I am working on a removable trans tunnel for my 40 Ford truck. I had planned on using self tapping screws run into the 1/2 tube floor frame. Any other suggestions on fasteners? I had planned on using silicone for the seam sealer on the trans tunnel. I made my floor pans with a cut off wheel on a grinder, a 2x4 with a truck on top of it as a sheet metal bender and some 1/4 inch round welded to plate as a bead maker. Floor pans are getting butt welded. My question there is should I just tack every inch or so and use seam sealer or do I need to fill my joints all in with weld? Seems like a lot of time to zap in small increments then keep moving to avoid warpage. If I do weld it all the way then do I not need seem sealer on my butt welds or can I just prime and paint? Please correct me if I am wrong. I am usually wrong.
I'm using 8/32 nuts welded under the floor pan and made a felt "gasket" to under the removable tunnel.
Yoy can use RIVNUTS onder your floor board, Easy to install with no welding required. Use Google for more info..
Are you going to attach the fasteners to those hoops? If so, it may be thick enough to tap so you could use a #8 or #10 fastener. If no, then what 1bigrat said. Riv-nuts are good for access panels that come off every once in a while. Dzus for panels that need to come off quickly and often. Or you could just use Dzus fasteners 'cause they're cool!
Ok...number 1, nice job on the pans! Silicone is absolute garbage if you try to use it for seam sealer. It's not even paintable. You can fully weld in the pans, but personally I would have (or would now if you still have overlaps) drilled or punched holes and spot welded. Use weld thru primer between the panels and then seam seal with automotive grade sealer inside and outside. As for the trans tunnel, any radial seams over the tunnel can be butt welded easily without much worry of warpage...just don't get carried away and weld one long pass up one side and down the other. Do it in inch long bursts and skip around. Butt welds can then be reasonably ground down and painted like the rest of the metal. It doesn't need to be perfect...just take down the beads a bit, clean it well with a cup brush and prime etc. You could use self tapping screws to hold your tunnel to the floor if you want, but self tapping BOLTS will work better, if the riv-nuts etc are a bit out of price range or not so easy to find in your area. Self tapping SCREWS would likely be a pain to remove once they get a bit rusty or fill with crap after a few years of real use. Now...gotta ask...what do you hope to accomplish with having a removable tunnel over a solidly welded in flat bar cage? You can't actually do anything to the transmission...
Ever drop a transmission without pulling the motor and can't get to the top bolts? I have, in fact I cut out pieces of a tunnel and welded them back in to avoid pulling an engine on an OT truck. I also have made my transmission tunnel removable and this was a timely post for myself. Thanks for the various input.
I agree, if you can make it removable, do it. I did on my roadster, helps with installing/working on the brake pedal, speedo cable, shifter as well as the trans bolts. I have also cut holes in the floor of my Studebaker to get at the trans bolts, tight fit to get at it from the underside.
I made mine removable also, after having fun getting to bellhousing and trans bolts on others I've built. I bolted mine in using 1/4" bolts and nuts underneath, then welded the nuts to secure them. Used panhead phillps bolts to hold it down, and used adhesive backed thin foam on the bottom edge to seal it when in place.
Sure I have...pain in the butt. But if you're gonna make it ALL removable then common sense would be to not cage it in below. Removable is a good thing, I agree...but in this case its usefulness in the real world is severely limited by all the flat steel bracing.
Can rivnuts be place with a conventional hand rivet gun? Sent from my LG-E970 using H.A.M.B. mobile app
^^^^ they are made to be installed and removed. Self tappers are made to be used one time and tossed.
I'm doing this right now on my 26 RPU. The trans tunnel and floorboards are going to be removable to access the shifter, trans and parking brake as well as the brake MC. All that stuff would be buried and totally inacessable without removing the body. I'm using 1/4" rivnuts and button head allen bolts to hold the panels in place.
Transmission question... Will your shifter be too far back (under the seat) with that tail shaft? Will you be changing it for the other style that puts the shifter closer to the fire wall?
I appreciate the input. I don't have a Rivnut installer, so I am looking for other options. I may just have to tap and use stainless screws. In response to RuffDawg, the shifter on the T5 should have plenty of clearance from the seat and if needed I will have to put a little of curve in her. I have not gotten there yet but thought about it initially. I thought of swapping tail shafts out but I need the knee room more. I am fat you see. I put a couple of more pics so you can see there is plenty of space between shifter and seat base.
Rivnut tools are relatively cheap. I believe that even Harbor freight sells a hand squeeze one that is capable of doing 1/4" rivnuts. They look just like a typical hand squeeze pop rivet tool. Use steel rather than the soft aluminum rivnuts supplied with the tool however as the threads are more durable. http://www.harborfreight.com/45-piece-threaded-insert-riveter-kit-1210.html There you go, only $16.99
As others have stated, probably the best, cleanest way of having the tunnel removable is to use riv-nuts. I have attached a cple of pics of the way I did it on my 34. The front flange is located underneath the lower firewall section and then I seam sealed the perimiter prior to paint..You can buy a riv-nut tool and the nuts quite cheaply if you have a h.f or similar store near..
If you do decide to use Riv-nuts make sure to use some high quality anti-seize on the threads and don't tighten the bolts super tight. They are a great idea...but my experience leads me to believe that use in thinner sheet metal is a touch and go thing. I've seen quite a few factory installed Riv-nuts spin inside the sheet metal rather than let the bolt unscrew. Believe me...THAT can ruin your day!
I concur. On a related side note, the Aerospace company I work for also makes panel fasteners (which I have tested before) for thin sheet metal and composite applications. They almost all utilize anti-seize and the seating torque values are very low, think snug-tight. Over-tightening will cause failure.
That is why I was amazed that my repop hinge buckets had used rivnuts. I tack welded the back of them just to make sure they wouldn't come loose!
Do any of you all have any experience with the rivet nut guns made like regular pop rivet guns? Just wondering if they get tight enough? Also wondering if that harbor freight model is any count, it is Pittsburgh and it is my experience that the Pittsburgh stuff is pretty decent....... it is still a crapshoot though......
Wow tinhunter, thats a beauty of a floor. Looks like you know what your doing. I ended up going to the hardware store and getting some cage nuts to tack on the bottom side of my floor frame and underside of my flat bar tunnel frame. I will then through bolt. At least that way I can either replace the nuts from the cage if they get gummed up over time or cut the cage out and replace the cage nut. Nothing like over planning and planning on future issues. Thanks for all of the input. I will snap some shots when done.
If you use the ribbed body rivnuts and they are properly installed, they will NOT spin. As well there are rivnuts in different lengths for each specific thickness range of the material you are installing them in. Use the proper ones and you won't have problems. I have a hand one, and also a model with longer handles for larger sized rivnuts up to 3/8" They are both made in England, so are better quality than the HF one. For limited use it should be fine. Mine cost quite a bit more but as usual in tools you usually get what you pay for. Used properly with the right rivnuts for the application the hand squeeze one works fine up to 1/4" Welding them should not be required, although I agree with the use of never seize. And as far as tightening goes, how tight will they really need to be to hold floor pans ? Snug will be good enough. I'm also using them for the base to floor bolts on the steering column I built for my RPU.
Saw plenty of these panel nuts used on cars, and found them new at Fastenal. 1/4" pan head bolts make things easy to take apart and head has a low profile
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