ANOTHER Broken motor mount........ Its my turn

[TorqSpeed5252]

The more I research this bolt grade thing the more I find that I don't like. Attached are scans from our metric fastener standard here at work which encompasses ASME, ASTM, SAE, and IFI. Look at Tables 3 & 7. If I'm right (and I'm not saying I am) that is a grade 8 metric bolt. Which is equivalent to an American Grade 5!! I'm thinkin about saying to hell with not being sure and buying a grade 12.9 structural bolt and throwing it in there until Mazda issues a new bolt or a redesigned mount. Although I'm not advocating or encouraging anyone to do this, this is only my opinion (cover my ass disclaimer).

There is also an attchment concerning red loctite #266 (which is the high temp, high strength loctite) and factors that effect application strength.

 

[maestro]

Whoa. You're in a thread about the transmission engine mount bolt breaking. You'd definitetly know it if it was that, 'cause the driver's side of the engine would've broken a bunch of things on the way down. If you're talking about your aftermarket SU mount, you should have been able to see that from under the car.

Anyhow, let us know what the dealer says.

yea, the engine would not be able to go anywhere if it was the bolt through the rear mount below the firewall. The mount is sandwiched in there.
I have an 08/06 build date on mine and I have checked the bolt under the battery and it was fine.

I would love to see some pics of the mount/bolt after breaking. Also waiting to hear what happens at the dealer.

 

[speedi3]

Here the verdict as described on the work order (I'd scan it but not to bright):

Customer states loud knock noise over bumps - customer./owner suspects motor mounts - CP CK for loud knocking noise - After market motor mount, Bolt missing - Replace missing Bolt and Loc-tite in place - Test drive good.

When I talked with the service rep he said they had to "make me a new bolt" I will get under the car and see what the number is on the bolt and report back to the group. All is well for now. I drove (unknowingly for about 30-40 miles with out the bolt) I did however keep my old mount as this was $80 just for a FN bolt... BUT I am ever so thankful that it wasn't anything more.

 

[speedi3]

First off SpeedI3 can you drive your car? if so the bolt isn't broken yet. when the motor fals it destroys a bunch of stuff.

Second the bolt used is only stamped with an 8. now if its was a american bolt i would assume grade 8, but since its metric and metric bolts use something like 10.8 and 12.8 for strength, i have no idea what this bolt is rated at.

Last thing I'm leaving now to catch the tech reps at the dealer. my little birdy said they just got there.

This NEW bolt is stamped 8.8.

 

[ptperformance]

Well here's the problem with that. If you modify the OEM bolt from it's original state with any "improved" bolt and that bolt happens to break, I'm willing to bet Mazda may say, "hey you installed an aftermarket bolt and the bill is on you." Sure there are a few options like a bolt & nut combination or even a bolt & nut with safety wire/cotter pin but...

After getting up close today, I personally believe the mount needs to be reengineered. The bolt should be horizontal from front to back, not vertical and absorbing the significant amount of pull that it has on it.

That is what we are working on but there is very little room to work with. The other problem, one bolt hole to work with, not much option wise to support the tranny. I am taking a look at a strap kit that is a "just in case" it breaks type of support/catch for that side of the motor if it breaks. Still working on it but the room that we have its a major issue.

 

[M3_Zoom]

Here the verdict as described on the work order (I'd scan it but not to bright):

Customer states loud knock noise over bumps - customer./owner suspects motor mounts - CP CK for loud knocking noise - After market motor mount, Bolt missing - Replace missing Bolt and Loc-tite in place - Test drive good.

When I talked with the service rep he said they had to "make me a new bolt" I will get under the car and see what the number is on the bolt and report back to the group. All is well for now. I drove (unknowingly for about 30-40 miles with out the bolt) I did however keep my old mount as this was $80 just for a FN bolt... BUT I am ever so thankful that it wasn't anything more.

So then your problem was the rear aftermarket mount? The mount that has major issues and the bolt breaks or backs out, is the side mount under the battery box, not the rear mount. Also the side mount is the one that breaks and causes your engine to drop. The rear mount can be removed without even supporting the engine/transmission. WOW! I hope if you experience this again you first look under your car and save yourself $80.

 

[speedi3]

So then your problem was the rear aftermarket mount? The mount that has major issues and the bolt breaks or backs out, is the side mount under the battery box, not the rear mount. Also the side mount is the one that breaks and causes your engine to drop. The rear mount can be removed without even supporting the engine/transmission. WOW! I hope if you experience this again you first look under your car and save yourself $80.

No just like everyone else the bolt for the aftermarket rear mount is what broke. Problem is you couldn't tell from just looking at it. I didn't have a lift.... It appeared there but it was gone.

I reinstalled the HBOV. Its huge and scraps the top of the air duct(when the mount is broke) for the tmic and is my early indicator that i have a Rear Motor mount problem!!! (hand)

 

[M3_Zoom]

No just like everyone else the bolt for the aftermarket rear mount is what broke. Problem is you couldn't tell from just looking at it. I didn't have a lift.... It appeared there but it was gone.

I reinstalled the HBOV. Its huge and scraps the top of the air duct(when the mount is broke) for the tmic and is my early indicator that i have a Rear Motor mount problem!!! (hand)

Hmmm, so your rear lower mount bolt was broke but you couldn't tell? So the bolt broke in half but remained in place? I'm sorry for asking so many questions, I'm just trying to figure out what your saying. I can jack my car up on the drivers side just a little bit, place a jack-stand underneath for safety, slide underneath and there it is.

I think for myself and maybe a few other we were under the impression your side mount was the one failing.

 

[maestro]

No just like everyone else the bolt for the aftermarket rear mount is what broke. Problem is you couldn't tell from just looking at it. I didn't have a lift.... It appeared there but it was gone.

I reinstalled the HBOV. Its huge and scraps the top of the air duct(when the mount is broke) for the tmic and is my early indicator that i have a Rear Motor mount problem!!! (hand)

Unless I misread the original post, this thread is mostly dealing with the mount under the battery that holds that end of the engine/trans up.
The rear mount has apparently had problems with the bolt breaking, however this will not cause the damage that dropping the trans/engine on one side will. The way the rear mount is bolted in, the mount itself would have to break to allow the engine to roll backwards far enough to break other mounts.

 

[M3_Zoom]

Unless I misread the original post, this thread is mostly dealing with the mount under the battery that holds that end of the engine/trans up.
The rear mount has apparently had problems with the bolt breaking, however this will not cause the damage that dropping the trans/engine on one side will. The way the rear mount is bolted in, the mount itself would have to break to allow the engine to roll backwards far enough to break other mounts.

+1. Justa4banger has had the side mount bolt under the battery box break and as maestro said, that was the original post. Hopefully we receive an update from him soon.

 

[speedi3]

+1. Justa4banger has had the side mount bolt under the battery box break and as maestro said, that was the original post. Hopefully we receive an update from him soon.

IC... I was referring to the rear mount. I don't have an aftermarket side mount.

 

[M3_Zoom]

IC... I was referring to the rear mount. I don't have an aftermarket side mount.

As for your rear mount, check the torque on them and the three on the mounting bracket. (66 - 86 ft/lbs) I went in the middle with 76ft/lbs and then mark them as I showed on the side mount earlier. Now until all this gets figured out I can quickly get underneath the car and look at the marks and know if the bolts moved or not.

On the side mount, there is no aftermarket mount yet. Not even a bolt, yet alone a TSB, but I'm sure there will be soon. Currently, the NHTSA has an open investigation going.

 

[justa4banger]

Ok Heres The Update!!!!!!!!!!!!!!!

UPDATE!!!!!!!!

Well because my buddy is the parts manager he woke me up this morning to tell me the tech reps are in and looking at my car.
First off these guys were true Japanese people, broken english and all it quite funny i thought. (nothing against asians .....Wait i'm asian lol ).

Anyways. heres the dealio.
I didn't get a chance to take a picture of the bolt but my bolt had a slight bend it and a breaking point where it looked like someone used a set of bolt cutters to first cut half way through the bolt, then the rest was snapped off.
First question they asked was if i speed shifted the car. I answer no. Never do as its not worth the 1/10th of sec and thrashed synchro's
they then progress to explain to me why this is happening.

In their words the mounting system (theres a plate with 4 mounting holes to the sub frame and a bracket with 4 mounting points. Those two items are then connected together with the bolt in question. )
The problem is when the upper mount is made it has 2 separate pieces that are molded together with rubber (vibration isolation), these 2 pieces are strong enough in design and they promised me that the whole design is "strong enough" for this car. The "PROBLEM" is in the molding process there is excess rubber that covers the actual mounting point on the upper bracket where the bolt threads in. this little bit of rubber (maybe 1/32th" thick) is now between the 2 mounting points. When the bolt is properly trqed this rubber is squished out slighty and stays in place. Well because the rubber is inbetween the 2 mounts it alows the motor to rocks a little. OVer time (not very much ) the rubber then squishes out and causes slop in the mount. With the power that the motor has it causes a rocking motion that alows the mount to shift for /aft within the bracket. The "Slop " gives enough play to make the 2 mounts act like a set of shears and if not fixed it can cause the bolt to shear off. (damn i hope this isn't to confusing)

In the end the fix is simple "so they claim". First support the enigne/tranny. remove the bolt and remove the upper mounting bracket. trim away the "excess rubber" where the lower mount would touch the upper mount. (its on the underside of the upper mount) reassemble and trq the bolt properly. this will eliminate the bolt was having any slop and stop it from breaking. It sounds good, whether its true, well i dunno time will tell.

I saw the new piece (damn i wish i had remembered my camera) and what they cut away. I also inquired about the bolt withe 8 stamped on it. i asked what grade it was. " its strong enough" was the comment i got back.
I then inquired about other failures and they do admit to having a few failures here and OVERSEAS, but claimed the simple fix they instructed is effective and works fine. They promised i should not have anymore issues with the current mount /bolt when properly installed. They also claimed they are looking into these mounts and will have a change made about the "excess" rubber thats in the upper mount.

FYI these guys were ok but not much fun to talk to. one engineer had just flown in and was obviously jet lagged, he also didn't speak much english AT ALL. the other guy seem to be a local rep for this region, his english wasn't much better. (spoke great japanese between themselves)

My car is already back together awaiting one part ,the BPV/diverter valve. it will be in tomorrow. WHile at the dealer they also investigated the issues about the P2006 code (that actuator thingy thats failing alot on CX-7's).

total bill isn't as bad as i thought. about 800.00 in parts, BUT this at warranty price which is 40% of retail value. So this little bolt caused close to 2000.00 worth of damage at consumer rates.

They still have yet to test drive the car to see if there was any other damage as the mechanic was done for the day. On the flip side i got a free roadside asst. bag and a first aid bag just from the dealer. Nice touch. rather have the MS3 CAI on the wall, but i'll get that soon enough.

The tech reps did take the broken andquestionable parts with them for more testing.

In the end it seems Mazda is starting to actualy look into this problem.
I will say this after seeing all the mounts and etc.. i can't understand the logic of have 4 mounting holes in the tranny and a plate with 4 mounting hole for the subframe, YET only having ONE bolt to connect the two. (dunno)

I'll get a detailed report on all parts broken and we'll see how long this "little fix" will last.

 

[maestro]

Nice bit of info. Thanks ^^

 

[bigtuna]

Just a tad bit exaggerated there Alejo, lol.

There are signs to listen for and I think that is what I will plan to do because if I go messing with that bolt I dont want for an slim chance for it to have been my fault.

I am do for the first oil change at about 3k so I have about another 1200k to go and I will talk to the tech again about there being another reported issue on the mount.

Just4banger make sure you are there when they call Mazda and report this so by time we get to the dealers and they call there is something on paper about it. That was my issue last time since they had no wind of any such problem. That was at 2 dealers as well that said the same thing.

Its kind of sad that you need to listen for something to go bump in the night instead of listening to the bose speakers. I think after reading all these posts I'm going to cancel my order. Mazda better not try to keep my 400 bux either. If they do, I'll be doing my best to bring this issue up to some level that will not be flattering to the mazda dealership. Pisses me off I really like the car, but I'm not going to own one if I have to be paranoid that the engine is going to fall to the ground while I'm going 80mph down the road. Even my 67 camaro in high school didn't do that when I broke motor/tranny mounts, and I broke several. They probably left out a cross member or safety catch just to speed up production slightly. What a bone headed decision!! Well, its going to cost them one sale at least.

 

[M3_Zoom]

UPDATE!!!!!!!!

In the end the fix is simple "so they claim". First support the enigne/tranny. remove the bolt and remove the upper mounting bracket. trim away the "excess rubber" where the lower mount would touch the upper mount. (its on the underside of the upper mount) reassemble and trq the bolt properly. this will eliminate the bolt was having any slop and stop it from breaking. It sounds good, whether its true, well i dunno time will tell.

I saw the new piece (damn i wish i had remembered my camera) and what they cut away. I also inquired about the bolt withe 8 stamped on it. i asked what grade it was. " its strong enough" was the comment i got back.
I then inquired about other failures and they do admit to having a few failures here and OVERSEAS, but claimed the simple fix they instructed is effective and works fine. They promised i should not have anymore issues with the current mount /bolt when properly installed. They also claimed they are looking into these mounts and will have a change made about the "excess" rubber thats in the upper mount.

In the end it seems Mazda is starting to actualy look into this problem.
I will say this after seeing all the mounts and etc.. i can't understand the logic of have 4 mounting holes in the tranny and a plate with 4 mounting hole for the subframe, YET only having ONE bolt to connect the two. (dunno)

I'll get a detailed report on all parts broken and we'll see how long this "little fix" will last.

Well I appreciate the update, but it still ticks me off. It seems to me that there taking the easiest and shortest route to "fix" the problem. Just like I originally said the engineerng of the mount sucks! If the mount was attached so the bolt fastened horizontally from front to rear, the bolt/mount would shift fore and aft with the engine torque. Sliding with it vice against it, it's not rocket science. Also instead of having two pieces of rubber matted together why not one solid piece? Did they happen to mention why its just a bolt and not a bolt/nut combination? There is so much weight relying on that bolt just "shaving the mount" doesn't do it for me. So now while they decide on what course of action will be the final say so, it's a matter of time before we hear about another victim.

We need someone to come out with a one piece urethane insert and be done with it or Mazda needs to reengineer the mount.

*edit* Does anyone know if the Speed6 folks have the same mount and or issue?

Again, thanks for the update.

 

[kokemon23]

Its kind of sad that you need to listen for something to go bump in the night instead of listening to the bose speakers. I think after reading all these posts I'm going to cancel my order. Mazda better not try to keep my 400 bux either. If they do, I'll be doing my best to bring this issue up to some level that will not be flattering to the mazda dealership. Pisses me off I really like the car, but I'm not going to own one if I have to be paranoid that the engine is going to fall to the ground while I'm going 80mph down the road. Even my 67 camaro in high school didn't do that when I broke motor/tranny mounts, and I broke several. They probably left out a cross member or safety catch just to speed up production slightly. What a bone headed decision!! Well, its going to cost them one sale at least.

This is obviously up to you, but just to clarify: there has not been a case yet (that I am aware of) where the engine actually falls to the ground. The mount breaks, everything sort of sinks/breaks, but the engine never comes out of the car. I've also heard many people be worried that this is going to happen when travelling high speeds on the highway, but that also hasn't happened yet. Everyone that I recall had theirs break at a relatively low rate of speed. Not saying this makes it ok or that it is nothing to worry about, just wanted to get the facts out there.

If you really are excited about getting the car, my advice is go for it. This is a relatively rare occurence, and the thing is a joy to drive. I agree that it is ridiculous that it's even an issue. What's worse is that apparently they have what they consider to be an easy fix for it, yet there is no recall or TSB yet. Good luck with whatever you decide.

BTW, love the screenname. The Office FTW!

justa4banger, thanks for the update!! Hope you get your car back soon in better than new condition.

 

[whitey4311]

I would still buy the car again I like it so much. I know what you are seeing on the internet is one thing and while it may be an issue it hasnt happened to the majority of us owners so thats something to consider.

I would check the build date on the car and get it some where starting in '07 to be sure you have all the new ECU updates ect. You could also make the sale hard for them and request the mount be checked and you be present when they "say" they will do this.

 

[M3_Zoom]

I would still buy the car again I like it so much. I know what you are seeing on the internet is one thing and while it may be an issue it hasnt happened to the majority of us owners so thats something to consider.

I would check the build date on the car and get it some where starting in '07 to be sure you have all the new ECU updates ect.

whitey4311, I certainly agree with you, I love the car and would definitely buy it again. Sure like any new car I expect issues, but one of this nature should not take so long to become a Recall or TSB. I just wan't to get over the worry of this possibly happening to me or anyone else for that matter. A quick and easy fix is a solid rubber insert vice the two that are claimed to shear the bolt in time. Even better would be a urethane mount and stronger bolt/nut combination and it's a done deal.

*If any of the forum Vendors read this, WE NEED A SOLID RUBBER OR URETHANE MOUNT!*

 

[TorqSpeed5252]

I'm not surprised the tech just told you "its strong enough" when you asked him what grade is was he probably has no idea what grade it is. I am going to the dealership tonight to buy a bolt. Tomorrow morning I am put it in the hardness tester here at work and then we'll know once and for all what grade it is. (There is a strong correlation betwen the strength of steel and its hardness)

If it's not at least a metric 10.9 / American grade 8 you vendors know what you need to do.