This supplement describes the changes affecting lift chains used on Big Joe Mfg. Co. trucks. A new type lift chain (part number 402034) is being used. This chain replaces the older chains (part number 308200 or 308500). When installing the new chain on a truck originally equipped with the old style chains, an adaptor kit must be used.
The adapter kits for the 308200 chain is kit no. 904020 and for the 308500 chain is kit no. 904021. The kits include the following.

NOTE: One kit is required for each chain.
The adaptor, part number 7520 or 7521 is installed between the end of the chain and the chain dead anchor weldment as shown in figure 1. The 7520 adaptor is used between the new 402034 chain and the dead anchor 243003 on older trucks.
The 7521 adaptor is used between the new chain 402034 and the dead anchor 243001 on older trucks.
The new pin 402055 is used with the end of the adaptor mating with the chain and the old 0600303 or 060315 pin is used with the end of the adaptor mating with the chain and the old 060303 or 060315 pin is used with the end of the adaptor which mates with the dead anchor.
Table 1 indicates the serial number for each model truck when the new chain system is implemented and the adaptors will not be required.

Table 1. Serial Number Break For New Chains

Table 2 provides a cross reference of old part numbers to new part numbers.

Table 2. Cross Reference of Part Numbers

NOTE: On IBH Trucks Serial No. 312605 thru 312751 the 308200 chain was used in place of the 308200 chain. A special adaptor (part number 904015) is required between the 308500 chain and the dead anchor on the truck. The anchor bolt must be changed to part number 052753.