Sub tank install questions (1 Viewer)

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Romer

fatherofdaughterofromer
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I am looking at Georges excellent write-up on the Sub Tank install and have a few questions for those that have done this:

http://george4wd.taskled.com/auxtank.html

1) What size drill bit to drill the whole for the other two Rivnuts?

2) It would seem you would want to do the first two Rivnets, install the brackets and test fit the tank and mark where the other Rivnets should be drilled/installed. Is that correct.

3) What is the pinnout of the existing sub tank connector that mates with the subtank and what wires do they match in the harness near the existing fuel tank?

Edit - found info on colors from another post. I can figure it out from here

On my sender I have three wires

White/black = ground

yellow/red = fuel guage ie fuel level full, 3/4, 1/2, 1/4 etc

white/green = fuel empty


4) George cut removed and replaced the existing filler hose, where do you get the replacement filler hose from the tank to the dual neck with the vent tube? Couldn't you reuse the removed tube, but cut down and fitted with a coupler on the inside. By coupler, I mean a smaller short metal tube to insert at one end of the cut tuube and at the other end with a hose to the Dual neck.

5) The bracket in the pic just below and to the right of the tank came with my setup. Where does it go?

attachment.php
 
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Here is a good item I found in an earlier thread that I will need to do

Dan

How do I test the sub tank empty wire on the sender to verify that it is working?

You will need to pull the sender out and lift up the the empty switch. When the curcuit is open (raised) you will not have continuity between the WB ground wire and the YG tank empty wire.
 
Ken,
Yes, installing the front two and having the straps in place allows you to test fit the tank and determine where the rear ones should be drilled. However, it ends up being pretty much dead center on those two channels. The size of rivnut/nutsert you use would determine the drill size. Typically 3/8" or 5/16" bolts and matching rivnuts are used so depending on which you choose it should indicate the drill size.

For removing the original fill tube I would suggest doing what Dan and George and I did, remove it in a manner where your cut preserves the "elbow" bend as much as possible and also keep as much length in the horizontal straight section as possible. The OEM replacement one isn't really necessary as it is just a cleaner version of what you will have once you cut your. You could have someone roll the end of it giving you a lip too and it'll be even more close to the OEM one.

Depending on which dual neck you get you may just need straight hose and use the "elbow" section like Dan did. Dan was able to source the other bent hose as well I thought.

I was going to ask about that bracket the first time you posted the pic in the SeaMail thread! What is it?

edit: see it that bracket mounts in the four captured nuts in the last frame cross member (facing back) and the hoop wraps around the front of the aux tank...for safety, protection, ???
 
Thanks Mike, Thought I could re-use the tube.

Here is something interesting I found on installing Rivnuts. I have never done them before, and Dan described to me the process. It's for a different application so I removed the bolt specifics. Just want to get across the concept:

To prepare the first rivnut for installation, grease the threads of a bolt and place one washer on it. Next, thread it through the centered hole in the rivnut tool and into a plain rivnut. Insert the rivnut into one of the rear outer subframe holes until its head is completely flush with the bottom of the subframe. Using a socket and ratchet, start tightening the bolt while counter holding with the aluminum rivnut tool. Maintain a steady upward pressure on the rivnut as you are tightening the bolt to ensure that it is butted up against the subframe. As you are turning the bolt, the center section of the rivnut will slowly mushroom out/expand to lock the rivnut into the subframe hole (The mushrooming action takes place inside the subframe and cannot be seen.). Once the rivnut is tight enough to completely stop turning in the subframe hole, finish tightening it with a torque wrench to 35 lb. /ft to fully lock the rivnut in place. Once this torque has been achieved, reverse the ratchet and remove the bolt and tool from the rivnut.​

Now an item of note here are that the tool will not fit here and several alternatives were discussed in this thread

https://forum.ih8mud.com/showthread.php?t=7578

I thought I would post the above as a key step in the process.

With the above description - the drill bit size becomes pretty obvious. Take the rivnut and see how big the bit needs to be to barley clear a hole.
 
Ken,

I installed mine similar to CM's.

I used a dial caliper to determine the drill bit size. It is critical to get the drill size as close as possible to the OD of the nutzert/rivnut.

To install the nutzerts / rivnuts....I used bolt, washer, tool, Star washer, & nutzert / rivnut. The Star washer grips the surface of the nutzerts/rivnuts & the tool, allowing for an easy installation. I used a ratcheting wrench & the tool to install.

Here is a picture of the tool I made to install the Rivnuts / Nutzerts.
Nutsert Installation Tool v1.jpg
 
Ken, sounds like you are up to speed - just waiting for that filler neck, eh? ;)

One note I would add since you are just starting this. I had all of my rivnuts fail on this last trip to Death Valley with the NorCal group. They lasted four years since it was the first DV trip that spurred me to install my sub tank. What was truly interesting is that the rear two pulled completely out, tearing the sheet metal of those rear channels. The rivnunts/nutserts were ones I sourced locally and can't remember which brand they were but they were steel and installed just as advertised. Plus, as you know the rear ones are completely accessible and you have no issues whatsoever using the real/right tool. The tank was full and there were several occassions the entire truck was airborn and I guess time just took its toll on them. The rivnuts that pulled through probably had 1/8" of mushrooming so I imagine that translates to some substantial holding power.

The rear channels are just single walled, relatively thin gauge sheet metal where the front ones are at a junction and are essentially double thickness.

At any rate, Inverness on this list had some nifty pre-manufactured plates of 0.25" thick material roughly 1" x 3" and in the center was a thicker boss 0.5" thick pre-threaded to 3/8", and on either side of that two rossette weld holes. We ended up cleaning up all the surrounding metal and was able to weld these completely around the perimeter and the two rossette holes. Some rattle can primer and paint and I can definitely say that tank is now solidly in there.

It's a hell of a lot more work but if you think there is going to be a lot of trail use that would stress those, I wouldn't rely on the rivnuts/nutserts for long term abuse.
 
Ken,

Found a blurry picture of the OEM sending unit wiring.

I still need to connect George's Relay & the OEM switch!
Do you have the wiring schematic you used?
What type of connectors did you use to connect to the switch terminals?
DSC02891.JPG
 
Mike,

I was almost going to mention about your tank flop!

Oh, and another solution - stop jumpimng that turbo'd monster :)

One note I would add since you are just starting this. I had all of my rivnuts fail on this last trip to Death Valley with the NorCal group.
 
Ken,

Found a blurry picture of the OEM sending unit wiring.

I still need to connect George's Relay & the OEM switch!
Do you have the wiring schematic you used?
What type of connectors did you use to connect to the switch terminals?


I used Boston Manglers Diagram along with Georges of the switch. I then brought the 3 wires to a 9 pin molex connector at the DS kickpanel where I intend to connect the +5V and Ground.

On the other side of the Molex connector I wall have a harness run under the door trim to the plate held down by two plastic srews which looks like a step in the rear door. Christo tells me there is a grommet there I can run down to the fuel tank. I then will add the three pin connector Cdan sent me and pull wires out of the existing harness that go to the subtank connector that is existing. Dan sold me splices and the mating 3 pin connector to make this connection.
 
Ken,

Not much to add, but I am also getting the wires and pins from cDan. Dan also is sending my several new vent tubes and filler hoses and said I will have to cut some down but they will be the right size.



:beer:
 
Ken, check on the bracket (post#3)...the suspense is killing me!
 
Ken, check on the bracket (post#3)...the suspense is killing me!

I was hoping you could tell me??


Edit: pictures added here are so I can link them in the FAQ item. They are subtank pics but not necessaraily this topic
Sub Tank.jpg
Sub Tank 010.jpg
Sub Tank 013.jpg
 
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edit: see it that bracket mounts in the four captured nuts in the last frame cross member (facing back) and the hoop wraps around the front of the aux tank...for safety, protection, ???


pull out the bifocals dude
 
Mike - looked around where you said and it's not obvious to me where that extra bracket goes.

Looking up under mt ruck last night to plan it out, my trailer connector looks like it might be in the way. If someone has time to measure the back lip in the tank to the left open area (where the connectors are) I would appreciate. Otherwise, I will test fit it and see how much room is there.

install2.jpg
 
Ken, sounds like you are up to speed - just waiting for that filler neck, eh? ;)

One note I would add since you are just starting this. I had all of my rivnuts fail on this last trip to Death Valley with the NorCal group. They lasted four years since it was the first DV trip that spurred me to install my sub tank. What was truly interesting is that the rear two pulled completely out, tearing the sheet metal of those rear channels. The rivnunts/nutserts were ones I sourced locally and can't remember which brand they were but they were steel and installed just as advertised. Plus, as you know the rear ones are completely accessible and you have no issues whatsoever using the real/right tool. The tank was full and there were several occassions the entire truck was airborn and I guess time just took its toll on them. The rivnuts that pulled through probably had 1/8" of mushrooming so I imagine that translates to some substantial holding power.

The rear channels are just single walled, relatively thin gauge sheet metal where the front ones are at a junction and are essentially double thickness.

At any rate, Inverness on this list had some nifty pre-manufactured plates of 0.25" thick material roughly 1" x 3" and in the center was a thicker boss 0.5" thick pre-threaded to 3/8", and on either side of that two rossette weld holes. We ended up cleaning up all the surrounding metal and was able to weld these completely around the perimeter and the two rossette holes. Some rattle can primer and paint and I can definitely say that tank is now solidly in there.

It's a hell of a lot more work but if you think there is going to be a lot of trail use that would stress those, I wouldn't rely on the rivnuts/nutserts for long term abuse.
What happened when your tank fell? Did all four rivnuts come out?
I was not sure how well those would hold.
 
Ken,
I'll go measure that now since we are working on the trucks now.

This cross-member. On the vertical surface facing towards the rear of the truck, there are two pairs of captured nuts in it. the hoop looks like it might wrap down and under the leading part of the aux tank like a protective hoop or ???

edit: to possibly act as a forward brace for the spare tire like the rear brace we all have on our rear cross member?
aux tank.jpg
hoop.jpg
 
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Well I just got back from Colombia, and a friend of mine has a 94 80 with the factory subtank. Read your thread while I was there and took some pics that may help you with your questions ... Hope this helps.

245882871.jpg


245882916.jpg


245882925.jpg


245882936.jpg


245882942.jpg


245882951.jpg
 
Thanks,
That answers the question on the bracket
 
Anytime.. I am wanting to do this mod to my rig.. If only I could find a killer deal like you did... Maybe when you get done you can post a complete list of everything you need to make this thing work...
 
the sub tanks have been coming up on and off since the forum moved to Mud. Can the sub tank threads be added to the Sticky's area like the bumpers/dual batteries/ etc.
Congrats on your tank, I love mine.
Are you still trying to source a dual neck? I have been keeping my eye out on ebay and such and haven't seen one yet, How about the poster who got the box from Oz, is that an option for you.
Good luck
Steven
Nevermind I found your Seamail thread, I am so behind!
 
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