Author Topic: Idler Arm Washer Finish ~Natural? Phosphate & Oil? or Zinc?  (Read 588 times)

Offline 67gtasanjose

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Idler Arm Washer Finish ~Natural? Phosphate & Oil? or Zinc?
« on: February 08, 2017, 08:41:09 AM »
Attached is a picture for reference, the two larger washers seen.  I want to say Phosphate and Oil, but wish to confirm.

Working on a 67 with power steering but likely the same finish for all classic Mustangs so I posted it here.


« Last Edit: February 17, 2017, 07:03:54 PM by J_Speegle »
Richard Urch

1967 (11/2/66, S.J.) Luxury Coupe, 289-4V w/Thermactor Emissions, C-4, Well Optioned
2005 (04/05) GT Premium Convertible, Windveil Blue, Parchment Top w/Med. Parchment interior,  Roush Body Appointments

Online 67350#1242

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Re: Idler Arm WASHER FINISH ~Phosphate & Oil or Zinc?
« Reply #1 on: February 08, 2017, 10:39:19 AM »
On NOS idler arms that I've seen, the washer on bracket end appears to be natural finish.  I believe that is also the case for the center link washer.
« Last Edit: February 08, 2017, 10:41:37 AM by 67350#1242 »

Offline 67gtasanjose

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Re: Idler Arm WASHER FINISH ~Phosphate & Oil or Zinc?
« Reply #2 on: February 09, 2017, 07:07:39 AM »
I've checked the assembly manual and have confirmed that washer 379297-S is intended for use at the center link end. This washer matches size anyways of the one I removed from the idler arm bushing to shaft location. I suppose I could assume assembly line versions also had the NATURAL FINISH on both washers.

AMK has no listing on this item per say. Perhaps I could measure the washer and see if a substitute in the correct finish is available with a different AMK listing or cross reference. I have located a hardware store washer (zinc plated) that matches the two washers removed in size and thicknes and I suppose I could simply remove the zinc and throw those in a tumbler.

Looking for what others are doing or have done for these washers.
« Last Edit: February 09, 2017, 07:15:22 AM by 67gtasanjose »
Richard Urch

1967 (11/2/66, S.J.) Luxury Coupe, 289-4V w/Thermactor Emissions, C-4, Well Optioned
2005 (04/05) GT Premium Convertible, Windveil Blue, Parchment Top w/Med. Parchment interior,  Roush Body Appointments

Offline Bob Gaines

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Re: Idler Arm WASHER FINISH ~Phosphate & Oil or Zinc?
« Reply #3 on: February 09, 2017, 05:34:13 PM »
I've checked the assembly manual and have confirmed that washer 379297-S is intended for use at the center link end. This washer matches size anyways of the one I removed from the idler arm bushing to shaft location. I suppose I could assume assembly line versions also had the NATURAL FINISH on both washers.

AMK has no listing on this item per say. Perhaps I could measure the washer and see if a substitute in the correct finish is available with a different AMK listing or cross reference. I have located a hardware store washer (zinc plated) that matches the two washers removed in size and thicknes and I suppose I could simply remove the zinc and throw those in a tumbler.

Looking for what others are doing or have done for these washers.
I have a couple of NOS ones and the washer appears to be a very light P/O or gun blued. I think ether process will give the desired look . I don't think the assemblyline ones were bare steel with no type of plating otherwise i would find them in a much more deplorable pitted state then I typically do.
Bob Gaines,Shelby enthusiast, Shelby collector , Shelby concours judge SAAC,MCA,Mid America Shelby

Offline jwc66k

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Re: Idler Arm WASHER FINISH ~Natural? Phosphate & Oil? or Zinc?
« Reply #4 on: February 09, 2017, 07:17:42 PM »
The process that made large washers used a special lubricating oil (aka cutting oil?) in the stamping so residual oil would be present. That may have been the only rust preventative on them. For restoration, I bead blast, lightly phosphate (1 1/2 to 2 minutes at 190F +) and then oil. It's is a better alternative than nothing, or wire brushing. I've seen a "bluish tint" on cut edges from the tool being over used. The oil was also supposed to remove excessive heat. At least in theory.
Jim
I promise to be politically correct in all my posts to keep the BBBB from vociferating.