GR Yaris DNA racing lower torque mount issue

Michael Knight said:
wow that does not look good. is the mount then too stiff or is the defect there due to previous bushing damage?
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I'm guessing the bushes broke first, and then the bolt that goes through the mount and into the chassis has smashed into the mount itself, since no bushes held it in place. Probably about the same time I realised something was not the way it should be😅. No damage on the bolt though.
 
I guess it's time for a final entry for me in the DNA torque mount saga, thank you for tuning in!

I ended up with all 3 black powerflex inserts, and I added them one by one over the past couple of weeks.

I started with the torque mount. Instantly car felt a lot better again after having driven with just the stock mount for a bit after the DNA broke.
It did add some NVH, probably a bit more than the fast road DNA mount, but nothing that bothered me. I was just glad to have a responsive car with tight shifts again.

Then last week I added the upper gearbox mount. This added a bit more NVH, but it did improve after 2-3 heat cycles. It can certainly still be felt at idle, but again, nothing that really bothers me. If you use this car as your daily commuter, then maybe it would start to bother you a little at this point. The tightness and responsiveness of the car improved, not as drastically as with the torque mount, but still a noticeable improvement.

Then today I added the upper engine mount insert. Honestly, a bit surprised with this one. It added no further NVH that I can tell, and the difference when driving isn't very noticeable either. I would say a slight improvement. However I guess it helps offload the stress from the other 2 mounts, so for durability it is probably worth it, and also quite easy to install.

The car now feels amazing to drive. The response on throttle and when shifting when you're on it is very direct. I also hope that all 3 inserts together offload some stress and that should hopefully help with durability of them.

The upper gearbox mount is by far the hardest one to fit, but if I can do it, then everyone can do it.

I don't regret going for the black ones, the NVH is really not that bad.

For reference I used these two videos to help me with the installs:

 
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While we're on this subject, the extra NVH can loosen stuff up. I was under the car today doing a check of all the bolts, bushings, looking for cracking things, etc., and found the main torque mount bolt a little loose.


All of the other mount bolts would "click" with the torque wrench set at the spec, but at 200nm, the main bolt turned about an eighth of a turn, meaning even break-away torque was less than spec. I assume that with the small contact surface area of the center compared to the stock one, along with the vibration has it move around just enough to lose a bit of tension. Not drastic, but still loser than it was 5,000km ago. Other than that, the bushing looks fantastic.
 

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sixtentouge said:
While we're on this subject, the extra NVH can loosen stuff up. I was under the car today doing a check of all the bolts, bushings, looking for cracking things, etc., and found the main torque mount bolt a little loose.


All of the other mount bolts would "click" with the torque wrench set at the spec, but at 200nm, the main bolt turned about an eighth of a turn, meaning even break-away torque was less than spec. I assume that with the small contact surface area of the center compared to the stock one, along with the vibration has it move around just enough to lose a bit of tension. Not drastic, but still loser than it was 5,000km ago. Other than that, the bushing looks fantastic.
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Just a little bit of Locktite perhaps?
 
sixtentouge said:
While we're on this subject, the extra NVH can loosen stuff up. I was under the car today doing a check of all the bolts, bushings, looking for cracking things, etc., and found the main torque mount bolt a little loose.


All of the other mount bolts would "click" with the torque wrench set at the spec, but at 200nm, the main bolt turned about an eighth of a turn, meaning even break-away torque was less than spec. I assume that with the small contact surface area of the center compared to the stock one, along with the vibration has it move around just enough to lose a bit of tension. Not drastic, but still loser than it was 5,000km ago. Other than that, the bushing looks fantastic.
Click to expand...
I need to get booked in at Toyota as mine still feels all loose down there. Gear change is kangaroo'ing 😬 ...my fault I've been putting it off, busy at work!
😵‍💫
 
sixtentouge said:
While we're on this subject, the extra NVH can loosen stuff up. I was under the car today doing a check of all the bolts, bushings, looking for cracking things, etc., and found the main torque mount bolt a little loose.


All of the other mount bolts would "click" with the torque wrench set at the spec, but at 200nm, the main bolt turned about an eighth of a turn, meaning even break-away torque was less than spec. I assume that with the small contact surface area of the center compared to the stock one, along with the vibration has it move around just enough to lose a bit of tension. Not drastic, but still loser than it was 5,000km ago. Other than that, the bushing looks fantastic.
Click to expand...

Good shout, makes sense. @Phil1291 had mentioned about a simple marking system to make it visibly obvious that sth has moved.

Also, I believe that in the instructions for fitment of parts like this, the last step is to check / retorque after driving a few hybdred miles/kms post-fitting. I think Whiteline may be mentioning it in the instructions for their inserts in the same area.

By the way, did we ever manage to get the exact official Toyota torque settings for the bolts of this part?
 
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Just did a check on mine, purple also. Seems OK, no visible damage, checked the inside of both rings, all good.
It was one of the first mods I did to my car, so I think it did at least 25kkm ~ 2 years.
 
Apart from @Phil1291 who made a good video on that subject, has anybody actually had issues with the center OEM lower torque mount rubber breaking / splitting before replacing it with an aftermarket one ?
Mine is vibrating on idle and gear shifting is becoming less precise.
Dismantled it, found it split roughly same as Phil. My engine is stock and I systematically use IMT for smooth down shifts...
Tomorrow having it checked / witnessed by Toyota for warranty replacement.
Then I will install the Powerflex insert in the new one to avoid / retard the issue.
 
Yeah Toyota kindly fitted my whiteline inserts as they agreed the bushing is weird as the new mount they ordered in for me came with holes/gaps in it and it's only a temporary fix as my issues came back 500 miles later so I need a full aftermarket torque mount to cure it and the other engine mounts uprated as the gear shifting is just not as good as it was from new. Really jerky at low speeds... it kangaroos while pulling away! o_O (n)
 
Just back from Toyota with good news.
After dismantling the OEM torque mount, they witnessed it was broken, as per other various pictures I showed them from other cars with same issue, took a picture, and readily inserted my Powerflex insert. They opened a warranty case to get a replacement. It is agreed as well that we will refit the Powerflex insert with the new mount to delay damage to the OEM rubber mount, if ever.
Also, other plan once new OEM torque mount received, is to check the two OEM top mounts, even if found OK will insert the Powerflex inserts to delay damage.
(y)
 
So, back from Toyota, checked & installed this new OEM torque mount under warranty.
HOWEVER... the new torque mount is exactly the same as the old "damaged" one, which shows that it is OEM built for that small F part of rubber to be disconnected from the aluminium support...
After installing the new one, even with the Powerflex yellow insert, still have those vibrations from idle up to around 2500 RPM...
So the issue is NOT from the OEM torque mount.
This is for information, the issue is probably coming from the right hand (RH, not LH) side engine mount. Refer to the Technical Service Bulletin CP-01014T-TME, Version 1, dated September 5th 2023 attached. spoke with Toyota, they say that the issue is not from the rubber engine mount itself, the TSB refers to the metal part between the chassis and the Engine mount.
This is next step investigation I will do with Toyota in the months to come.
Wil revert in due time.
 

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One year+ later.... Referring to the Technical Service Bulletin CP-01014T-TME, Version 1, dated September 5th 2023, once again, Toyota accepted to dismantle & check the Gear Box (Left Hand side) Engine mount and found the mount's center bolt loose and had ovalized the aluminium part, hence giving play to it all hence the vibrations. So warranty claim in progress, will be replaced on June 05th and my powerflex insert will be fitted back as well. In between time I had installed the powerflex insert on the Engine mount (RH side), (found no damage), which did reduce slightly or more precisely changed the feeling of the vibrations coming from the Gearbox damaged mount. So all should be back to normal June 05th onwards... That center bolt on the mount coming loose is only on some models, just random. So during install of the insert, (that center bolt has to be removed to seperate the two parts to push the insert in) I will add a drop of loctite thread stopper to prevent it coming loose ever again and torque to spec. End of story, I hope.
To be noted that the powerflex yellow inserts don't change the feel much from OEM, but rather strengthen and preserve the OEM bushings from flexing as much.
 
micsub said:
One year+ later.... Referring to the Technical Service Bulletin CP-01014T-TME, Version 1, dated September 5th 2023, once again, Toyota accepted to dismantle & check the Gear Box (Left Hand side) Engine mount and found the mount's center bolt loose and had ovalized the aluminium part, hence giving play to it all hence the vibrations. So warranty claim in progress, will be replaced on June 05th and my powerflex insert will be fitted back as well. In between time I had installed the powerflex insert on the Engine mount (RH side), (found no damage), which did reduce slightly or more precisely changed the feeling of the vibrations coming from the Gearbox damaged mount. So all should be back to normal June 05th onwards... That center bolt on the mount coming loose is only on some models, just random. So during install of the insert, (that center bolt has to be removed to seperate the two parts to push the insert in) I will add a drop of loctite thread stopper to prevent it coming loose ever again and torque to spec. End of story, I hope.
To be noted that the powerflex yellow inserts don't change the feel much from OEM, but rather strengthen and preserve the OEM bushings from flexing as much.
Click to expand...
yeah, it is what I did (loctite and yellow inserts all around) to fix troubles with shifting and loosening bolts over and over again.
it is funny, like recently I watched a hagerty vid on YT visiting the GR factory, meeting all the brightest heads from management and engineering, and how they incrementally are refining the GR cars and yada yada, but they all stubbornly refuse to fix the obvious and notoriously known weak points of our cars...
 
Today was the day when at last Toyota replaced the Gearbox mount with the new improved one.
Obviously when dismantling the old gearbox mount, the center bolt was found loose and the hole in the aluminium part had been ovalized, so even when retightened, didn't help much.
For info, the old mount's center bolt was diam 8, the new improved part this bolt has become diam 12, and torqued at 110 Nm (plus a drop of thread lock ofcourse) and powerflex yellow insert installed at the same time.
Full guarantee, nothing to pay. (The part costs 420 € ! + 2 hours work).
End of story.
 
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