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BEWARE: Driveshaft kaboom from emergency auto-brake

Razorback007

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#21
You can't do that. It's missing the entire differential mount that the bolt is supposed to insert into. No way to add that without some serious fabrication. Just compare the pics of the one bolt subframe vs. the two bolt and you'll see what I mean.
Ok! That’s the answer… not the one I wanted to see, but definitely provided in a timely manner, Thanks!
 

TMac

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#23
If that's the "answer", someone asked the wrong question. FenFab does some trick work, but this.... Think about the differential movement under torque, then look at the design of this "brace".
 

Cdubya

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#24
Not so sure. If you look at some of the aftermarket rear differential braces for other vehicles with the same single, off-axis rear diff mount, some are just a rigid brace bolting the differential to the subframe.

BMW F series:
20200308_160849_1080x.jpg copy.jpg

350/370Z:
20201211_170724_740x.jpg copy.jpg 40435397_186657398793052_1346414544410378240_n.jpg P1000672 copy.jpg o6Jkeh6.jpg
 

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TMac

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#25
The bolts in the rear of the differential are to limit travel of the diff in the Z plane- up and down and may have some stabilization in the left to right motion. Under torque, as in a launch, the front of the differential where it connects to the driveshaft will move upwards, trying to rotate along the halfshaft/axle centerline in the opposite direction of the wheels. The rear of the differential will of course rotate downward.

Please point out to me how that "brace" will limit the rotation of the differential as the mount tries to counter the downward force. The only thing stopping it is the contact area of the two diff cover bolts- which are slotted!!! If that wasn't enough, the "isolator" (red part) should be used in compression and yet it would appear it's expected to work in tension? If this was designed to limit travel while traveling in reverse, then it' might have a chance. A simple pinion snubber would probably be a better alternative.
 

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GearHead_1

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#26
Under torque, the differential not only wants to tip the pinion upward but also wants to wind the diff clockwise. The red composite material would be compressed under torque if only one plane is considered. This axis seems to be what has been taken into consideration with this design, it does not seem to address the larger issue. Discounting the pinion wanting to move upward and dealing with only the rotational plane (you can't have one without the other) this design would work. How well? I have no idea.
 

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TMac

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#27
Any "clockwise" motion should be primarily handled by the front two mounts.
 

GearHead_1

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#28
It would be interesting to put a camera under each one of these designs and watch the differential and then compare.
 

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#29
Could be a waste of money if Ford is willing to exchange the proper rear frame for free.
 

GearHead_1

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#30
We could only hope.
 

Dale5403

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#31
Could be a waste of money if Ford is willing to exchange the proper rear frame for free.
We could only hope.
I seen on Facebook where a customer is working with his dealer trying to get the subframe on his switched to the 2 bolt. States his dealer agrees that it should be changed but they are waiting on an answer from Ford.
 

GearHead_1

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#32
There is only one point I'm trying to make here. Until I see vehicles released say after the first quarter of 21 show up with the more robust sub-frames installed I'm going to guess that Ford thinks the 1/3 bolt setup is good enough and has made it a running change.

I don't see Ford stepping up to the plate and making an across-the-board recall on this. If the later models are out there with the better unit we have something to go on. I would like to be wrong on that. I, along with just about anyone else with one of these wimpy setups would like to have this happen but I don't see it. Personally I feel cheated.

Does anyone out there with a late build date 21 have the 2/4 setup as manufactured? I haven't seen anyone claim to have this.
 

Cdubya

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#33
it would appear the only setup getting the two bolts are Aviators. I'm curious if MY2022 STs have the one bolt. We'll see once they come out. MY2022 Aviators seem to continue with the the two bolt even though the tow rating was downgraded. Perhaps Ford is betting the cost savings is well worth it even if they have to fix a hand full of failures. It's just sad. I feel bad for MY2021 ST owners and don't think I'd buy one knowing they cheaped out like that.
 

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#34
I wonder if the PIU still has the better subframe
 

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#35
it would appear the only setup getting the two bolts are Aviators. I'm curious if MY2022 STs have the one bolt. We'll see once they come out. MY2022 Aviators seem to continue with the the two bolt even though the tow rating was downgraded. Perhaps Ford is betting the cost savings is well worth it even if they have to fix a hand full of failures. It's just sad. I feel bad for MY2021 ST owners and don't think I'd buy one knowing they cheaped out like that.
Ford is being cheaper every year in certain areas, 2021 lost also small details that are useful from 2020 like the front washer. 2022 loosing the center console, some people might see this as a win but for leaving the SUV the same price? Makes you think what other small crap they're removing. Adding all the removed items that a MY20 had can get pricey out of pocket for those that want it.
 

Gantell

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#36
it would appear the only setup getting the two bolts are Aviators. I'm curious if MY2022 STs have the one bolt. We'll see once they come out. MY2022 Aviators seem to continue with the the two bolt even though the tow rating was downgraded. Perhaps Ford is betting the cost savings is well worth it even if they have to fix a hand full of failures. It's just sad. I feel bad for MY2021 ST owners and don't think I'd buy one knowing they cheaped out like that.
2022 STs have the One Bolt. Just picked it up from the dealer.

IMG_8883 (2).jpg
 

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#37
2022 STs have the One Bolt. Just picked it up from the dealer.

View attachment 8768
I'm just copying and pasting this from another thread that I typed it in..

"This just confirmed all of the research I did while working. Put my head together with my favorite parts guy.

My 2021 ST with a build date of March in Chicago.

My ST was BUILT with subframe part number: MB5Z-5035D ... I will get under my ST and find the part number hopefully on the subframe to confirm but that is the part that was used in my specific build at the Chicago plant.

That MB5Z-5035D subframe is for the 3.3NA hybrid motor for the Limited.

The correct subframe that my VIN number is calling for is MB5Z-5035E which is for the 3.0 Ecoboost.. hence this receipt confirming that part number as the one they replaced your old one with.

I have a printout of the part numbers used in my build and have it highlited next to what Ford actually calls for these vehicles. Next step is sending it to Ford to see if they will swap it out without any failures in mine yet.

Will keep everyone updated!"

PM your VIN number and I can check to see which part number they used on yours.
 

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#38
I have the 2021 and it is a one bolt as well.
 

GearHead_1

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#39
Wrong thread. Sorry.
 

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