View Full Version : TR2/3/3A trunk/spare tire

07-03-2015, 12:57 PM
Well my trunk/spare tire lid has been moved down to 6 inches. I tried pushing the truck floor up with a potra power, but it just falls down and does that oil can thing. I here chatter about shrinking sheet metal, but never done it. I was going to hold the floor up with some wood and then heat the floor some and see? Or I was going to lift the floor up and try pounding this small area at the apex of the sage back down and see. Need ideas

07-03-2015, 01:29 PM
I've never had much luck at shrinking with a hammer and dolly. Seems like I always either wind up with a crease, or just shoving the high spot around to somewhere else. But I've never been very good at metalwork, so likely just my lack of skill.

However, shrinking with heat worked for me first time. Heat a spot to red hot (using an OA torch), tap it just a few times with the hammer, then clap a wet rag onto it. Move to another spot and do it again. Lather, rinse and repeat. Each time only shrinks a tiny bit, but it does shrink. Lots of videos on YouTube, including a related technique that uses a "shrinking disc" in a grinder to get the hot spot.

07-03-2015, 04:15 PM
Of course, you need to identify where to shrink. Most basically, determine what moved the trunk floor down and where that happened. Then reverse that process using heat and hammer as above. Porta power probably made it worse but it will probably be a good idea to shore it in place (not higher than level) while shrinking.
The trunk floor has several swages that should stiffen it enough to keep it from oil canning under most common loads. My guess is that one or more of the swages is creased and stretched.
Also note that you will need to remove paint from both sides before hearing, particularly important when you look at where the gas tank is.

07-03-2015, 06:05 PM
Yes, I usually use the heat and quench approach. Do a small area at a time....


07-04-2015, 10:54 AM
The vehicle is stripped down with the gas tank out. I was very careful with the Porto- Power and used some blocks of wood and barely lifted it. I have respect for hydraulics. The sunken part it toward the back of the car and looks like the PO set something heavy down probably the head that is missing from the project; it is more of a sage than a crease, but there is a small protrusion up lift of metal left and right of the sage where the floor meets the side frames. I will try and get a picture, but my camera and I are not the best. Does anyone know what the opening should be on pre-6K. I have 6 and the lowest point.

My planes are to use a screw jack this time and lift the floor level and try and pound the left and right pop downs back up in place with some heat. I had not thought of the quenching method and will do that also. It is really not that bad and part of me just wants to leave it. I should just pull the spare out of driver and see if it fits

07-04-2015, 01:53 PM
I don't think the opening is any different pre and post 60 k although I may be corrected. On the later cars the trunk floor, independent from the opening, was raised about 1/4 inch. My opening measures about 7 3/8 and is quite uniform across the opening and into the compartment. Hope we are measuring the same thing. Does the spare tire cover fit?
Your plan seems good. Remember to strike from high to low. When you identify the depression begin by shrinking the edges and work toward the center. If you can't get a hammer into the tire cubby, strike "off dolly" using as much force as possible on the dolly. You can heat either side.

07-04-2015, 03:00 PM
Thanks Tom, I appreciate the help. I am not sure how much the difference is, but I have heard over the years that the post6K are larger because people had a difficult time with the tire, but that is a 1 1/8 and perhaps I better get serious about try to get a spare in the hole. The 6 1/2 is right in center about 10 inches wide and the sage is evenly across the trunk, so I might get lucky and the truck floor will stay up after is shrink it. I think straight and flat it would be about 7 even.

07-04-2015, 04:00 PM
I mean 7/8

07-04-2015, 08:21 PM
Well that shrinking stuff really does works

07-05-2015, 09:32 AM
It accomplishes a couple of things for you...shrinks the steel, which fixes the stretching that caused the problem to begin with... and the rapid cooling with the wet rag hardens it, so it gets rid of the tendency to "oil can".