Author Topic: Why did Ford use Blue Nuts on their Struts?  (Read 4121 times)

Offline 79mustangcobra

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Why did Ford use Blue Nuts on their Struts?
« on: February 18, 2015, 01:20:09 PM »
I was looking at this 300 mile 79 Pace Car I use for a reference on my restoration and wondered why Ford used Blue nuts on the struts?

Was it for the warranty?  For a quick visual?

Please see picture below - thanks!

1979 Mustang Cobra 5.0
2P Red and 1C Black

Stock never goes out of style
MCA #70281 -  79-93 MCA Concours Judge
Proverbs 3:5-6

Offline rodster

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #1 on: February 18, 2015, 07:47:23 PM »
Don't know, but Ford also used blue nuts some places on SVO's too.  Don't think struts was one of them tho.  Interesting picture.
1965 Dearborn Mustang Coupe
Raven Black - Palomino Pony
1967 Dearborn Mustang Conv.
Wimbeldon White - Red
1984 SVO - 2A

Offline svo2scj

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #2 on: February 19, 2015, 09:43:51 PM »
Call out for attention to TORQUE spec.

Guns were matched at station
1969 R Code , Sportsroof (non Mach) W Axle
AB , Standard Interior  San Jose built 4/22/1969

Offline rodster

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #3 on: February 20, 2015, 12:27:37 AM »
I can understand that for the strut nuts, but the small miscellaneous SVO nuts?
1965 Dearborn Mustang Coupe
Raven Black - Palomino Pony
1967 Dearborn Mustang Conv.
Wimbeldon White - Red
1984 SVO - 2A

Offline Smokey 15

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #4 on: February 20, 2015, 12:45:45 AM »
 The cars with the blue ones were built by married guys, maybe?     

 Seriously, could just be what was available from the supplier at that time.

Offline 79mustangcobra

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #5 on: February 27, 2015, 06:13:45 PM »
Call out for attention to TORQUE spec.

Guns were matched at station

That's cool, thanks for the info.
1979 Mustang Cobra 5.0
2P Red and 1C Black

Stock never goes out of style
MCA #70281 -  79-93 MCA Concours Judge
Proverbs 3:5-6

Offline 79mustangcobra

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #6 on: April 22, 2015, 04:35:48 PM »
Well after reading this months Hemmings Muscle I 'May' have an answer

They had an article on this 1979 Oldsmobile Hurst/Olds





So is this the reason the nuts were blue on the 79 Mustang's Struts?
1979 Mustang Cobra 5.0
2P Red and 1C Black

Stock never goes out of style
MCA #70281 -  79-93 MCA Concours Judge
Proverbs 3:5-6

Offline Smokey 15

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #7 on: April 22, 2015, 07:13:14 PM »
 That is true. I have owned quite a few GM "G Bodies" and they had a mix of S.A.E. fasteners and metric.  The metrics were blue. I still have some of them.  Not sure if that applies to Ford, but it makes perfect sense.

Offline 79mustangcobra

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #8 on: April 23, 2015, 10:15:53 AM »
That is true. I have owned quite a few GM "G Bodies" and they had a mix of S.A.E. fasteners and metric.  The metrics were blue. I still have some of them.  Not sure if that applies to Ford, but it makes perfect sense.

I may be barking up the wrong tree, not sure of my 'hypothesis" we shall see.  Thanks! :)
1979 Mustang Cobra 5.0
2P Red and 1C Black

Stock never goes out of style
MCA #70281 -  79-93 MCA Concours Judge
Proverbs 3:5-6

Offline svo2scj

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #9 on: April 23, 2015, 04:39:30 PM »
I maintain that it was just a TORQUE call out.      While the struts were important to be torqued to a specific torque , other "blue" bolts were different torques.

On the assembly process sheets these nuts are footmarked with ^ and torque amounts.    In the case of the alternator brace added to the 85.5 SVO they used a blue nut - front on steel alternator bracket is 18-22 FT LBs, while the back of the brace on the manifold stud to alum (blue) is 6-9 ft lbs.    CARE was to be used. That same care needed to be used on the rubber issolators of the VAM - in that case LOW torque 6-9 Ft Lbs.

Probably the best area for this (and missed by mechanics) is the Knock Sensor - called out to 6INCH LBS !   (over tighten an they don't even work)

Mark
P.S.  Not the first time dye was used as call out - look at the steering box bolts on early Mustangs (red) - again critical torque area.   (ever seen a collapsed frame rail from over tightening)
« Last Edit: April 23, 2015, 06:18:36 PM by svo2scj »
1969 R Code , Sportsroof (non Mach) W Axle
AB , Standard Interior  San Jose built 4/22/1969

Offline 79mustangcobra

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Re: Why did Ford use Blue Nuts on their Struts?
« Reply #10 on: April 24, 2015, 03:43:27 PM »
I maintain that it was just a TORQUE call out.      While the struts were important to be torqued to a specific torque , other "blue" bolts were different torques.

On the assembly process sheets these nuts are footmarked with ^ and torque amounts.    In the case of the alternator brace added to the 85.5 SVO they used a blue nut - front on steel alternator bracket is 18-22 FT LBs, while the back of the brace on the manifold stud to alum (blue) is 6-9 ft lbs.    CARE was to be used. That same care needed to be used on the rubber issolators of the VAM - in that case LOW torque 6-9 Ft Lbs.

Probably the best area for this (and missed by mechanics) is the Knock Sensor - called out to 6INCH LBS !   (over tighten an they don't even work)

Mark
P.S.  Not the first time dye was used as call out - look at the steering box bolts on early Mustangs (red) - again critical torque area.   (ever seen a collapsed frame rail from over tightening)

That is a good point Mark!  I am going to have to dig deeper.  Thanks for your input!
1979 Mustang Cobra 5.0
2P Red and 1C Black

Stock never goes out of style
MCA #70281 -  79-93 MCA Concours Judge
Proverbs 3:5-6