What is the secret sauce to the installation of the "J" hook on 70 Challenger?

I had removed heater to resolve noisy fan,,,found that was not shoved onto motor shaft as far as it should have been.

All back together except having problem attaching hook. I have vent open a and can get my hand on it ok.

Also the hole in plastic housing thru which the screw goes is broken out,,so I will be using an oversized plastic washer to hold screw in place,,,May epoxy in place later.

Any advice on how to eliminate harmonic vibration rattle from entire heater appreciated. If I push with my foot or hand against heater,,,,the rattle pretty much goes away

Here is a URL to a posting that shows illustration of the entire heater assembly and said hook.

https://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=6068326&page=0&vc=1

Image of hook attachment

I just installed my box. I had to bend the flange of my hook where the bolt attaches so that it would reach further towards the metal cowl anchor point. Before I did that, when I went to tighten it the hook would pull away from the anchor point. Bend it so that it can catch and remain on its anchor point.

Also, it is imperative to have a strong base for the anchor screw to rest on. This area is notorious for its weakness and damages easily. E-body non A/C heater boxes have just three small nuts around the heater motor to secure it to the firewall. The only other anchor is the hook which holds the box secure within the car. The hook holds the entire assembly securely and also seals the vent box to the cowl plenum.

I made a metal "Z" if you will and riveted to the box so that I would not have to worry about pulling through bolt when installing the box anchor hook.

Once I got my anchor to pick up the cowl, the vent box fits tightly and securely. I suspect your issue with vibration was due to the fact that your anchor hook was never properly situated.

Here is a pic of my vent box. If you expand the r/h side you can see the reinforcement I put in at the hook hole. You will more than likely have to do something similar in order to get this area of your box to work correctly. The damage you say exists around your hook anchor hole on your vent box may keep you from intalling it properly.

Quote:

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I had to bend the flange of my hook where the bolt attaches so that it would reach further towards the metal cowl anchor point. Before I did that, when I went to tighten it the hook would pull away from the anchor point. Bend it so that it can catch and remain on its anchor point.

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Exactly what I had to do on mine. I tried installing it a few times and failed. After I bent the hook slightly, it went right in.

I guess I got lucky, no bending necessary. If I remember right I just started the bolt and lifted everyhting into place, reached through the vent and hooked it in place, tightened the bolt and all is well.

Another part to run down, that I didn't know I was missing!

I am still struggling with this. Likely because someone in the past had over tightened the bolt causing a dime sized hole instead of the normal 1/4th normal hole. I am trying to use a larger washer to cover the hole and to provide the tension required.

Am I correct in assuming that the "hook" should be pointed straight back toward the glove box?

I may have to remove heater to properly repair the broken out hole. However is likely important that once repaired, I must be exact in where to drill new 1/4 inch hole,,,this will be difficult as I do not know exact placement now.

I've also tried using a longer bolt/actually a stud. This so I could set the hook and then use a nickel sized washer and then a nut on the stud"bubba fix". But this seems to throw the alignment off causing the hook to disengage.

Perhaps some can toss out some other ideas that I might try.

Maybe a battery hold down bolt it you can find one threaded to the bottom. Frankly I would find a replacement box and fix it right.

Fixed for now.

I took a 1/4 inch nut and screw forced it on the tip of the hook. This served to much better holding it in place so that it would not pop off while do the next steps. I did not wish to bend the hook and do believe that this even holds more securely

Then I took a 2 inch 10-24 bolt(same thread as the base of the hook) and shortened it by cutting the head off, leaving it about 1/2 inch longer than original bolt that screws into the hook.

I then screwed this now stud into the hook threads, holding it in place with a couple 10-24 nuts. I then placed this new assembly into the heater, and then holding it in place after getting it "hooked", I took 3/4 inch(larger than the dime sized hole previously noted where the plastic was broken out) square piece of scrap thin steel(almost like spring steel) drilled a hole in it, place it over the threads of the previously noted 10-24 stud, placed a nut on it,,actually 2 for insurance and cinched it up.

Wish I had been sitting on the shoulder of whatever engineer thought that he had a flash of genius some 40 plus years ago when designing this miscarriage. Likely thousands have cursed it over the years. What should be at most a 1 hour r&r on the heater can turn into several hours. I have no idea what a mechanic with a larger pair of mitts does when he finds that he cannot squeeze them into the vent to get this thing in place. As for me, I had to place duct tape in the back of my left hand to prevent cutting it up when squeezing it into this vent. A real pain when removing it,,,now I know what bikini waxing must feel like.

One day I will fix this all correctly, until then I won't let Galen G. look under my dash.

Thanks to all of you who chimed in with support.

By the way before I had read the posting tip on a battery hold down, I had purchased a 1 foot length of 1/4 inch threaded stock with exactly your thought in mind.

Had issues installing as well on my Cuda, I had a friend reach in through the removed screen on the cowl and hold the bar in position, while I tightened the bolt.

You bring back such fond memories.
Thanks.