Underbody panels tearing off

[AlexM]

[mod note: this post was originally a reply in Mike's rust-proofing thread]

This past weekend I backed over a curb, and as the rear wheels dropped down, the rocker panel just in front of the rear wheels hit the curb. This caused the plastic trim to bend at a sharp angle, and also snapped off some of the retaining clips and screws. It doesn't look like there was any damage to the metal under the plastic. I am trying to avoid taking this into a body shop to have it repaired, as it seems like it should be a DIY type project. I just need to order the replacement part from Tesla.

I don't have a lift system like you have, but was hoping that would be necessary to work on this piece. What are your thoughts on removing and replacing this trim piece while the car is on the ground?

Any other tips that you can suggest would be appreciated.

thanks.

 

[Mesprit87]

Welcome to the forum!

If I may,

The lift or any lifting device is not needed to replace this part. In fact I had get the car off the lift to remove it.
As mentionned earlier, it just a question of popping covers in the inside of the rocker trim (4 hinged covers but mine had only 2 bolts installed ), removing the bolts (10mm), removing the push pins at both ends and then pop the part out of the rocker using the tool Mike mentionned or somekind of plastic scraper and a flat screw driver. You have the chance to practice on a scrap part
Good luck

 

[Mike]

Thanks for this post. It is very helpful for my current situation:

This past weekend I backed over a curb, and as the rear wheels dropped down, the rocker panel just in front of the rear wheels hit the curb. This caused the plastic trim to bend at a sharp angle, and also snapped off some of the retaining clips and screws. It doesn't look like there was any damage to the metal under the plastic. I am trying to avoid taking this into a body shop to have it repaired, as it seems like it should be a DIY type project. I just need to order the replacement part from Tesla.

I don't have a lift system like you have, but was hoping that would be necessary to work on this piece. What are your thoughts on removing and replacing this trim piece while the car is on the ground?

Any other tips that you can suggest would be appreciated.

thanks.

Cheers @AlexM and sorry to hear about your mishap.

The info @Mesprit87 just posted to you is correct, no need for the vehicle to be off the ground for this part to be swapped out.

If able, post an after shot for us.

 

[Mike]

Thanks for this post. It is very helpful for my current situation:

This past weekend I backed over a curb, and as the rear wheels dropped down, the rocker panel just in front of the rear wheels hit the curb. This caused the plastic trim to bend at a sharp angle, and also snapped off some of the retaining clips and screws. It doesn't look like there was any damage to the metal under the plastic. I am trying to avoid taking this into a body shop to have it repaired, as it seems like it should be a DIY type project. I just need to order the replacement part from Tesla.

I don't have a lift system like you have, but was hoping that would be necessary to work on this piece. What are your thoughts on removing and replacing this trim piece while the car is on the ground?

Any other tips that you can suggest would be appreciated.

thanks.

PS, I took another look at your damage:

If it was my car, I would apply some sort of anti corrosion gel/spray on what looks like the exposed primer (inside red ovals) prior to putting the new trim part in place.

If that is just salt spray, then no real issue.

But if the paint has cracked and flaked off and that is bare metal, I would hit it with some rust-paint before adding rust spray.

 

[JWardell]

I've seen mention here and there of the panels under the car coming off (or the rear bumper) but no threads dedicated to it.

Today I noticed something hanging under my car and it turns out a piece of one of my panels had torn off most of the way and was now folded back and dragging. I had no choice but to finish the job and tear it off, and now you can see HV wiring and drive unit connections are exposed. Hopefully this is not large enough to be an issue (yet).
I'm shocked to see this is made of a soft fabric-like fiberglass material that is even more pathetic than plastic. I had a long drive in the heavy rain last night that might be the culprit though I did not go through any standing water. See my photos below of the piece and the hole...not sure if I'm missing a bolt or not (and what is circled in white?)

I'm hoping others can share their similar experiences and possible solutions. I would love to see more durable replacements. Of course most cars have issues with the front panels hitting curbs etc, but the 3 is already infamous for rear bumpers being torn off, especially after this fiber panel disintegrates.

Here's the article on InsideEVs about the bumpers falling off:
https://insideevs.com/tesla-model-3-rear-bumper-rain/

It includes a video of the underside showing the various panels.

 

[FRC]

That is easily the most disturbing structural fault I have seen to date. Please keep us informed regarding any action taken by Tesla. Thanks.

 

[garsh]

That is easily the most disturbing structural fault I have seen to date.

It's not structural. That panel is just for aerodynamics.

It should be easy to have it replaced.

 

[FRC]

It's not structural. That panel is just for aerodynamics.

It should be easy to have it replaced.

I was ineloquent. I didn't mean structural in that way. I meant a necessary physical part of the vehicle. The fact that it tore off in this case exposing vital components is disturbing to me. I'm certain it's easily replaced, but is it adequate to stand the test of time?

 

[GDN]

Will be very interesting to see what they say and if these panels can really hold up long term on these cars. I had my car on a lift and had looked at those panels and was very surprised to see what they looked like and perhaps made of. It's easy to see they are critical for aerodynamics. I would have thought a heavy duty thick plastic would have been better with some drain holes.

 

[NYer]

I've seen mention here and there of the panels under the car coming off (or the rear bumper) but no threads dedicated to it.

Today I noticed something hanging under my car and it turns out a piece of one of my panels had torn off most of the way and was now folded back and dragging. I had no choice but to finish the job and tear it off, and now you can see HV wiring and drive unit connections are exposed. Hopefully this is not large enough to be an issue (yet).
I'm shocked to see this is made of a soft fabric-like fiberglass material that is even more pathetic than plastic. I had a long drive in the heavy rain last night that might be the culprit though I did not go through any standing water. See my photos below of the piece and the hole...not sure if I'm missing a bolt or not (and what is circled in white?)

I'm hoping others can share their similar experiences and possible solutions. I would love to see more durable replacements. Of course most cars have issues with the front panels hitting curbs etc, but the 3 is already infamous for rear bumpers being torn off, especially after this fiber panel disintegrates.

Here's the article on InsideEVs about the bumpers falling off:
https://insideevs.com/tesla-model-3-rear-bumper-rain/

It includes a video of the underside showing the various panels.

View attachment 19964 View attachment 19965

I hope that my clean vehicle is not made of asbestos... Why the hell would they design in a fibrous textile as an external component?

 

[MelindaV]

I hope that my clean vehicle is not made of asbestos... Why the hell would they design in a fibrous textile as an external component?

Asbestos has been banned in the US since 1989.
6 months ago EPA removed some of those regulations, but would have no reason to expect this fiberglass material has any asbestos at all. are you seeing something that would lead you to believe this has asbestos? have you had it tested?

 

[SoFlaModel3]

Please keep us posted!

 

[NYer]

Asbestos has been banned in the US since 1989.
6 months ago EPA removed some of those regulations, but would have no reason to expect this fiberglass material has any asbestos at all. are you seeing something that would lead you to believe this has asbestos? have you had it tested?

No, but when I see a fibrous material, it comes to mind. I would expect it to not be asbestos, but perhaps a fibrous composite like carbon infused in some sort of epoxy. But when I see fibrous material in a rough working environment, it concerns me.

 

[msjulie]

I've seen what looks like that material in cars before; I feel like something must have impacted the car to tear it like that as otherwise it shouldn't be subjected to too much actual stress

 

[FRC]

I've seen what looks like that material in cars before; I feel like something must have impacted the car to tear it like that as otherwise it shouldn't be subjected to too much actual stress

Doesn't appear to me that it is the type of material that would hold up well long term under the car in rain, snow, salt, and slush. But, hey, what do I know?

 

[GDN]

Does anyone know what is under the S and X? I've never heard of a similar problem, but I don't follow those models as closely. If it is the same product, I'd say it is likely tested with time.

 

[JWardell]

I've seen what looks like that material in cars before; I feel like something must have impacted the car to tear it like that as otherwise it shouldn't be subjected to too much actual stress

I would say it is similar to material commonly use in wheel wells now, but shocked to see it hanging on the bottom of the car where things can easily kick up.
The tear started at the leading edge of the panel, where it didn't need an impact, just a bit of a sag over time, then catch air and water to quickly pull more then tear it away from the few bolts holding it.
It's pretty easily torn by hand. Definitely fibers in epoxy with a felt like feel to the outside.
I haven't even had a good snow yet, which I assume chunks of snow and ice will obliterate this stuff quickly. Hopefully I can wait till spring to get it replaced, if only Tesla were to have an improved plastic replacement.
Or better yet, and aftermarket titanium version!

 

[Bokonon]

Does anyone know what is under the S and X? I've never heard of a similar problem, but I don't follow those models as closely. If it is the same product, I'd say it is likely tested with time.

I believe the Model S and X have titanium deflectors and underbody shields, unless that has changed in recent years. They added these shields after a couple of incidents in 2013 in which road debris managed to puncture the battery pack.

https://www.tesla.com/blog/tesla-ad...-shield-and-aluminum-deflector-plates-model-s

The first of the three shields is a rounded, hollow aluminum bar that is designed to either deflect objects entirely or, in the case of a self-stabilizing, ultra high strength object, like a three ball steel tow hitch, absorb the impact and force it to pike upwards well forward of the battery pack. This pierces the plastic aeroshield and front trunk liner, but causes no damage affecting safety and the car remains in control and driveable before, during and after the impact.

This is followed by a titanium plate, which has exceptional strength-to-weight properties and is more commonly seen in aerospace or military applications. The titanium plate prevents sensitive front underbody components from being damaged and aids in neutralizing the road debris.

By this point, the vast majority of objects will have been deflected or crushed. For the rare piece of debris that remains intact, we added a third shield, which is a shallow angle, solid aluminum extrusion that further absorbs impact energy, provides another layer of deflection and finally causes the Model S to ramp up and over the object if it is essentially incompressible and immovable.

 

[GDN]

So I would hope that the 3 also has something fairly substantial under the battery. Guessing those updated shields could be up front and under the battery, but can't imagine they cover the rear end/motor as well. Don't know for sure. Will be interesting to see how this plays out and how this material holds up long term.

 

[JustTheTip]

Someone needs to make aluminum undertray replacements. Had one on my Infiniti and it was great. Sure, there’d be added weight, but it would offer a lot more protection.