Fuel cell & rear shock mount Q&A

[Davs]

Hey kids, I need some opinions and any legals about fitting a fuel cell under the body/above the rear tailshaft?
I think i would have to mount the fuel cell cradle through the floor at one end and to the rear crossmember on the other end.
The fuel cell is 177mm (7") tall, 760mm (30") wide and 430mm (17") deep. It would fit nicely between the chassis rails and crossmember and the height is no worries either.
My problem is that I would have to relocate the rear shock mounts to under the crossmember and the exhaust pipe would run very close to the fuel cell.
Anyone have any alternative suggestions or issues I might run into?

 

[chicago]

I just did this in mine, essentially. I actually had to build my own tank though. Im going to try and divert ANY attention by the DMV into investigating what type of tank it is.
I built a x member for my wrap bar, so I mounted the tank between that and the rear shock mount using tabs. I made it so everything was easily REMOVABLE. Here are some pics.

The first pic is how it sits under the rig.
I ended up cutting a portion of the rear cargo area out so I could get the tank up higher and I made a new deck over it. I ran an internal pump and dropped the pick up into a sump (on the bottom). It was gonna be an engineering feat to plumb the filler to the stock location, so I ran the filler neck between the frame rail and the bottom of the tub and turned it UP and came through the fender well to an after market filler. Ill admit...it was a ROYAL PAIN IN THE ASS to make it all work. Now that its in and done, I ended up with 17 gal tank, low, centered fuel weight, which I think will be nice and also freed up a TON of storage space. Im going to ADD a 1/2 think ridge across the top of the wrap bar x member JUST IN CASE. Id be F*CKED if that x member gave way, so I dont wanna take any chances with that going south.

HTH!

 

[Davs]

Thanks Chicago. It's pretty funny... I was just reading your thread the other day and admiring your fuel filler (is it from a boat?) and all the joys you were having with your tank!!! Your setup looks brilliant, and pretty hardcore! My fab skills are average and no mates to help out, that's why I'm looking for an 'easier' option! Does your exhaust run close to the tank?

 

[chicago]

Thanks Chicago. It's pretty funny... I was just reading your thread the other day and admiring your fuel filler (is it from a boat?) and all the joys you were having with your tank!!! Your setup looks brilliant, and pretty hardcore! My fab skills are average and no mates to help out, that's why I'm looking for an 'easier' option! Does your exhaust run close to the tank?

I got the fuel filler from summit racing, and I do believe I may be for a boat application.
The exhaust will run along the driverside frame rail. I left a "chase" of sorts for that to run, so it will be several inches away from the tank.
Did you find a tank to fit? The nice thing is there are ways to re mount the shock pins both on the rear x member and and on the axle. If you can find something to fit, that is 90% of the battle. There were a few jeep tanks that were close to what I needed, but for "legal reasons" it was hard to get info. Gotta love lawyers.

 

[FishNinJay]

Hey kids, I need some opinions and any legals about fitting a fuel cell under the body/above the rear tailshaft?
I think i would have to mount the fuel cell cradle through the floor at one end and to the rear crossmember on the other end.
The fuel cell is 177mm (7") tall, 760mm (30") wide and 430mm (17") deep. It would fit nicely between the chassis rails and crossmember and the height is no worries either.
My problem is that I would have to relocate the rear shock mounts to under the crossmember and the exhaust pipe would run very close to the fuel cell.
Anyone have any alternative suggestions or issues I might run into?

Hmm.. seems we have similar set-up. I have a 350, TH400.. Why above the shaft? Just wondering..

I just dropped my rear aux tank to clean out the gunk and install a fuel sender (and I have a rear bench seat project so I need access for mounting bolts). Here's my set-up.. this was a custom tank that came with my rig.

 

[Davs]

Hmm.. seems we have similar set-up. I have a 350, TH400.. Why above the shaft? Just wondering..

Ideally i would run the same tank setup as yours ARC1, but i cannot find anyone in Oz that sells them - which means 'custom' - which means 'pricey'! I have read Twisty's thread and he fit a similar cell behind the Xmember, where yours is mounted, but for the life of me i cannot figure out how he did it - i just can't seem to fit it there.
So basically, i was going to fit the cell in the area above the shaft because that is the only place an 'off the shelf' cell would fit.

 

[Davs]

I got the fuel filler from summit racing, and I do believe I may be for a boat application.
The exhaust will run along the driverside frame rail. I left a "chase" of sorts for that to run, so it will be several inches away from the tank.
Did you find a tank to fit? The nice thing is there are ways to re mount the shock pins both on the rear x member and and on the axle. If you can find something to fit, that is 90% of the battle. There were a few jeep tanks that were close to what I needed, but for "legal reasons" it was hard to get info. Gotta love lawyers.

This was the tank i was thinking of. It should fit nicely but i don't think there will be enough gap between the rails for the exhaust. I think i will be able to retain the original filler point though.
As far as relocating the shock pins, do you see any problems or have any suggestions about moving them to below the Xmember?

 

[chicago]

Not really, but you'll be limiting the travel of the shock that route. Kinda sucks IMO. However, that may not matter to you, either.
I was looking at that tank at some point too. Don't recall the issue i had w it though. Old age setting in at 37.

 

[Davs]

I was looking at that tank at some point too. Don't recall the issue i had w it though. Old age setting in at 37.

You can't do that!!! You can't tell me that there was a reason for not using that tank... but not remember the reason!!!
I was thinking something like this for the shock relocation solution... would this still limit the travel?
Cheers for the help by the way.

 

[Davs]

Well... I think I now know why you didn't go down this path!!!
I'm a 'swear word' idiot!
I think I'm going to start a thread called 'Everything NOT to do in your FJ40 build'! So now I'm screwed! It's already got a 2" body lift and I had to cut and flip a section of the floor to give it more clearance, does anyone have any other ideas?

 

[chicago]

Well... I think I now know why you didn't go down this path!!!
I'm a 'swear word' idiot!
I think I'm going to start a thread called 'Everything NOT to do in your FJ40 build'! So now I'm screwed! It's already got a 2" body lift and I had to cut and flip a section of the floor to give it more clearance, does anyone have any other ideas?

Ouch!!!!!!
SOA time??? Severe bump stops???
The good thing is that it's steel tub, so you can cut it back out and re do it.

What are your plans w this rig? How do you plan to use it?

 

[Davs]

Ouch!!!!!!
SOA time??? Severe bump stops???
The good thing is that it's steel tub, so you can cut it back out and re do it.

What are your plans w this rig? How do you plan to use it?

Can't SOA, the laws in Australia suck! If I can't come up with any other options, I think I will have to go the bump stop option, I would only need to extend them an inch.
I don't have any real plans for the 40, it needs to be somewhat of a daily driver and do a bit of offroad on the occasional weekend.

 

[yzftaco]

Can't you take the tank off, and cut out clearance for the pumpkin, and have a certified welder put it back together for you?

I'm planning on doing this. My axle is moved back 6" and don't think the Aux tank I have sitting in the garage will fit without some trimming..

 

[Davs]

Can't you take the tank off, and cut out clearance for the pumpkin, and have a certified welder put it back together for you?

I'm planning on doing this. My axle is moved back 6" and don't think the Aux tank I have sitting in the garage will fit without some trimming..

I could cut-and-weld the tank but i was trying to avoid that - due to where the sender is located and it would be nice to have a fuel gauge that was accurate though.
If my rear axle was moved back a few inches it would clear it no worries - but i can't get my head around the easiest (legalist) way to do it!

 

[chicago]

I could cut-and-weld the tank but i was trying to avoid that - due to where the sender is located and it would be nice to have a fuel gauge that was accurate though.
If my rear axle was moved back a few inches it would clear it no worries - but i can't get my head around the easiest (legalist) way to do it!

There's nothing illegal about moving the rear axle back, is there?
That'd be a whole can of worms to get into though.
Might be able to flip your springs to set that axle back a couple inches.
Damn...that's a tough one.

 

[Davs]

Did i mention that i have already flipped the springs?!
I know that there are numerous threads on this topic but are there any springs that will set the axle even further back than the spring flip?

 

[chicago]

Did i mention that i have already flipped the springs?!
I know that there are numerous threads on this topic but are there any springs that will set the axle even further back than the spring flip?

FJ60 spring will new about 2-2.5 in if flipped. Youll have to re drill the mil. wrap leaf if you wanna keep the mil. wrap in its correct location, and you will also have to get new hangers because the 60 series springs are WIDER than the 40 springs. Once the hangers are off, you actually wont need to get springs because you can re set the rear axle all the way back to the x member if you want.
This is a compounding effect though, because then you might need a lengthened drive shaft, might need to cut the rear fender well to clearance the tire etc. Is this tank worth all the effort at this point? I was having to do all this crap any way, so it was all the same to me, but...you have a functioning rig that is pretty much stock. It seems like a lot of work for not much gain. Only you can answer that though.
You can just cut out the floor pan a bit and bring it up higher? Doesnt sound like youll be THAT hard pressed for the storage space.

Here is a pic of the cargo area. I had to clearance as well into the cargo area to get mor height out of the tank. I just bent up some sheet metal and essentially made a box to cover the end that had to come up and welded it all together back to the tub. You could conceivably do the same but just take the whole thing UP into the cargo area.

Another option is just scrap it and stick with the stock fuel tank? Youre limited by the laws there, it sounds.

 

[Davs]

Thanks for the suggestions Chicago. The rig isn't that stock anymore cause it's just a hobby and I wanted to build it so that it was a bit 'different', so the sky is the limit... as well as my wallet and the legalities!!!
I think I need to extend the tailshaft already and trimming the wheel wells would just encourage me to throw on some tube fenders!
I've raised the floor a bit but I could possibly raise it a little higher???
I think I would prefer to extend the wheelbase, if I could understand which method would be most practical! I don't know what springs are already on it but if i got some 2" lifted springs and moved the rear axle back a few inches, I think it would all be sorted!