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Discussion Starter #1
I have an 07 QP Executive GT Automatica.
The other day I was having the resonator changed and while on the lift, had a look at the underside as a a general inspection. To my surprise, I found the rear transmission bracket cracked in half. I immediately ordered a new one had it replaced this morning.

After inspecting the original, I am somewhat baffled, if not concerned. This vehicle has 20K miles and is very well cared for. It's not abused or neglected on any level. I've had this car serviced and a complete inspection by Maserati Service last year with zero defects. Having said all of that, the broken part shows no signs of impact damage that may have cause the break and I am absolutely sure that I hit nothing. There is no damage to anything else under the car.

Does any know why this part failed? Has anybody else experienced the same issue. I'm just curious, as I am considering changing all the mounting brackets. Before doing so, I'd like to know if this a common or known issue.

Any information is most appreciated.

Thank you,
Jeff
 
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Never see none crack...It may have just had a casting flaw in it from manufacturing...Broken brackets are not common at all....Jason
 

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Discussion Starter #3
Never see none crack...It may have just had a casting flaw in it from manufacturing...Broken brackets are not common at all....Jason
Hi Jason,
Thank you for the reply. Hopefully, it's a one of a kind issue. This thing broken completely in half. I replaced it and the bushing, but the old bushing is still like new.

Anyway, I'll just keep an eye on the mounts and see if there are any other issues.

Happy Miles,
Jeff
 

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Sorry for the delay in posting these... it was my anniversary which required me choose between spending time with my wife ... or my car. Decided that if I want to keep the car ... well... you get the picture :). Anyway, here are a few photos... pre-removal and post. There are no signs impact to the bracket and there is damage or signs of impact on any other part on the undercarriage. This car has less than 25k miles on it and is not abused at all. I appreciate all perspectives, as it concerns me a bit if these brackets are failing.
133501
 

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the black marks on pictures 2 and 3, is it dirt or the metal discolored? failure of the casting exhibits no noticeable ductility on picture 2 but picture 3 left vertical plane looks like a clean break (could just be the angle of the picture).

Asking a couple of buds. Been a while since I had done failure analysis.
 

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Discussion Starter #9
The discoloration is, in fact, dirt. The break is clean, as seen in Pic 1. There was no visible damage. I would think if this was an impact break, it would have to been at least hard enough to scuff the metal. As you can see, there are no scuffs, dents, or other
 

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The bolt in the first picture that looks rusty and goes through the hole in the second picture, is it rusty and is it OEM? Plus what goes in the hole on the second picture. They noticed the bolt hole to be is stretched oblong and has thread indentations on the side.
Told them no impact but did not state year or mileage. I will update them.
From the info so far, they think the bolt was not torqued correctly. 2 guys replies.

Guy 1: I'm looking at the rusty nut and bolt in the first photo. It looks to me like it is not OEM. The bolt hole in the casting is also stretched. Since you say there's no discernible impact damage, it could be the bolt was under-torqued and/or under-sized and contributed to the failure. The failure mode looks like a flexural issue. We need more information. What goes in the hole - an isolator of some sort?

Guy 2: Or could it have been over torqued, caused a small crack that under went cyclical loading? The chewed up section almost looks like it was rocking side to side?

Guy 2: Did the same type/dimension bolt come out of both locations as Dean pointed out? It looks like possibly the wrong hardware was used and allowed it to fatigue over time. Could be as simple as improper torque, but taking a look at the receiving threads would tell you if the bolt moved around a bunch. Seems like a pretty specific shoulder bolt needed to be in that pocation, but no clue what was sctually used. The dirt on the cracked edge says this wasn't a quick failure.

Guy 2: One other thing, are there any other failures where this part attaches? Did the parts this bolts to move enough due to other problems that broke the casting? Hopefully this isn't just the most noticeable issue and you have a major problem yet to be discovered.

Guy 1: I think the rusty bolt is the root of the failure. Look at how the hole is stretched oblong and has thread indentations on the side. The face of the boss shows fretting from movement. Engineers for OEM spend a lot of time on fastener design and torque specs to make sure they don't fight unnecessary law suits.

Guy 2: Agreed. Thats the most likely cause of failure at this point.
 

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Discussion Starter #11
Thank you for the responses.
I've owned this car for the past 12 years. It has 19,700 miles on it. Service ONLY by Maserati and any parts the need replaced are all authentic Maserati (primarily ordered from Scuderia)

This part has never, to my knowledge been changed. I do know the mechanic has a difficult time removing the bolt that was in the "oblong" hole.
The two smaller holes are used for a plate of sorts (shown in the picture prior to removal)

With respect to the potential of other unseen ancillary consequential problems, I did a very close inspection of the the area and found nothing to indicate problems. In fact, though I did replace it, the bushing was in perfect condition with no signs of wear or rubbing . . no damage at all.

I thank you all for the input. This may simply have been "just one of those things" . . . I'll keep an eye... and ear on it. and continue to absolutely enjoying driving this car!

Thank you again.
Jeff
 

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Sorry i meant i do not state the year or mileage when i asked my friends about an opinion the first-time just that no impact to part. I informed them yesterday and pass along the more info you just posted.
 

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There was a change of the bolts , in the parts catalog there is an old and new version , but no explanations what is changed.
 

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Discussion Starter #15
Hmm . . very interesting . . . Thank you for this. I'll make some inquiry at the dealership service and try to get the details.

Thank you again . . . perhaps it was the rust :)
 
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