Gas Tank Straps

[dawgs 73]

Does anyone know if the gas tank straps had rubber or some other kind of insulator between them and the tank? Oh, yeah, '73 Cuda..... Thanks in advance

[Street_Challenged73]

I'm pretty sure they just fit tight up against the tank without any insulation between the two.  Granted, I'm going off just what my car had, but it seemed as though nothing was ever removed in the back prior to my acquisition of the car.   I could see if the straps didn't fit tight to the tank there could be some problems with vibration causing wear, but as tight as mine were to the tank I wouldn't really give it a second thought.

As I'm sure you know, there is a piece of insulation between the tank and the trunk pan.

[Bullitt-]

My '73 Challey had nothing between the strap & tank..but there is a pad between the tank & trunk.

[Tropicalcats]

My 70 had nothing between the straps and tank. Just the pad between the trunk and tank

[Grec]

Yep. Just metal to metal with the pad between the tank and frame.

[duodec]

But beware if a mechanic or previous owner ever pulled the tank... they might have lost the pad between the tank and trunk, and substituted a couple of shop rags.  Water absorbent shop rags.  At least I didn't live in a salt-spreader area, but the tank was pretty raggedy on top.

[Jacksboys]

My 70 had nothing between the straps and tank. Just the pad between the trunk and tank

Same thing on my 71 Challenger.  When I put the new tank back in, I just used a piece of tar paper between the tank and body.  Then I just made sure the straps were on tight.

[IMNCARN82]

This car had a new tank put in recently. It has some sort of liquid gasket material inbetween the straps and tank.

[Super Blue 72]

My '73 Challey had nothing between the strap & tank..but there is a pad between the tank & trunk.

My '72 also like this. 

Although there is a little vibration from underneath the tank from the tank straps.  Becareful what you use as duodec was hitting on certain materials that can absorb moisture and thus prematurely rust the tank in spots.  Foam is tempting to use but will retain moisture.  Maybe that's why IMNCARN82 had liquid gasket there (I assume silicone?) to stop any vibration.

[Tropicalcats]

Does anybody make a pad for between the tank and trunk that will not absorb moisture? Those original tar ones did not do the trick and is why alot of trunks rusted out.

[dawgs 73]

I have to ask................ is the deal with the tar paper absorbing water and causing rust what the real problem is, or is it that, since the tar paper is laying down on top of the gas tank, any moisture that ends up there can't evaporate and just sits there on top, causing the rust. The moisture doesn't have to be from water being splashed up there, it could just be from real high humidity (Missouri in July and August comes to mind here.) What does the pad / tar paper even do there anyway?
It seems to me that you could probably leave the tar paper off and may be better off. I'm not saying that I'm going to do that, but it just seems logical to me........ Opinions anyone else?

[Bullitt-]

In my case the minor surface rust under the trunk where the tank pad is was no worse than anywhere else.  If you were putting your car into daily service this might be an issue but if your like most of us I think it's not worth much worry.  The pad is probably there for sound deadening as much as anything. While I could re-use the original or replace with an original type piece I am contemplating using closed cell foam(that does not absorb moisture).

[LAA66]

 Just removed my tank and no rust to be found.  I had installed a piece of insulation many years ago when I had to patch the bottom side. I don't drive in the rain as a rule however, after reading this post the insulating material would seem to hold water. Contemplating using a rubber shower floor mat between the two when installing the new tank.

[Bullitt-]

May sound like I'm talking out of both sides of my mouth but the original type material bay be best as if it does get wet eventually it would dry out, where as rubber or foam that does not absorb moisture may also tend to trap any moisture that gets between the surfaces, think condensation....Proof be in the pudding so to speak.

[HP2]

..could alway try an asphalt shingle. This pad was a sound deadner as well as a tolerance take up device. You could leave it out without any ill effects.

The mounting bolt for these can also be a problem. These are available new from mopar, pn 4002006,tank-gas strap j-bolt all models,$24.20, or so.