Full Size Jeep Network

Got a big @$$ dent in the bottom of the gas tank. Want to replace it with a larger custom tank. BJ’s OffRoad makes a 27 gallon tank that looks legit. Is $1,300ish a fair price. If not who/what would you recommend instead?

Does it leak?

It does leak but not from where the dent is. I haven’t looked closely but I think it’s from the hose. The gas gauge inside dash is all jacked and is not accurate. Prolly the sender unit. But my ultimate goal is to hold more fuel. Any recommendations? Gotta be able to “bug out” and go far fast.

Replied in your other thread. If you want capacity, a second tank behind the axle will provide a lot more capacity than the $1300 option. Jeep lists the factory capacity at 22 gallons. Adding a 42 gallon Suburban tank mentioned here - viewtopic.php?p=163357#p163357

Looking quickly at this, the BJ's tank goes behind the rear axle. Any tank placed in this area will prevent putting the spare tire in that location (the factory location). You could go with no spare tire, or put the spare in the interior, or on the roof. A swing-away tire carrier for behind the tailgate may exist from the aftermarket, or you could make or have one made. For the factory gas tank location, you can choose either the factory tank (22 gal) or the MTS plastic replacement (21 gal).

You can run the original tank, a tank behind the axle (like the BJ's tank), or both. If you have both, you'll need to switch between tanks, but that will give you the most capacity. Likely the maximum is 22 gal in the factory tank plus 42 gal with the Suburban tank, for 64 gal capacity. More than that, you'll need to carry cans.

There are several tanks from other vehicles that can fit in the area behind the axle. Here you'd need to buy the tank and adapt it to your Jeep. These are under $200, but require more adapting from you. The largest of these appears to be the '95 Suburban tank for ca $120 at RockAuto, plus any stuff to install it. Note the Suburban tank will hang down a lot, affecting off-road capability if you care about that.

If you want a custom aftermarket tank for behind the axle, there's the BJ's 26 gal tank (aluminum) at $1300, or a 29 gal tank from Aero (likely steel) for $485.

Here's the Aero tank:
https://aerotanks.com/product/1974-1991 ... iary-tank/

Year range starts for '74, but I don't know why it would not work for a '73. Something to investigate. BJs says their tank must be modified to work with a '73. Likely the same issue with the Aero tank - suggest you call and ask.

Note my J20 has a steel aux tank of about 20 gal in the spare position. It came to me this way. It's constructed of steel like the Aero tank, and I suspect it's a generic aux tank that was adapted to this space.

Looks like my 74 tank... when I pulled it out some years ago
and after...
somebody had put a suburban or a large tank that fit in the OE location, but lost some clearance, around 2".

I would suspect that the change from 73 to 74 would be either hose sizes or mounting attachments... which in these years 1 middle strap and some frame anchors

Otherwise the biggest drawback is the increased weight on the frame, aka during one of these transcontinental races, either the Beijing or Peking to Paris or the London to Sydney rallye some years ago where the "Grand" Cherokee had to abandon because of frame or structure failure due to the installation of larger gas tanks

Comparing the illustration and some listings from the '62-73 parts book and the '74-80 book, '73 and '74 factory tanks are the same except for the vapor plumbing. In terms of overall shape, filler diameter and shape, and brackets/support, they are the same. The '73 tanks have a vapor tap at each corner, while the '74 tank moves some of the vapor plumbing to the interior of the tank. This reduces the vapor taps from 3 to 2 in '74. For other Jeep applications, this same plumbing change obtains, and the later tanks work fine for the earlier applications. You simply make fewer connections and plug the extras.

NB this is enough difference to prevent aftermarket sellers from listing the '74 tank as suitable for a '73 or earlier. They don't gather the detail of information we would have from first hand observation, or just looking at the parts books. Perhaps there is some other important difference that I have overlooked, but I don't think so.

This should not affect the suitability of the aux tank, but maybe it inserts enough doubt in the seller's minds to affect the listing. I'd call BJs and ask.

As an aside, I remember that at least one '72 era CJ replacement tank came to the parts department with the corner fittings broken off. Apparently soldering the tube to a hole in the tank was not sturdy enough for rough handling. Maybe this was more common than my anecdotal experience in '74-5, but it could be a reason they reduced the number of external taps.

If it's leaking
Don't buy and inspections is better than regrets