There are tons of threads about Harpooning, but not as many with specific details for the Ex. I tackled the project today and it wasn't very hard. Took me a couple hours by myself in my driveway. Here are a few thoughts:

- Check out this page for a great overview.
- Keep everything clean! I put paper towels in or around all the hose connections while I worked.
- I jacked the back up by the hitch, way up and up jack stands under the frame rails, then pulled the jack.
- I loosened the hose clamps on the fill tube and vent, but waited until I dropped it a bit to pull them off.
- To lower the tank I used a piece of shelf on the jack, but also had ratchet straps crisscrossed under the tank to catch it if it tipped or dropped too fast. The straps really helped stabilize the tank when I was messing with connections.
- If you reach over the driver frame rail you can feel the sender wires and fuel line to see how much play there is.
- Lower the tank till you can get the sender connector disconnected, I probably dropped it 8" total after checking the wires/fuel lines several times and adjusting the straps to hold it.
- Lower the tank till you can pull the fuel lines. I found the easiest access was kneeling under the Ex, over the axel and front of the tank. They popped right off with the tool.
- I had one size disconnect tool 3/8" if I remember right, but it got both of the fuel lines off.
- Once that is done lower the tank down and pull the tank out.
- The rest of the process is well documented, I used a 3/4"x1"x2' piece of wood and hammer to get the ring off. Wasn't my first choice, but it worked well and the wood softened the blow. To get it on, I used a heat gun to heat up the ring and get it started, then the piece of wood and hammer.

I think that's it. The funny thing for me was the previous owner already had harpooned the tank! I did cut an extra .5" off the vent tube. The fill tube is full length and fills fine, so I left it. I filled a full speed to 45 gallons, I was pretty empty. Overall, a pretty cheap and easy mod.

 

So the main purpose of this mod is to allow for the acceptance of the last 5 gallons of diesel into the 44 gallon tank at a normal rate of flow?

 

i guess thats something id consider if I needed to replace a seal or bad pump or something....but damn that seems like alotta work for 4 gallons of gas =)

 

Wacenturion:
Pretty much. As an added bonus you can usually squeeze a couple extra gallons in also. I put in 45 gallons at the fastest fill rate and had as least a couple in the tank. So, 47ish gallons for the capacity. Not really a deal breaker, but I don't mind the extra capacity.

ycis:
No pump down there, just the pickup and sender so you won't need to worry about it. Some of us like to wrench for fun.(yeah, crazy I know) This was only two hours and didn't cost me a dime, hard to pass up. But, it does allow you to fill easier, that's what I would call the main bonus.

 

haha...its all good.

my todo list is a mile long...I wish I had time to "wrench for fun" :lol

 

If you plan ahead of time you can do the "Hutch Mod" at the same time. Which is what I did on my 7.3 2000 Excursion Limited.

 

Yeah for sure, I get to do it three times a year at most. I have had a downpipe for my Speed6 sitting in the garage for a few years, just need time.