Air conditioning belt tensioning pulley with new bearing. This adjustable bracket and pulley was used on all 1970-73 351 engines that came with A/C, as well as 1970 428CJ & 1971 429CJ. This part often has a casting number of D0AA-8A617-C1 but not always. This adjustable idler pulley is identified by having the large bearing pulley. Same as the C8AZ-8678-A adjustable idler pulley only with a small bearing pulley.
We also offer a bearing replacement service to rebuild your adjustable idler pulley, see item 27539.
Ford part # D0AZ-8678-C and D0AA-8A617-C or D0AA-8A617-C1
*Note* All new bearings will have a slight bit of play in them. This is by design, by the manufactures. We have asked the suppliers, and the answer is to allow for possible heat expansion. Even the "Koyo" branded ones, which were used starting in 1968, now have an ever so slight amount of play.
*NOTE* If concours correctness is not a concern, we offer used Ford
service replacement air conditioning belt tensioning pulleys, these are
in every way the same as the D0AA-8A617-C1 bracket and pulley. Same
large bearing, but carries a casting number that starts out D5..., or
D8...
Check out this video