Sub Frame Connectors after Interior is finished

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plumkrazee70

plumkrazee70

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Well... here is my dilhema.

The interior of my dart is finished, and by finished I mean the floor was painted, sound deadening, jute and carpet all laid. It has been done for a few years while I work on the body.

My dad suggested that since I was prepping the undercarriage for paint, I should install some sub frame connectors. I never gave them much thought because this will be a very mild/daily street car. Anyway after some research I bought the US Car Tool ones that form to the floor.

I took out the carpet but cannot remove the sound deading. I am thinking if I just do a 1" or less beads moving around, I should be ok? I just don't want to melt all that deading.

Thoughts?
 
You're going to melt the sound deadening. Even small sections of weld will do that. If it's the butyl backed stuff, it gets soft and tacky at 100*. Not only will it melt, it will catch fire. The paint in stuff like lizard skin might fare a little better, but it's still going to melt and burn.

You're best bet would be going to a tubular frame connector, you can go as big as 3x1.5" without interfering with the floor, all of that welding would take place on the frame rails so the floor should be ok.

The Mopar bolt in connectors work ok if welded in, otherwise the bolts just back out after awhile from the flex. You could make bolt in's work but you'd have to do captured nuts in the frame and reinforcing plates at the connections. Easier to just weld them in.
 
Don't waste your time bolting them in. Buy some 3 X 1.5 tubing and flat plate and no floor mods will be necessary. There are many threads on this if you use the search function.
 
Bummer. I already trimmed the US Car tool ones to fit my floor and primed the inside of them. They are super heavy, so I don't want to try and resell them.

The stuff I have is called Hush Mat, similar to Dyno mat. I just had a thought while typing. What if I just trimmed out the Jute and sound deading in that area? That way nothing will be affected. I think I also have a little left over I could fill in afterwards.
 
I used nylock nuts on a set many years ago - they worked perfectly... like the reinforcing plates idea a lot.
 
383Duster said:
Don't waste your time bolting them in. Buy some 3 X 1.5 tubing and flat plate and no floor mods will be necessary. There are many threads on this if you use the search function.
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I see and saw all those threads after I bought the US Car tool ones. I just can't return what I already have because they have been trimmed to fit my floor. I think I am just going to remove the deadening in that area.
 
plumkrazee70 said:
Bummer. I already trimmed the US Car tool ones to fit my floor and primed the inside of them. They are super heavy, so I don't want to try and resell them.

The stuff I have is called Hush Mat, similar to Dyno mat. I just had a thought while typing. What if I just trimmed out the Jute and sound deading in that area? That way nothing will be affected. I think I also have a little left over I could fill in afterwards.
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oh - you already have them!! Keep a fire extinguisher at hand!
 
I had dynamat extreme on the floor pan of my car when I did my uscartool weld ins and torque boxes. The dynamat fared well enough and I didn't cook my car. I set up a fan inside the car to keep air moving and had no residual smell.
 
Weld the ends of the frame connecter to the frames and then use a bonding material to bind them to the floor. A lot of body shops will bond sheet metal together. Can't you just tack them to the floor and use something with an epoxy based to bond them to the floor?
 
Valiant63 said:
Weld the ends of the frame connecter to the frames and then use a bonding material to bind them to the floor. A lot of body shops will bond sheet metal together. Can't you just tack them to the floor and use something with an epoxy based to bond them to the floor?
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This is what I was originally thinking. Was to weld up the ends and then do some tacks along the floor. I think I will just remove the deadener in those areas to be safe.
 
When you well them in use wet rages in the inside have some one keep keep resoasking them and you as you go
 
Sometimes trying to take short cuts takes longer than doing it right.
 
Sounds like a plan. You can fill the gaps between the welds with seam sealer or something else to give a uniform appearance and seal water out. Then finish coat with whatever is on the underside of the floor.

If it was me, I'd have somebody stand by with a spray bottle of water watching the floor pans from the inside while you weld with instructions to spray if if catches on fire.
 
Well I know one thing, on a hot summer day my 340 makes a lot of heat in the headers and the floor gets well above 140 degrees with the carpet out you can't hold your hand on the sheet metal if you are stuck in traffic and not moving, so if you are careful you could weld it. do short spots and use a blow gun to cool it down before moving on. I would have no problem doing that.
 
Thanks for all the replies everyone.

I am going to just remove the deadener in the area where they connectors meet the floor. I think that will be safest thing.
 
plumkrazee70 said:
Thanks for all the replies everyone.

I am going to just remove the deadener in the area where they connectors meet the floor. I think that will be safest thing.
Click to expand...

I agree. Pull the carpet and jute. With hushmat you should be able to just use a box cutter to cut out a couple strips where the subframe connectors go and peel the hushmat back out, I'd make the strips a few inches wider than the connectors. If it's cold that will work even better, the butyl backed foil type stuff will peel off if you can get some traction on a corner or edge. You may even just be able to lay those strips back in when you're done. I've got RattleTrap sound deadner in my car, you can peel it back and reapply it. If it were on a roof or vertical panel you might need new stuff, but on the floor it shouldn't be an issue.
 
72bluNblu said:
I agree. Pull the carpet and jute. With hushmat you should be able to just use a box cutter to cut out a couple strips where the subframe connectors go and peel the hushmat back out, I'd make the strips a few inches wider than the connectors. If it's cold that will work even better, the butyl backed foil type stuff will peel off if you can get some traction on a corner or edge. You may even just be able to lay those strips back in when you're done. I've got RattleTrap sound deadner in my car, you can peel it back and reapply it. If it were on a roof or vertical panel you might need new stuff, but on the floor it shouldn't be an issue.
Click to expand...

Thanks, Man.
 
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