 2 plate halves were loose by hand. The FMCSR's do not regulate the universal joint components and the Out of Service Criteria does not address this bearing cap plate when broken.

This bearing assembly cap (plate) is a vital component to the universal joint, and I believe that a broken cap (plate) is an imminent hazard since failure of this cap (plate) could lead to failure of the universal bearing and ultimately the universal joint. This cap serves a similar function to the bearing strap as they both keep the bearing cap barrel secure in its position. The bearing cap plate secures the bearing cap in a sleeve and the bearing strap secures the bearing cap in a half circle housing of the yoke. Both can be seen in the attached photos. The out of service criteria vehicle section 4 b. 3 states that any missing, broken or loose universal bearing cap bolt, bearing strap or retainer bolt is an out of service condition citing 396.3(a)(1). This would mean that a violation here is not a violation until it meets the OOSC. Since 4 b. 1-4 do not mention a broken bearing assembly cap (plate) the condition I was presented with was a no violation.

Given that the Bearing assembly cap (plate) and the bearing strap both serve a similar function to prevent failure of the universal joint, I recommend making a change to 4 b. 3 to include "Bearing Assembly cap". I present the following change to 4 b. (3) Any missing, broken or loose universal joint bearing cap bolt, bearing strap, bearing assembly cap or retainer bolt. 396.3(a)(1)

This would allow a broken bearing assembly cap as seen in the photos to be listed as a violation and placed out of service.

Louisville Meeting - The committee received feedback from one OEM indicating if the crack is all the way through, then the vehicle should be placed OOS. The crack essentially opens a channel that would allow for material ingress. Discussion in committee was that even with the cover cracked, there wouldn’t be any material ingress due to the solid piece of metal below the cap. Further contact will be made with Spicer for a second opinion as they are the premier supplier.

Montana Meeting - The issue was discussed with OEMs who were split and vague about this issue. The suggestion based on feedback from the industry, was that if the bearing cap was missing the vehicle would already be placed OOS. In the example provided, the parts are present so an OOS would not result, just a violation. Which at this time cannot be cited for driveline, unless it is out of service based on lack of regulation. Since there was nothing further for this specific incident, no further action was needed to be taken.