7A trans noise at idle? Flex plate?

AstatenateZ

I’ve attached a video link below. The trans shifts up/down fine, drives fine, noise is only there at low RPM’s when in P, R, D , in neutral it’s less noticeable. But still slightly there. No fluid leaks. Noise is 100% coming from trans. And noise goes away once I’m driving. I’ve researched and only found flex plate issues. So I’m guessing it’s my flex plate is cracked or about to be cracked / loose.

I’ve been looking for videos or threads on how to remove 7A trans and only found 6M removals. I’m assuming process is the same minus a few slight changes. Also if I’m replacing flex plate. Do I need any other parts? Gaskets? Bolts not able to be reused, etc?



Video link of noise here >>
https://youtu.be/tu0g07mAXo0

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AstatenateZ

Bump for feedback

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jchammond

Sounds like it & possibly exhaust leak too (could be video)
There should be a cover to take off for gaining access to bolts connecting flex plate to torque converter.
I haven’t removed mine yet; but I can download some information from work on removal process. After bolts are removed from flex plate to converter ~ push converter towards transmission (the way I’ve done them all to avoid mess). Driveshaft removal is basic; remove (4) bolts w/nuts from pinion shaft flange & it slides out of trans.
You’d probably want to drain before removal; (19mm) hex plug near rear of pan & fill plug is the (5mm) allen near the front.
Also; Fast Intentions sells a Billet Aluminum flex plate for these - contact Kevin or Tony & they may give you some tips on removal.
I’ll see what I can dig up from work; but shouldn’t be too tough...

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MazWorx built long block | FI-TT-100 Stage 2.75 | IPT built 7A/T

http://www.the370z.com/members-370z-...s-musings.html

KN21283

I had the same noise and thought it was the flex plate too but end up being the *valvebody. The line pressure wasn’t holding.

jchammond

That’s not good
As I haven’t heard or have learned the failure noises from the valve bodies on these transmissions...did you get a reman or just have the valve body replaced?
New ones are pricey & the oem remans are a few thousand less.
My knowledge of the oem reman is, they use all new internals on a used case...but brand new is brand new everything.
Internet pricing on new is 75-8500, with list price over 9600 & reman is a few K less...wish you the best of luck.
Got swamped at work yesterday with roadcalls & didn’t get opportunity to download r&r procedures.

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MazWorx built long block | FI-TT-100 Stage 2.75 | IPT built 7A/T

http://www.the370z.com/members-370z-...s-musings.html

KN21283

I had it replaced with a new oem which took a bit work to source. It cost $1500-1700 and was upgraded along with the 7AT.

I had AAM handle my build(2014), they claimed to have sent the valvebody to level10 to upgrade. My car never ran as expected from AAM, so I had some else check it out.

In the end AAM gave me false info on whp, a shotty build and cost me a transmission.

AstatenateZ

Finally got around to pulling trans today, found cracked flex plate just as I expected. Will be replacing soon!

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jchammond

You called it; glad it wasn’t the valve-body.

Attached Images

7BB88327-A61E-45EA-8C49-7A03D011CE1F.jpg (77.6 KB, 9 views)

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MazWorx built long block | FI-TT-100 Stage 2.75 | IPT built 7A/T

http://www.the370z.com/members-370z-...s-musings.html

old guy

What would cause the flex plate to crack like that ?

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I better walk before they make me run....

AstatenateZ

Me too $50 used for an OE flex plate or $250 for brand new OE flex plate vs $900-1000+ for a valve body is a lot better! I’ll prob just replace with OE because I don’t plan on keeping the car a whole lot longer.


I hear they’re just a weak point, power output from boosted applications, high speeds and/or high RPM’s on a full bolt on + tuned Z could also cause it.

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old guy

Good to know, Thanks

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I better walk before they make me run....

AstatenateZ

Heard it can happen to 100% stock Z’s tho. It’s just a weak point. Added power bolt on or boosted. Just worsens the issue.

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