Currently there is a shortage, as in none available, of PACCAR DEF gauges for Peterbilt, and KW trucks. DEF is diesel exhaust fluid, which is required in newer diesel trucks. The gauge reports to the computer on the amount of DEF in the tank. As the DEF level falls, computer slows engine down , finally to an almost stop, rendering the engine useless. This means trucking companies, both large and small are having to park trucks worth a half million, because they can't get a $500 replacement part. To me $500 seems a little steep for amounts to a fuel level sensor. According to what I read, about 25% of their trucks are effected by this faulty level sensor. Wait times for new sensors are over 3 months now. And you thought a GE refridgerator was bad. Remember when these trucks are parked, their owners aren't getting any income, but the payments are still due. Wouldn't be surprised to see a Class Action Lawsuit over this