BB-7063, 4-speed pilot bearing spacer
Posted: November 5th, 2018, 7:41 pm
I am hoping that the club's 4-speed overhaul expert or historian can explain to me why Ford made this particular spacer out of round wire instead of as a machined part with a cross-section that has parallel surfaces or as a "D" shaped spacer made from slightly harder material or perhaps bearing bronze.
I have searched for a NOS BB-7063 for a long time without success. I have disassembled three 4-speed transmissions and all three are worn and have flat spots on one side which changes the original round cross-section into more of a "D" shaped cross-section. More importantly, this reduces the amount of spacing by the amount of lost material. A worn spacer changes the relationship between the BB-7017 Main drive gear, BB-7120 pilot bearing, and the BB-7061 Main shaft, and may lead to the transmission popping out of 4th gear under a load.
I could machine new spacers from scratch with either parallel faces or as a "D" shape with original thickness from the flat to the far side of the round. All of the wear is always on only one face, so why can't I just make a new spacer to original thickness with a "D" shaped cross section and place the round face as the wear surface? Has anyone ever done this? Is there a Ford engineering reason why the spacer must be round on both faces? Do you think Ford made it round like a "bull ring" just for cost reasons, or is the round cross-section key to lubrication flow and reduced contact area? Could both faces be parallel? An original Ford BB-7063 measures: OD=1.100, ID=.8125. wire diameter is .144
I have searched for a NOS BB-7063 for a long time without success. I have disassembled three 4-speed transmissions and all three are worn and have flat spots on one side which changes the original round cross-section into more of a "D" shaped cross-section. More importantly, this reduces the amount of spacing by the amount of lost material. A worn spacer changes the relationship between the BB-7017 Main drive gear, BB-7120 pilot bearing, and the BB-7061 Main shaft, and may lead to the transmission popping out of 4th gear under a load.
I could machine new spacers from scratch with either parallel faces or as a "D" shape with original thickness from the flat to the far side of the round. All of the wear is always on only one face, so why can't I just make a new spacer to original thickness with a "D" shaped cross section and place the round face as the wear surface? Has anyone ever done this? Is there a Ford engineering reason why the spacer must be round on both faces? Do you think Ford made it round like a "bull ring" just for cost reasons, or is the round cross-section key to lubrication flow and reduced contact area? Could both faces be parallel? An original Ford BB-7063 measures: OD=1.100, ID=.8125. wire diameter is .144