which is located in a position to engage the notches 47 between the teeth 45 on the bottom of each of the support bars 48 the pin 84 is bias a spring 86 into engagement with the notches 47 a pull ring 88 is provided on the end of the pin 84 to pull the pin downward out of engagement with the notches 47 when the mounting bracket 74 is to be moved to a different location on the adjustment bar the fixture 76 is one of a number of fixtures which can be interchangeably mounted on the brackets 74 the fixture 76 as shown in fig4 and 5 includes a plate 90 having a pair of pins 92 mounted on the bottom in a position to be inserted into the hollow tubes 82 provided on the mounting bracket 74 as shown in the drawing a fixture assembly 36 is mounted on each end of the adjustment bars 48 thus providing four support points on the adaptor the fixture 76 is used to support a chain 98 and includes a support rod 94 having a slot 96 at the upper end one link of the chain 98 is aligned in the slot 96 on each end of each support bar 48 to provide a sling for supporting a transmission with this arrangement the mounting brackets 74 can be moved inwardly or.