Product proposal- D90 Melting Mudflap fix

[Toxic_Avenger]

Those with a defender 90 may be aware of the problem whereby the factory fitted LHS rear mudflap can melt over time due to hot exhaust gases. This problem is a combination of poor design, where the mudflap can flex into the exhaust gas stream when travelling at speed, eventually causing an unsightly burn mark. I had come up with some ideas of my own to prevent the early demise of my mud flaps, but found inspiration from Shatkins on this forum who made a similar design for his 90. After some discussions, he was happy to allow me to tweak his design for the masses to help prevent this recurring problem.

I am putting forward an expression of interest for a limited production run of stiffening brackets to work in conjunction with the factory mudflap hardware and mounting bracket. The product would be produced from ~3mm CNC Plasma cut aluminium, and would be suitable for the factory fitted 'Puma' Defender 90 rear LHS mudflap.
Depending on interest I could also look at compiling a kit to allow the mudflap to be converted into a 'quick release' setup, which would alleviate the other problem with the factory design- The mudflap is easily pressed into the tyre when offroad, and is easily plucked off. This mod would allow defender drivers to easily remove their rear mudflaps when the risk of damage is present.

Please express your interest below, and I can gather a more accurate idea of product costing once I put the design out to tender to my fabricators.

I've done some messing about in Sketch-up, and spent some shed time with some sheet steel, so here is a bit of an idea what the finished product may look like:

http://www.aulro.com/afvb/attachment.php?attachmentid=105915&stc=1&d=1455956406

https://www.aulro.com/afvb/

(Obviously this will have holes for mounting and will be installed on the other side of the mud flap). You would be required to drill 2x M8 holes thru the lower part of your mud flap to secure the bracket, but otherwise this will be a unobtrusive and practical modification.

OK, Go.

[parallax]

Would you make a similar plate for the RHS? Purely aesthetic really.

Regardless, put me down for one!

[Toxic_Avenger]

I could but it would not serve any purpose at all other than extra weight, and the different amount of deflection at speed (which you don't see in the driver's seat anyway!).

For lolz, you could stick a few of these on the RHS in the same loaction as the fasteners on the LHS
https://www.aulro.com/afvb/images/imported/2016/02/232.jpg

I would!

[barkingmad]

Depending on cost I might be interested. Mine is starting to show some signs of damage after 5k.

[Pickles2]

Looks very professional.
A couple of questions.
Could it placed on the inner face of the mudflap, facing the rear wheel),...it would then not be visible?
So, this plate is affixed to the mudflap, not the bracket?...so mudflap can still move if it hits something etc. (no strain on bracket)
I note that the edge of the flap is still visible,....this usually attracts the heat more than any other part.
No negativity here, just questions!!!....So thank you for your efforts.
Thanks, Pickles.

[Toxic_Avenger]

Roll Up, Roll up to the Toxic Avenger's side show!


Looks very professional.
Why thank you sir!


A couple of questions.
Questions are appreciated- they all help to clarify the design and assist with the Go/No-Go of this project


Could it placed on the inner face of the mudflap, facing the rear wheel),...it would then not be visible?

I'm glad you asked.
As above:



http://www.aulro.com/afvb/attachment.php?attachmentid=105916&stc=1&d=1455956503

(Obviously this will have holes for mounting and will be installed on the other side of the mud flap). You would be required to drill 2x M8 holes thru the lower part of your mud flap to secure the bracket, but otherwise this will be a unobtrusive and practical modification.



So, this plate is affixed to the mudflap, not the bracket?...so mudflap can still move if it hits something etc. (no strain on bracket)
The 'device' will affix to both the bracket AND the mud flap. The goal here is to prevent the mudflap from flexing into the exhaust to begin with. So making extra holes and attaching to the mudflap without being in contact with the bracket may not change the final outcome of melting rubber.
I don't foresee the factory bracket bending under normal use (yes it will get extra strain in a deep water crossing for example, but this is why quick release may be valuable for some users. Similarly, Aluminium will deform in preference to the steel, so material choice comes in here. If bracket damage it becomes a problem, I've got the plans for a bracket that could be made out of 5mm plate, and the car would crumble around it :twisted:
The idea is to have something that wil prevent damage in the urban jungle, while offroad, preferably one would run without mudflaps to prevent damage.


I note that the edge of the flap is still visible,....this usually attracts the heat more than any other part.

I've given this some thought. The goal here is to stop the mudflap flexing where the bracket is affixed. So in theory, the mudflap should not be anywhere near the exhaust in any normal driving situation. Having it approx 5mm narrower than the exhaust cut-out means it is less visible from behind while installed.

[filcar]

... The goal here is to stop the mudflap flexing where the bracket is affixed. So in theory, the mudflap should not be anywhere near the exhaust ...


Does the theory work as in has a prototype been tested? Onto my third mudflap and looking for a solution. If the theory is sound I am interested.

[Avion8]

What is the problem with Shatkins solution. It seems to address the problem & is quickly removed. I have the makings of his solution in the shed, & am just waiting for my dealer to provide a new mudflap! My temporary solution with a slightly different cut removing the dripping molten portion and bonding pinch weld has held up well the past 2000kms, but it is not the original mudflap pattern.:(

[YOLO110]

This looks like a good fix to the problem.

However, without wanting to spoil the idea, I decided to go back to look at the main cause of the melting mudflat, as mentioned the very hot exhaust gas blowing against the flap as it blows up with speed.

I decided on another fix.. I went to my local specialist exhaust shop and had them add a 8cm extension to the exhaust pipe! This puts the exhaust exit behind even a mud flap angled up at 45 degrees... all the hot gasses always exit behind the mudflat now!

I have driven over 1000km with no issues since doing the mod! The only visible difference is the exhaust sticks out more, but you soon get used to that.

The fix cost me $60 bucks work from my exhaust shop.

I have photos, but hopefully the description will suffice. Having said all of this, I would probably still add this suggestion to my fix... then I will hopefully be totally melt free!

Cheers,

Peter.

[JDNSW]

Is this modification likely to ultimately result in a fatigue failure of the attachment bracket due to the increased bending load?

John

[Toxic_Avenger]

Is this modification likely to ultimately result in a fatigue failure of the attachment bracket due to the increased bending load?

John
Hi John, I'll answer that with "Potentially".
Anything's possible. Keep in mind we are talking about press bent 2mm steel, so there would be some degree of work hardening in the mechanical bend to begin with. Could this propegate to a fatigue crack / failure long term? I can't say. If I were to guess, in 'extreme' situations (Think plowing thru dense fluids like water, snow, or digging the mudflap into deep sand), the bracket WILL bend- this is a given. To a greater degree, the nutserts would pull out of the chassis crossmember, but I'm just spitballing.

If your actual question is 'Have I calculated the risk of fatigue failures of the bracket with the mudflap stiffening plate'? No.
'Have I the means to calculate this'? No.

I did some back of the cocktail napkin sums here (http://www.aulro.com/afvb/90-110-130-defender-county/197704-meet-my-90-share-adventure-5.html#post2462429) (which are probably wrong), but give a very rough idea of the forces at play. I don't think normal on road driving will pose a significant risk to the design of the proposed fix, or the factory bracket. Biggest risks would be water, snow, sand or backing into a really high gutter.

I'm happy to have someone run some sums if they are in a position to do so, but I'm not looking to throw $10K in engineering consultancy fees to deconstruct and critically analyse life, the universe and everything else, for a part which is essentially just a small run.
What I'm aiming to do (and most business people will understand) is make use of the economies of scale to get a product to those who want it at the best possible rate. Materials wise, It's cheaper, per unit, for me- and everyone else for that matter- to make a batch of 15 from a whole sheet than it is to get my plans cut on a unit-by-unit basis.

There's more than one way to skin this cat:
1) Side exit exhaust- permanent, and against ADR's
2) Extended exhaust - permanent, still has the potential for contact of mud flap against hot metal pipe
3) Run no mudflaps - temporary, but illegal (against ADR's)
4) Run a bolt on bracket like I proposed above- temporary, but potential for damage offroad or long term. Damage can be mitigated by running as a 'quick release' setup

So it's all a game of chance, which way people decide to go is up to them, but the offer is here if anyone wants to jump aboard. I think there's enough transparency above to help people make a decision?

I welcome any further suggestions, ideas and feedback :)

[Pickles2]

Toxic, very good thread mate.
Would there possibly be an easier "fix"?
I was just looking on another thread where someone was talking about heat/exhaust insulation,....would there be a self adhesive, or glueable heat shield type material that one could simply affix to the rear of the mudflap & curl/shape it around the mudflap cutout? It would then not be seen, & if such material is available, maybe the problem would be solved.
Pickles.

[Larry]

Toxic, very good thread mate.
Would there possibly be an easier "fix"?
I was just looking on another thread where someone was talking about heat/exhaust insulation,....would there be a self adhesive, or glueable heat shield type material that one could simply affix to the rear of the mudflap & curl/shape it around the mudflap cutout? It would then not be seen, & if such material is available, maybe the problem would be solved.
Pickles.

After my 3rd mud flap started melting (first two replaced under warranty), I just added a small piece of aluminium angle to the top & rear of the rubber, with a flat piece at the front.

Been on for several months now with no further melting.;)

Sorry, didn't mean to hijack the original thread.:)

[rangieman]

After my 3rd mud flap started melting, I just added a small piece of aluminium angle to the top & rear of the rubber, with a flat piece at the front.

Been on for several months now with no further melting.;)

Sorry, didn't mean to hijack the original thread.:)

Yep and why make something so simple so complicated:thumbsup:
That is exactly the fix i was thinking of when i started to read this thread and no offence to the Op;)

[Toxic_Avenger]

None taken Rangieman!
I'm all about finding the best way to fix this problem that affects us 90 owners.
Putting the question to the masses helps us all find the best solutions, which is a win for all IMO.