Many 4.2L J-gate shifter surrounds have sharp, peeling chrome caused by normal movement of the shift lever. Unfortunately, I couldn't find a separate replacement part just for that chrome J trim, and the only OEM replacement part is the entire surround, which is very expensive - and will fail again because the design using chrome plating is not durable. That J trim should have been stainless steel.

I'm not an engineer, but it seems to me that a 1-piece custom overlay that replicates the original shape and simply fits over the damaged J chrome could be an affordable and easy DIY fix. It could be affixed with 3M automotive tape, if necessary.

Does anyone on the Forum have, or know someone who has, the ability to create a prototype overlay using 3D printing? If it works, the next step would be to find a fabricator who could produce them in stainless steel or other durable material at a reasonable cost. Is there a Forum Sponsor who can help?

I'd like this thread to (1) find a source and (2) determine owner interest. So, if you can help identify a 3D printer and/or fabricator or have peeling trim, speak up.

 

Mine is peeling, and I will be fixing it one way or another in the future.

 

From a machinists perspective, that's a very difficult part to fabricate. I think you'd have better results die stamping aluminum and adhering it to the base plastic but dies are very expensive to make plus aluminum is fickle. Doing SS is a whole 'nother batch of troubles.

Then there's the whole deal with the black pealing on some shifters I've seen. How do you correct that?

 

Not to jinx myself, but my nearly 10 year old car does not have this problem, however the Super V8 did inside the gate in a small piece just after a few years. Guess it is luck of the draw. I think there are only 2 solutions, either a new one/breakers sourced or fabricate a completely new assembly.

 

Thanks for your thoughts. Apparently those fabrication difficulties are why there's no overlay available on the aftermarket. Your knowledge and experience is a real asset to this Forum.

After seeing TV reports of various custom prosthetic devices quickly and economically produced using 3D printing, I thought it might be possible to do the same for this overlay.

Fortunately, the black portion of mine is still ok and only part of the inside edge of my J-gate chrome is peeling. I noticed it early enough to stop it from getting worse by applying a thin layer of clear epoxy to that edge with a toothpick. But I'd still like to fix it.

 

Aha - the quest for the Holy Grail ....
I am constantly looking for a solution for this problem, so you can count on my order if you do manage to come top with an answer.

Geoff

 

My son is an engineering student and has access to many 3D printers. If you want to make the .stl file available I can get a prototype print done. If this is a common problem I will have something fabricated and make available. My XKR has the same issue and I am looking for a fix also.

 

What's the quality on 3d print? Is it high enough that the material can be polished or have a chrome finish? I haven't seen anything that high quality. If you're talking a .015"-.030" thick form fitting chrome finish I don't think 3d print will do it.

I'm actually curious how the OEM made them. The black section seems to be similar material to the chrome (thin wafer of printed metal / plastic adhered to a plastic casting). I wonder if the original finish was applied to the casting as a built up material is applied like a 3d 'decal'. I'm fascinated by stuff like that...

If I were to repair mine I'd start with a chrome vinyl tape and apply it with care and see how durable and well it looks. Or I'd scrap the chrome look and go with some flavor of painted finish where the chrome was.

 

Forget 3D printing, someone needs a CNC and some aluminum billet...

 

On my XJ it was real metal plate cast over plastic just like what they use on interior chrome door releases I know because I cut myself on it and a small bit came off.

 

As I said in my original post, I'm not an engineer (or machinist, or anything else) who can offer any insight into how to make this overlay. Nevertheless, I am encouraged by the responses so far and hope that brainstorming on this thread will lead to a solution.

Note to J5hort: What is an .stl file? (P.S. - I Googled it and understand). Since your 2008 XKR has the same issue, can you provide your son with whatever he needs to 3D print a prototype?

Ranchero50's comment about chrome vinyl tape made me think about the aluminum tape that HVAC installers use to seal ductwork. I think I have some that was left over when we had new systems installed a few years ago and will give it a try if I can find it.

Maybe a 3D prototype can be used as a die or mold to produce what we need.

Lots of experience on this Forum. Where there's a will there's a way. Necessity is the mother of invention.

 

I agree with jahummer - chrome plated plastic. I got cut, too. That's why I covered the rough edges with clear epoxy.

 

We are printing at .20mm typically. There is the option to print at higher resolution, but depending on material, extrusion issues present themselves. The idea was to create a physical prototype and have it mass produced. That is what 3D printing is best for. It is possible to print metal and we are converting one to a CNC engraver. This would work for producing a metal piece. In any event some finishing and polishing would be in order.

 

That's great news!

 

The design will need to be obtained or created, sliced, then printed. The design work is the hard part. May be able to do from a picture. Maybe use a flexible filament as it appears to be curved. My chrome is lifting in the inside, but not on top. I'm thinking of a guard like insert that covers top and inside edges. I'll add it to the request list as my designer/printer is always looking for excuses to use the device.

 

+1

 

Just had a conversation about the J gate while 3D printing some other parts. Thought is to take a picture of J gate to design top of trim. Once this is correct add a lip that will fit inside gate so it can be pressed in. Unless there is an existing file, this will be need to be designed from scratch. I did not see anything at thingiverse.com but there are a few Jag things in the catalog. Search "Jaguar".

Recommendation is to print in white and chrome paint. There is a acetone vapor smoothing technique that can create a very smooth and glossy plastic finish. See; https://i.gyazo.com/9735ca8d2de13e86...44927b3513.png

 

If you're going to paint the insert you might as well paint the existing part methinks. There's a black surface inside the chrome that the handle is supposed to ride on before it touches the chrome. I think in most cases the chrome just delaminates from the plastic.

I was looking at powder coating processes for plastic and a comment I found was that OEM's tend to hot foil stamp the chrome to the plastic which would be similar to my original comment about die stamping an thin aluminum appliance to fit over the damaged chrome.

Looking at mine I think modelling the part for the 3D printer is going to be a total PITA thanks to the curved top surface. A tissue paper rubbing would get you closer to the top profile than an image for drawing purposes. use the rubbing and compare it to caliper measurements to plan the opening. To do the opening profile, figure out the drop step and chrome radius profile at one point (basically your Z movement) to render the opening in 3d, then give that surface some thickness to create a solid. Now print it. then fit it and figure out where it's loose or tight, redraw, rerender, remodel, reprint. Don't forget to allow for the adhesive and any post processing (sand / polishing). Should be pretty close after the tenth attempt. My seat of OneCNC might be able to do the model but it get's flaky on solids and real flaky with extra curves on the top surface. Easy way would be to find some university that has a 3d probe or laser modeler and let them scan the part into a solid drawing and then offset the 'chrome' surfaces to create a solid for the 3d printer.

I kind of like the idea of the aluminum based duct tape for a real polished finish but it's really, really miserable to work with dang sure will peal at the cut edges. It's also exceptionally sharp when torn and cuts through flesh easily (trust me).

It still keeps coming back to a chrome style paint or powder for an economical repair / refinish.

 

The curvature of the shift platform and bezel is a concern. There are flexible materials that may allow the bend necessary, or this can be accommodated with 3D printing platform techniques. The machine we have can actually print in mid air as bridge between small distances. The design work and prep for printing will be the big part of the job.

Since the original request was for a prototype to be used to have something fabricated, that is where we will start. Although, there are some pretty impressive spray chrome systems that are designed for plastic that could be used in this case. I think the finish work will be easier than we think.

 

How about using chrome wrap material.