Pitman Arm Nut and Lock Washer - correct factory finish?

[gwp4]

Hi Camaro owners:

Looking to restore my 1968 Camaro back to its original condition.  Does anyone have information as to the correct finish on the Pitman arm nut (GM part 5667628) and the lock washer (GM part 5697702) for a manual steering gearbox?  Should the parts be phosphated or natural metal to be factory correct?  Many thanks. 

gwp4   

[Camarocards]

I remember that Chick went back and forth on what the correct finish for the nut should be during his restoration.  Here is a link to his build thread. I know the info is buried in this thread but I don’t recall what he wound up doing. I think at the end of the day the nut was phosphated.

https://www.camaros.net/forums/133-build-projects/182584-time-another-68-z-28-restored.html

Bob

[Edgemontvillage]

The nut and lock washer were both manganese phosphated. If you are seeking originality the threaded and splined section of the pitman /sector shaft was copper plated and should show some plating on the bottom when the nut and washer are attached.


Sector / Pitman Shaft copper plating
 

[68camaroz28]

I remember that Chick went back and forth on what the correct finish for the nut should be during his restoration.  Here is a link to his build thread. I know the info is buried in this thread but I don’t recall what he wound up doing. I think at the end of the day the nut was phosphated.

https://www.camaros.net/forums/133-build-projects/182584-time-another-68-z-28-restored.html

Bob

Good memory Bob and yes ours is phosphate as Lloyd describes.
By the way I’m working on a table of contents of my build thread and what a job. LOL

[169INDY]

Zinc (Nut) can be found out there also. (For My restorations)

Un restored photos 68/69 to follow ; Would it matter "IF" you are talking about PS -vs- Manual Box.

Jim

[Edgemontvillage]

Zinc (Nut) can be found out there also. (For My restorations)

Un restored photos 68/69 to follow ; Would it matter "IF" you are talking about PS -vs- Manual Box.

Jim

Jim, I have only seen manganese phosphated hardware on the pitman shaft for both power steering and manual boxes. This was  also the case during Vintage Certification at MCACN. Granted when original fasteners are 50+ years old and have been exposed to weather and road debris its more difficult to determine.   

   
    

[169INDY]

They must have used Both  as that would seem reasonable various suppliers etc.

1) Look at Dave Beem's 68 Z28 survivor  pages there are a couple good shots of he steering nut and In my estimation they appear to be plating that has seen limited decay. 

2) This is a photo of my 68 12E LOS car (86k mile) and the nut is clearly still plated as installed by GM. I figure the leaky seal on a PS car kept this nuts finish fresh 

I would imagine the location of this nut, lend itself to very harsh conditions given the driving location and storage of these cars and the appearance change with time and use.

just food for thought on the subject.  Yours looks great.

just offering info,

[68camaroz28]

Good info as I originally had ours restored phosphate washer and zinc nut but found out prior to Legends judging they want to see phosphate nut so I made the change so both were phosphate.