RACP Failure After Plates

[Dash1]

thats a lot of cracks and after a 190k, the metal is pretty much fatigued. you may squeeze a little more life out of that RACP but im sure the cracks will come back. with that kinda, damage, its best to go with a whole new panel IMO

I wouldn't say a whole new panel. But definitely Vincebar/CMP type reinforcement is needed as it relieves the carrier panel from most of the stress from the subframe. I'd say its important to weld any existing cracks before installing one of the said components as well.

[Dash1]

Plates are not a fix.

Did you read my post?

[Dash1]

Climate where car was for those 90k?

Southern California for its entire life. Dry heat, no ocean spray.

[Obioban]

Plates are not a fix.

[Maxima SE]

~90k miles between plates and now. Currently sitting at 190k. And no, the subframe bushings were replaced the last time with stock bushings.

thats a lot of cracks and after a 190k, the metal is pretty much fatigued. you may squeeze a little more life out of that RACP but im sure the cracks will come back. with that kinda, damage, its best to go with a whole new panel IMO

[Tbonem3]

Climate where car was for those 90k?

[heinzboehmer]

~90k miles between plates and now. Currently sitting at 190k. And no, the subframe bushings were replaced the last time with stock bushings.

Oh wow I assumed the interval between plate install and now was much shorter. Honestly looks better that I though for having had plates and no topside reinforcement for 90k miles.

[Dash1]

How many miles did the car have when the plates were welded on, and how many does it have now? Did it have the same stock subframe bushings this whole time?

~90k miles between plates and now. Currently sitting at 190k. And no, the subframe bushings were replaced the last time with stock bushings.

[r4dr]

How many miles did the car have when the plates were welded on, and how many does it have now? Did it have the same stock subframe bushings this whole time?

[Dash1]

Yes yes, we all know plates isn't the end all be all for RACP failure yaddah yaddah yaddah. I am by no means saying I was surprised, I just wanted to share an experience and with visual evidence - especially since M3F is no longer here and there were a lot of resources there regarding this matter.

Anyway, my car has TMS reinforcement plates installed and previously had stock subframe/differential bushings. I've always kept an eye on the rear despite the fact for exactly this reason. My car is an '04 so it has the updated spot welds as well. And she is also tracked and driven (I think) like a proper M car. Here are the cracks which I initially found.












































Once I took it to the shop and they took off the sound deadening and dropped the subframe they found additional cracks. The RACP was tearing itself apart!



As you can see, once the plates are installed the mounting points are no longer the weak spot and the stress continues to flex the RACP. I knew it would have additional cracks but I didn't think it was going to be this bad. The cracks were stitched up and I went with the Turner Delrin/Aluminum subframe bushings and AKG poly diff bushings. All in all I'm very impressed how well the car feels now. Solid, direct, and with a teeny weeny little diff whine - which I kinda like haha. The whine has actually attenuated since I first drove it to where I barely hear it even with windows up and stereo off.



Now that she's back on the road I'm thinking of preventative measures to prevent this from happening again. I have an xbrace which I bought and haven't had the time to install. But from my understanding, it only addresses the rear two mounting points. So if I install it, I have to somehow address the front two points. I'm sure the RACP will hold on until I figure out a solution, especially with the solid subframe bushings. I think that made the biggest difference in terms of reducing flex in the rear.