DCT Access Plate - Engineers ?
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,476
Likes: 711
From: Sausalito CA
DCT Access Plate - Engineers ?
Why did GM not place a hole or an access panel in the shear plate, like it did for the oil filter, for the DCT filter?
My conspiracy theory is to increase dealership profits
I have not read any co-members mention any shear plate cracking, flex, or handling negatives so
I sure would be tempted to DIY an access panel, yet my question....
Are there any engineers here who can comment on the reason not to install this DCT filter access panel?
My conspiracy theory is to increase dealership profits
I have not read any co-members mention any shear plate cracking, flex, or handling negatives so
I sure would be tempted to DIY an access panel, yet my question....
Are there any engineers here who can comment on the reason not to install this DCT filter access panel?
Le Mans Master
Joined: Feb 2009
Posts: 5,169
Likes: 199
From: Your Sister's Bedroom
Why did GM not place a hole or an access panel in the shear plate, like it did for the oil filter, for the DCT filter?
My conspiracy theory is to increase dealership profits
I have not read any co-members mention any shear plate cracking, flex, or handling negatives so
I sure would be tempted to DIY an access panel, yet my question....
Are there any engineers here who can comment on the reason not to install this DCT filter access panel?
My conspiracy theory is to increase dealership profits
I have not read any co-members mention any shear plate cracking, flex, or handling negatives so
I sure would be tempted to DIY an access panel, yet my question....
Are there any engineers here who can comment on the reason not to install this DCT filter access panel?
Personally I find the 2 minutes it takes to remove it to not be worth cutting it up. Life gets a lot easier if you replace the goofy E16 bolts with normal flange heads.
Race Director
Joined: Aug 2016
Posts: 12,709
Likes: 10,135
From: Garden Valley CA
It is a shear plate so by definition it carries a structural load and putting another hole it reduces its load carrying capability, especially when that hole is put adjacent to another hole. Notice that the engine oil change hole is oblong to distribute the loads around the hole. If the structural engineers had their way there likely wouldn't be any holes in the plate. If it wasn't intended to carry structural loads they would have just installed a plastic cover. To quantify the reduction you would need to do an analysis and know what loads are being transferred but it is unlikely the average Corvette driver would notice the difference during normal street driving. And yet some people will also buy a cross brace to stiffen up the chassis.
I have a lift and the proper tools so removing and reinstalling the shear plate doesn't take much time. And since I don't track my car it only needs to be removed once every few years.
I have a lift and the proper tools so removing and reinstalling the shear plate doesn't take much time. And since I don't track my car it only needs to be removed once every few years.
Last edited by RKCRLR; Mar 8, 2026 at 11:23 AM.
Drifting
Joined: Aug 2022
Posts: 1,875
Likes: 782
From: Stamford, CT
They could have added that support in other ways, no?
It is a shear plate so by definition it carries a structural load and putting another hole it reduces its load carrying capability, especially when that hole is put adjacent to another hole. Notice that the engine oil change hole is oblong to distribute the loads around the hole. If the structural engineers had their way there likely wouldn't be any holes in the plate. If it wasn't intended to carry structural loads they would have just installed a plastic cover. To quantify the reduction you would need to do an analysis and know what loads are being transferred but it is unlikely the average Corvette driver would notice the difference during normal street driving. And yet some people will also buy a cross brace to stiffen up the chassis.
I have a lift and the proper tools so removing and reinstalling the shear plate doesn't take much time. And since I don't track my car it only needs to be removed once every few years.
I have a lift and the proper tools so removing and reinstalling the shear plate doesn't take much time. And since I don't track my car it only needs to be removed once every few years.
Race Director
Joined: Aug 2016
Posts: 12,709
Likes: 10,135
From: Garden Valley CA
Like a cross member or perhaps a thicker ridge in the shear plate itself, it would have added a bit of extra weight but it would have made DCT maintenance simpler and cheaper. The dealer charges 3 hrs labor for the filter change. Mainly for the shear plate shenanigans.
If I was going to make an access opening in the shear plate I'd make a closeout plate with a lap joint to act as a mini shear plate to transmit the loads across the opening. I'd use something like Click Bond nuts on the back side of the shear plate and enough fasteners to get a good clamping force on the closeout plate. Yes, you would still have to remove some fasteners but they would be fewer, the same size, and close together.
Last edited by RKCRLR; Mar 8, 2026 at 12:42 PM.
Drifting
Joined: Mar 2020
Posts: 1,568
Likes: 1,022
From: 31 hours East of Peoria, AZ
The plate is a stress member. A 90° corner in the access hole will create a stress concentration that would have the hightest chance of causing a stress crack. If a hole is made, rounded "corners" or an oval shape would be best.
The other aspect of this that may have percipitated the creation of an access hole is the use of the wrong kind of Torx bit to remove many of the bolts. There are many videos / images out on the internet indicating the use of a 16 mm Torx socket which is the wrong one to be used causing a greater chance of stipping the heads (I know of one fellow locally who had three of them strip).
The correct socket is a 14mm External Plus (EP) Torx socket.
The other aspect of this that may have percipitated the creation of an access hole is the use of the wrong kind of Torx bit to remove many of the bolts. There are many videos / images out on the internet indicating the use of a 16 mm Torx socket which is the wrong one to be used causing a greater chance of stipping the heads (I know of one fellow locally who had three of them strip).
The correct socket is a 14mm External Plus (EP) Torx socket.
Drifting
Joined: Feb 2023
Posts: 1,353
Likes: 1,115
The access cutouts for the engine oil filter and drain plug have a radius in the metal to distribute loads to prevent cracks from developing. I have not, nor do I intend, to cut a hole in the shear plate which, when bolted in place, is a stressed structural member of the chassis. I’m not dropping the plate every day. Removing it to change my DCT filter every now and then is an inconvenience I can put up with. Plus, with the plate out of the way, I can easily inspect the engine, trans, axles for leaks or damage.
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Safety Car
Joined: Jun 2008
Posts: 3,798
Likes: 5,860
I hate how modern cars all have some cover under them. Its an extra pain in the ***.
But, I'd rather remove them and take the chance to inspect everything, check for leaks, etc than have another access hole. The covers can hide simple issues until they turn into a huge mess.
But, I'd rather remove them and take the chance to inspect everything, check for leaks, etc than have another access hole. The covers can hide simple issues until they turn into a huge mess.
Thread Starter
Le Mans Master
Joined: Oct 2000
Posts: 6,476
Likes: 711
From: Sausalito CA
Thank you all, great discussion.
Seems a square hole would be, dare I say, risky, with an oval hole the better option.
Yes, with the proper tools, ie: a tall lift, not a Quik Lift, shear panel removal is much easier.
Even if shear panel removal is a yearly "adventure", not modifying is GM's engineering thinking, I could live with that.
If I choose to modify, an oval or radius cut hole, with a lap joint, ridge, or mini X-brace, perhaps, as this reads like
exceptional advice.
PS oil level check or adding/ replacing fluid, I did not think that so burdensome if going through the driver side rear wheel well to access the level check bolt.
Perhaps, I am missing "something".
Seems a square hole would be, dare I say, risky, with an oval hole the better option.
Yes, with the proper tools, ie: a tall lift, not a Quik Lift, shear panel removal is much easier.
Even if shear panel removal is a yearly "adventure", not modifying is GM's engineering thinking, I could live with that.
If I choose to modify, an oval or radius cut hole, with a lap joint, ridge, or mini X-brace, perhaps, as this reads like
exceptional advice.
PS oil level check or adding/ replacing fluid, I did not think that so burdensome if going through the driver side rear wheel well to access the level check bolt.
Perhaps, I am missing "something".
CF Community Team
Joined: Nov 2005
Posts: 5,148
Likes: 2,804
From: Charlotte N.C.
The dealers tech stripped the heads on more than a couple of mine when they did the filter (I found it when I did the drain and fill). While it's real easy to see into the fill hole through the wheel well and add fluid with a clear tube and funnel I'm not sure it would be easy to remove and replace the cap that way.
Burning Brakes
Joined: Nov 2022
Posts: 1,046
Likes: 1,108
From: Western Mass
The dealers tech stripped the heads on more than a couple of mine when they did the filter (I found it when I did the drain and fill). While it's real easy to see into the fill hole through the wheel well and add fluid with a clear tube and funnel I'm not sure it would be easy to remove and replace the cap that way.
