Creaking /Popping Noise

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Fless

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You must have had that noise before the idler arm replacement, to find what you described. the GT4 is the RPO code for the 3.73 gear but G80 would be the limited slip diff. The G65 is not one I am familiar. The G66 and G67 have to do with auto and manual leveling.

G65 is the RPO code for the rear manual self-leveling Nivomat shocks, if they're still on the truck. Part of the Premium Smooth Ride option.
 

OR VietVet

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G65 is the RPO code for the rear manual self-leveling Nivomat shocks, if they're still on the truck. Part of the Premium Smooth Ride option.
I looked at 2 different GM RPO codes lists and they both went G60 and the G66 and then G67 and did not show the G65.
 

mrutah12

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You must have had that noise before the idler arm replacement, to find what you described. the GT4 is the RPO code for the 3.73 gear but G80 would be the limited slip diff. The G65 is not one I am familiar. The G66 and G67 have to do with auto and manual leveling.
ya went back through codes. just gt4 -3.73 nothing says its a posi . so i guess i get to disassemble the rear diff over the holiday weekend i know its a 10 bolt and it says 8.6 on the ring gear. there are some other numbers im not familiar with.
 

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OR VietVet

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ya went back through codes. just gt4 -3.73 nothing says its a posi . so i guess i get to disassemble the rear diff over the holiday weekend i know its a 10 bolt and it says 8.6 on the ring gear. there are some other numbers im not familiar with.
So....are you planning on installing the gears yourself?
 

OR VietVet

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This thread has been hijacked and I am sorry for that. Hopefully a moderator can move part of it to another spot. @mrutah12, in the future, if you have a problem on your vehicle, you really should start your own thread. That helps you get more responses to your concern.
 

Fless

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ya went back through codes. just gt4 -3.73 nothing says its a posi . so i guess i get to disassemble the rear diff over the holiday weekend i know its a 10 bolt and it says 8.6 on the ring gear. there are some other numbers im not familiar with.

If you have G80, which you surely do:

1688218776648.png
 

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