Topic: A/C idler bracket disassembly

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Now we can call you Scooter

[Bob Gaines]

To add to the discussion,the 67 mid 68 and the 68/69 pulleys are all black ,the brackets are bare steel/cast . The center caps on the 67 mid 68 are zinc silver and the 68/69 are P/O.

[67gtasanjose]

Assembly Tip:
Leave the bearing cap OFF of the assembly till after the correct pulley depth has been confirmed. In particular, this applies to at least the late-67 through 68 289/302 idler pulley (the one that mounts below compressor).

On this particular pulley, the one I did had unknowingly been pressed about an 1/8th-inch too shallow onto the bracket and this was not detected till after the assembly was bolted onto the engine, noticed with eyesight, having a slight deflection of the drive belt. A straight edge between the crank pulley and AC clutch pulley confirmed the deflection. I had already installed the center cap. At this point, o PREVENT pressing against the bearing for correcting the problem, I instead had to sacrifice a NOS pulley to rob the center cap from it. I then needed to drill a hole in my original center cap to remove it again (threading a screw into the hole)...this damage could have been avoided had I simply WAITED on tapping the center cap into place.

[Bob Gaines]

Assembly Tip:
Leave the bearing cap OFF of the assembly till after the correct pulley depth has been confirmed. In particular, this applies to at least the late-67 through 68 289/302 idler pulley (the one that mounts below compressor).

On this particular pulley, the one I did had unknowingly been pressed about an 1/8th-inch too shallow onto the bracket and this was not detected till after the assembly was bolted onto the engine, noticed with eyesight, having a slight deflection of the drive belt. A straight edge between the crank pulley and AC clutch pulley confirmed the deflection. I had already installed the center cap. At this point, o PREVENT pressing against the bearing for correcting the problem, I instead had to sacrifice a NOS pulley to rob the center cap from it. I then needed to drill a hole in my original center cap to remove it again (threading a screw into the hole)...this damage could have been avoided had I simply WAITED on tapping the center cap into place.

FYI there is no late 67 through 68 289/302 idler pulley. There is a fixed idler style (one that mounts below compressor)for all of 67 to mid 68 (cast bracket) and a different version for 68/69 (steel bracket). Also each different style of fixed idler has a specific BB and SB version.

[krelboyne]

Caps are the last thing to go on.
The 1967 caps are easy fits.
I hand fit all of the late 1968 and up caps. Straighten, true up roundness, and file notches to the indexed crimps. Once I am satisfied with the fit, they are JB welded to the pulley as the last step.

[67gtasanjose]

FYI there is no late 67 through 68 289/302 idler pulley. There is a fixed idler style (one that mounts below compressor)for all of 67 to mid 68 (cast bracket) and a different version for 68/69 (steel bracket). Also each different style of fixed idler has a specific BB and SB version.

Very early 67's DID NOT use the fixed bracket idler. I have done my research. As to when in 68 production they changed over, that I do not know.

[Bob Gaines]

Very early 67's DID NOT use the fixed bracket idler. I have done my research. As to when in 68 production they changed over, that I do not know.

If you mean the cast style fixed idler was used in 67 production then I agree. It read like you were referring to the steel bracket being the only one used in 67 all of 68. The cast style fixed idler was used starting in approximate March 1967 on both SB and BB Mustangs. That cast style matches the adjustable idler in material makeup. The change over to the steel style brackets and different pulleys happened in approximately March 1968.   

[69supercj]

To add to the discussion,the 67 mid 68 and the 68/69 pulleys are all black ,the brackets are bare steel/cast . The center caps on the 67 mid 68 are zinc silver and the 68/69 are P/O.

Hey Bob, just curious is the black sprayed or are they dipped? Also, forgive my ignorance but I'm assuming by P/O you mean phosphate and oil? Thanks for the info!!

[Bob Gaines]

Hey Bob, just curious is the black sprayed or are they dipped? Also, forgive my ignorance but I'm assuming by P/O you mean phosphate and oil? Thanks for the info!!

I have not seen drips or runs in the paint on original pulleys. They are a little shinier then semigloss which looks similar to the sheen on dipped parts.  I spray them and duplicate the look. P/O is short for phosphate and oil.

[J_Speegle]

Hey Bob, just curious is the black sprayed or are they dipped? Also, forgive my ignorance but I'm assuming by P/O you mean phosphate and oil? Thanks for the info!!

+1 on likely sprayed but on the glossier side

Example from a 69 boxed 69 application. Could have used a good wiping down before the picture but you can see a slight reflection in some of the better parts of the surface

[jwc66k]

+1 on likely sprayed but on the glossier side

Example from a 69 boxed 69 application. Could have used a good wiping down before the picture but you can see a slight reflection in some of the better parts of the surface

Because this idler has a moving part, it would not be dipped.
Jim

[Bob Gaines]

The pulley was painted(however) first. Then the components where pressed together into a assembly.  For example I have a 65 alt fan that was dipped by the drip evidence. I have not found any dipped evidence on the idler pulley's so don't know on that. The 65/66 upper control arm was one part that comes to mind that had a moving part and was also dipped. Apparently the the inner shaft and how it rotates when installed in the upper control arm was not effected by the dipping in paint.

[rockhouse66]

I don't know how they got such complete paint coverage on pulleys unless they were dipped.  A/C idler pulleys included.  When I restore one they always appear to have been painted all the way into the sheave which is pretty hard to do unless dipped.

[Bob Gaines]

I don't know how they got such complete paint coverage on pulleys unless they were dipped.  A/C idler pulleys included.  When I restore one they always appear to have been painted all the way into the sheave which is pretty hard to do unless dipped.

Like I said I am not sure how the idler pulleys were painted.  I do know that a authentic finish can be achieved by spray. The end finish is the goal. how you get there is the challenge. They could have been dipped . The production problem I see in a dipped scenario on a idler pulley is getting paint on the inside surfaces where the bearing is pressed in. The paint would create clearance problems I would think when trying to press a bearing in with paint in the way. Maybe difficult to get good coverage on a pulley in one spray paint pass .This is just me not doing anything special other then multiple coats for coverage but it never seemed difficult when I had to spray paint one to get complete paint coverage. I have had many original water pump pulleys that had foggy paint line on the back side which would indicate spray others with faint drips so at least not all were dipped. 

[J_Speegle]

Did start a new thread focused on the original finishes of the engine pulleys since some of the discussion is moving away from just the idler pulley and just because it might be helpful to others.

http://www.concoursmustang.com/forum/index.php?topic=21652.new#new