Knock Sensors - Early vs Late - Gold Pins
08-26-2011, 08:10 PM
#16
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From an Amp tech paper - "The Tin Commandments":
7. Mating Of Tin Coated Contacts To Gold Coated Contacts Is Not
Recommended
Tin-to-gold interfaces are more susceptible to fretting corrosion related
failures, and lubricants are not nearly as effective at stabilizing contact
resistance as they are with tin-to-tin interfaces. Tin tends to transfer onto
the gold surface which can ultimately lead to accumulation of tin oxide on
the harder gold substrate. It is more difficult to disrupt the tin oxide on the
harder gold substrate than it is to break through the tin oxide that forms
directly over tin.
The warning against mating tin with gold also applies to mating tin with
palladium and its alloys because the fretting behavior of tin-to-palladium and
its alloys is similar to that of tin-to-gold. This warning does not apply to the
case of the tin-to-silver interface because its fretting behavior is similar to
that of tin-to-tin.
http://www.te.com/documentation/whit...f/sncomrep.pdf
7. Mating Of Tin Coated Contacts To Gold Coated Contacts Is Not
Recommended
Tin-to-gold interfaces are more susceptible to fretting corrosion related
failures, and lubricants are not nearly as effective at stabilizing contact
resistance as they are with tin-to-tin interfaces. Tin tends to transfer onto
the gold surface which can ultimately lead to accumulation of tin oxide on
the harder gold substrate. It is more difficult to disrupt the tin oxide on the
harder gold substrate than it is to break through the tin oxide that forms
directly over tin.
The warning against mating tin with gold also applies to mating tin with
palladium and its alloys because the fretting behavior of tin-to-palladium and
its alloys is similar to that of tin-to-gold. This warning does not apply to the
case of the tin-to-silver interface because its fretting behavior is similar to
that of tin-to-tin.
http://www.te.com/documentation/whit...f/sncomrep.pdf
08-27-2011, 01:33 PM
#17
Chronic Tool Dropper
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Wally--
Is the fretting concern only on connectors that are repeatedly disassembled/assembled? There is no dielectric issue with the gold on tin with a dry connection.
Those thinking that dielectric grease will help... A very light smear on the sealing o-ring might help keep water out. Don't get any on the contacts themselves. Dielectric grease is an insulator. Dielectric grease is an insulator. Dielectric grease is an insulator. Dielectric grease is an insulator. Dielectric grease is an insulator. Repeat after me: Dielectric grease is an insulator.
Is the fretting concern only on connectors that are repeatedly disassembled/assembled? There is no dielectric issue with the gold on tin with a dry connection.
Those thinking that dielectric grease will help... A very light smear on the sealing o-ring might help keep water out. Don't get any on the contacts themselves. Dielectric grease is an insulator. Dielectric grease is an insulator. Dielectric grease is an insulator. Dielectric grease is an insulator. Dielectric grease is an insulator. Repeat after me: Dielectric grease is an insulator.
08-27-2011, 02:17 PM
#18
Under the Lift
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In alignment with what dr. bob says, I just use dielectric grease on the boot edges or plug o-rings, if present, to seal out moisture. Still, some advocate smearing it on the connection pins, as the grease is squeezed/scraped out of the contact area and acts as a water seal around the pin and receptacle if there is no other seal.
08-27-2011, 05:01 PM
#21
Chronic Tool Dropper
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Shark-Tuner 2. It's the tuning tool for LH and EZK brains used on the S4+ cars.