'70 'Cuda J55 Undercoat with Hood Pad Details

[70_440-6Cuda]

This may have been addressed already, but I was unable to find the definitive answer I am looking for.  I have the J55 code for Undercoat with Hood Pad and am trying to understand what exactly that means, and what were the other options?  Also, I am very early planning and want to understand what the car should look like underneath - specifically what areas should be painted and what areas should be undercoated?  Sorry if this has been answered already - thx

The car currently has undercoating almost everywhere so just wondering if that was added later at some point or that is factory

[anlauto]

With J55 you should have undercoat everywhere. You can see the thick coats of it on your floor pan.

[headejm]

I have a J55 coded 1970 Challenger and here are some photos of my car during restoration.

Key points:
1. Check out restorick.com for the most authentic undercoating product. That is what I used. I left my old undercoating on and still used one gallon. Could've used one more quart.
2. If your current undercoating looks solid, don't try to remove it. Pick off the pieces that want to flake off and leave the rest. I left my original undercoating on, misted it with lacquer thinner, and sprayed the new right over the top 0f the old.
3. Follow and duplicate the undercoating patterns that are currently on your car. The factory didn't have a formal process for applying the undercoating. No two cars are alike. The worker held up cardboard pieces and sprayed around it.
4. The fuel lines, brake lines, fuel tank, and muffler shields were all installed prior to undercoating. Follow your current car's patterns.
5. Search "Undercoating" on our main page and you'll find lots of discussions.
6. Completely spray the quarter panel wheel wells.
7. Completely spray the inside of the fenders while masking a couple of spots like where the side markers go. Once again, follow the current patterns that are there.

8. No one is reproducing a nice underhood pad. My 50 year old pad was shot and I had to settle for what is available. Also, the new pads are thicker and the factory steel clips didn't work. Ended up using modern plastic molding pins with a 1" shank. It's just okay looking.

Check out my photos and let me know if you have any additional questions.

[anlauto]

  The above is all great advice, Specially if you're going for a judged event or correct OE look, however, it's been my experience that factory undercoating trapped a lot of moisture over the years and usually hiding rust under it. I would personally hate to do a ground up restoration and NOT remove all of it to be on the safe side.

[70_440-6Cuda]

That is what I was looking for - thought that would be the case but wanted to make sure I understood the code correctly.  I have ideas of making my own tip over jig and doing this myself so we will see how it goes. Challenger looks awesome by the way...

[69BFan]

REM makes a decent quality molded hood pad for the various Mopars with the sound deadening option.  They are not the loose fiberglass style that is simply die cut to match the outer profile for the hood pad.  The reproduction metal hood pad clips are a real pain and have the tendency to pop out once installed.  If you decide to replace a molded hood pad, try to source good used original clips as they work better than any of the reproduction clips.

[headejm]

@69BFan Maybe REM improved the design in the past 4 years but I have a REM pad on my 1970 RT and it's not very good. Too thick, too stiff, and too brittle. It's also the best one I could find at the time. Had to repair a few spots where the clips damaged it. I wish there was a good pad available but I haven't found one yet.

[anlauto]

I bought the hard molded pad from Richard at Carlisle and got it installed on my 71 Cuda using the reproduction clips. It was a challenge to get it installed, but so far so good, no clips have popped out and gone missing 

[69BFan]

@headejm, I agree that the REM pads are far from being absolute accurate to the OEM pads, but they are far better than any of the die cut fiberglass pads that are available.  They at least have the profile and molded areas to duplicate the assembly line pieces.  It seems that the REM pads are a bit thinner now, but my main concern is that the manner in which they are molded makes them brittle and easily broken if not handled properly.  The poor fitting metal pins are also adds to the problem.  Some people use the late 72 style plastic clips as they are much easier to work with and less likely to damage the pad.

I have only seen one NOS molded hood pad come up for sale and that was almost 30 years ago.  The original pads were actually quite thick, but the material was much softer and thus it was easier to compress the area to install the metal push pins.  The newer material is more brittle and if not careful, you will bust out the area in which the contact is applied.

[anlauto]

I'm no metallurgist, but I think the new reproduction clips are NOT made of "spring steel" and that's where the problem comes from in my opinion

[autoxcuda]

The above is all great advice, Specially if you're going for a judged event or correct OE look, however, it's been my experience that factory undercoating trapped a lot of moisture over the years and usually hiding rust under it. I would personally hate to do a ground up restoration and NOT remove all of it to be on the safe side.

In 30 years of California mopars. If this is an original California solid not rusted car... just brush off the loose undercoating, power wash it, scrub it, and apply fresh good undercoating on top.

If you really want it nice, fill in the missing chunks with seam sealer and dab with steal brush to get right texture. Then just enough undercoat to give it a fresh black look.

If you are painting the car, do the fresh black undercoat after paint. You'll have to clean it some to get the paint overspray off. 

[anlauto]

That must be nice...for 35 years I've been doing Canadian cars....different story altogether..

[autoxcuda]

That must be nice...for 35 years I've been doing Canadian cars....different story altogether..

This is the undercoat on my California 68 Barracuda 340. That shiny Burgundy paint where the undercoat is knocked off is my original paint RR1 Burgundy. I can see fresh grey primary if I chip it off in certain places.

That's the original tail pipe with weep hole too!