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Rusted out Rear subframe 2007 g35x HR steel to alluminum?
I just got a 2007 g35x and after taking off the bottom rear splash guard plastic I realized the rear subframe is rusted out and collapsed in the rear two mounting points. All replacements I have found to be are an aluminum subframe. I have found a one from a g35 coupe aluminum that I could replace. My concern is since mine is steel since it's rusted, can this swap work. Mine is the HR awd. I took some measurements and the four main mounting wholes seem to match dimensions.
Another question, there is a bar connecting both rear subframe mounts and has a bracket in the middle connecting the bottom splash guard. I need a replacement and I'm not sure what it is called.
If anyone couple help me out I would greatly appreciate it thank you.
So much for safety's now a days.
Last edited by Lastonepro; Apr 7, 2023 at 09:59 PM.
Reason: Subframe to rear subframe
The 2003-2006 sedan and 2003-2007 coupe is the V35 chassis which uses the aluminum rear subframe.
The 2007-2008 sedan is the V36 chassis which uses the newer steel rear subframe. All the V36 chassis from 2007+ are technically interchangeable but the 2009+ uses 4 different bolts for the sway bar bracket.
The V35 and V36 are not interchangeable, the recommended solution for the rusted 2007-2008 subframes is to replace it with the 2009+ V36 chassis frame which has SUBSTANTIALLY better factory coating
Nissan part numbers that will work are 55400-JK10B which was 2009-2011 G37, 55400-JK00A which was 2011-2015 Q50/Q60, or the most current revision which covers all those V36 platform cars Nissan part number 55400-JK00B. All those older revisions are discontinued but you can use those parts numbers to help source a replacement used frame either online or locally at a salvage yard. New they run about $1000, used can be as low as $300.
Even if you did end up sourcing a non-rusted older steel subframe you can always coat it with rustoleum undercarriage spray to prevent it from rusting again in the future.
These newer subframes from the G37 and Q50/60 also requires different bolts for the sway bar mounting brackets, you need 4x of Nissan part number 54459-0P03E if you use the newer frames.
Just don't buy the aluminum frame and you're good, also there's probably other parts that need replacing but you should wait until you have it apart and wire wheel everything thoroughly to see what's usable and what's not. Your rear stay main and the side stay brackets are probably not usable but it's hard to tell when they're all covered in rust. Once cleaned up they might be just fine.
The 2003-2006 sedan and 2003-2007 coupe is the V35 chassis which uses the aluminum rear subframe.
The 2007-2008 sedan is the V36 chassis which uses the newer steel rear subframe. All the V36 chassis from 2007+ are technically interchangeable but the 2009+ uses 4 different bolts for the sway bar bracket.
The V35 and V36 are not interchangeable, the recommended solution for the rusted 2007-2008 subframes is to replace it with the 2009+ V36 chassis frame which has SUBSTANTIALLY better factory coating
Nissan part numbers that will work are 55400-JK10B which was 2009-2011 G37, 55400-JK00A which was 2011-2015 Q50/Q60, or the most current revision which covers all those V36 platform cars Nissan part number 55400-JK00B. All those older revisions are discontinued but you can use those parts numbers to help source a replacement used frame either online or locally at a salvage yard. New they run about $1000, used can be as low as $300.
Even if you did end up sourcing a non-rusted older steel subframe you can always coat it with rustoleum undercarriage spray to prevent it from rusting again in the future.
These newer subframes from the G37 and Q50/60 also requires different bolts for the sway bar mounting brackets, you need 4x of Nissan part number 54459-0P03E if you use the newer frames.
Just don't buy the aluminum frame and you're good, also there's probably other parts that need replacing but you should wait until you have it apart and wire wheel everything thoroughly to see what's usable and what's not. Your rear stay main and the side stay brackets are probably not usable but it's hard to tell when they're all covered in rust. Once cleaned up they might be just fine.
