Improved method of dropping gas tank

Started by Rickf1985, September 28, 2016, 06:07 PM

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Rickf1985

I want to give a shout out to CapnDirk for this brilliant idea.

He and I were BS,ing over e-mail and the subject of dropping the gas tank came up and he said "you know what would work good?".
Here is what came of that discussion.

On mine and his 80 gallon tanks they are held by the normal straps across the tanks plus on each end there is a flange that is bolted to a cross member. Take out the corner bolts and replace them with long pieces of 3/8" threaded rod and large enough washers to cover the holes in the mount. Run the nuts and washers up from the bottom to the flange and then remove the rest of the bolts and straps. The tank is now hanging from the rods which you can either turn the nuts to lower or raise the tank a hair with a jack and run the nuts down some by hand. Since the tank will be supported at all four corners it will not have to be empty. The rod and nut system will allow it to be angled as necessary. And using the 3/8 rod will leave plenty of room in the holes to be able to push the tank side to side or front to back to clear obstacles. You also do not have to worry about have to try and balance it on a jack as any gas moves around inside, I can personally attest that only a small amount of gas can make a large tank very hard to handle.

I believe this would work on tanks that only have straps also as long as you are able to remove the straps and have access to the holes. Hold the tank with a jack, remove straps and replace with threaded rod and fabricate a couple bars to go across under the tank. 

Let me know what you all think. 

tmsnyder

Seems like a good idea, especially if dropping the tank by yourself with no extra hands around.

Hobbes


87Itasca

Definitely will go this route when I drop my tank. Hopefully no time soon, but you never know.  :D

CapnDirk

Thanks Rick  :)


Rick improved on it by pointing out that once the rods were in place, you could take the weight off with the jack and loosen the nuts a couple inches at a time end for end or side to side.  Also when you are down to the jack being bottomed out, just remove it and use a ratcheting wrench or whatever to completely drop it on the ground.  Way safer, and a buddy isn't needed, but faster if one guy on jack, and one on backing off the nuts.  You don't need rod length all the way to the ground, the flange on our tanks is 3/4 the way to the top of the tank so flange to ground minus 4" would probable be fine.  OR measure bottom of tank to ground and add a couple inches to get to the top of the chassis bracket plus nut and washer


What bugged me about my recent tank drop is that on the P30 the metal part of the filler (part of the tank) that joins the rubber fill hose is INSIDE the frame rail.  It came out, but we literally sheered the hose off the tank putting it back in, and distorted the steel mouth.


As Rick pointed out, 10, 30, whatever gallons of gas will have a tank doing whatever it wants to  ;)


And..... It's "cheep"!  Key word on older motorhomes and their older owners!  :D
"Anything given sufficient propulsion will fly!  Rule one!  Maintain propulsion"

"I say we nuke the site from orbit.  It's the only way to be sure"

Rickf1985

Actually the mention of the 3/8 threaded rod is more of a suggestion than a requirement. That size should fit through the hole and give play to move the tank. Threaded rod size is basically to be determined by the circumstances at hand on each job.
An 80 gallon tank filled full will weight roughly 550 lb.s so that comes out to about 112 lbs. per rod. Even 1/4" rod would work but I really would not go below 3/8 due to the fact that anything smaller could be subject to bending and fatiguing and breaking from that. I doubt anyone is going to drop a full tank unless it is impossible to get the gas out.

djlgnd

gonna do this with my winni when i replace the fuel pump, love this idea

ErikTande

This is a great idea, so 4 lengths of 3/8 in rod, right?   Does anyone have a picture of where you're putting the rods/washers/bolts?  I assume you're leaving the 2 end straps on the tank and running the bolts through there, then removing the center strap completely, right?  Or keep all 3 straps and use rod on all 6 holes?   


Do I have the concept right?  Still using the straps to support the tank?  And the straps have bolts on each side?

Rickf1985

On mine there are flanges welded to the ends of the tank and I had the rods through that but if your tank is held by straps then yes, take the bolts out of the straps and replace with the threaded rod. I thought I put up a thread on the removal of my tank, I may not have since I only dropped it down far enough to reach the lines and replace them. I will see if I have any pictures. I am pretty sure most of the big tanks are going to have flanges welded to them but if they have straps they should be bolted at both ends. If you have straps that are only bolted at one end this method will still work to lower the one side of the tank to the ground which is usually enough to get to the lines and such. That is something you would normally see on smaller tanks like 25-30 gallon max.

Shawn62

ErikTande,
     On my 1987 Southwind the tank straps were bolted on the right side.  The left side ends of the straps were welded to a piece of angle welded to the frame. I used a motorcycle jack to lower the tank.  I Put blocking between the straps so the straps  could flex and slide to allow the tank to come down. I will have to look and see if there are holes drilled in the frame flange to use the threaded rod method. 

ErikTande

Quote from: Shawn62 on July 30, 2019, 08:49 PM
ErikTande,
     On my 1987 Southwind the tank straps were bolted on the right side.  The left side ends of the straps were welded to a piece of angle welded to the frame. I used a motorcycle jack to lower the tank.  I Put blocking between the straps so the straps  could flex and slide to allow the tank to come down. I will have to look and see if there are holes drilled in the frame flange to use the threaded rod method.
That's what I was thinking I remembered seeing last time I looked, bolted on one side and welded on the other, I'm not positive though.   I have a trans jack so I might use that.  When you unbolted the straps they had to bend to let the tank down, right?   

Thanks!

Rickf1985

I have never seen straps that were welded on one end but I will not say that is not possible on a motorhome after seeing the welds on the rear frame!! Welding tank straps to the frame is just asking for a failure! Usually they are bolted at one end and then the other end may be welded to a bracket that is bolted to the frame but most often they are slotted in a notch in a bracket so they can pivot down. Plus, all frames flex so bolting and or notching allows some movement of the straps so that do not break and drop a large gas filled firebomb going down the road.

Shawn62

    Rick,
      I agree.  I donââ,¬â,,¢t know if this is original or some PO had it done.  The welds are very suspect to say the least.  I was curious if ErikTande has the same deal. I never really looked at the left side strap connection until this thread.  I thought it was a hinged bracket assembly. I will change the system when I put it back together after I do the frame extension re-weld.

Shawn62

EricTande,


        Yes the straps flexed/bent as I lowered the tank down.

c farmer

Good info.  I keep my tank full so I am wondering how to drop it when somethng happens with a full tank.

sharon051266

Awesome advice seeing as this spring I have to drop my tank and I'm working on this by myself.
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