h0runner

So as the title says I’ve have two fuel tanks give up the ghost in the past three months. Oem tank lasted 33 years, new spectra premium tank lasted three months. Cracked in nearly the same location, bottom of the tank where the weld around the drain plug is, and bottom of the tank where the fuel pick up baffle is spot welded to the bottom of the tank. You guys think this is a fluke? Just bad luck? My 4Runner is long travel and it is driven hard but it hasn’t really been beat on since I replaced the tank. Has maybe 60 dirt miles and most of those were smooth roads with the occasional hard hit. It’s basically stock except for upgraded diffs, suspension, and solid mounted drivetrain. I have a new tank waiting at the parts house cause spectra premium warrantees for three years. Just kinda stumped why this happened again. Also no, no rocks or logs have jumped up and punctured, it’s a crack.


any idea yotabros? This is weird and have never heard of this happening to anyone. Thought about rubber mounting the tank, kinda how a Dirtbike does it, but that’s just one more thing to worry about wearing out and failing when I’m miles and miles from civilization. Also would probably need longer bolts and to double nut them on the other side of the tack welded bolts on the frame.

wallytoo

iTrader: (1)

probably just luck (or bad) of the draw, especially nowadays. the spectra premium tank i installed in mine in 2013 is still working after 120k miles.

akwheeler

the words "solid mounted drivetrain" are a red flag to me. Probably too much vibration at just the wrong frequency or flex in the chassis from engine torque that would normally just flex the engine/trans mounts.

h0runner

yeah I’m really hoping it’s just bad luck. New tank is currently hanging in my garage with the rubberized undercoating drying, gonna throw it in tomorrow morning and hope for the best, if the coating is dry. It’s pretty much still winter here in SoCal, in the 60s and heavy cloud cover with high humidity. Then it’s on to rear wheel bearing replacement lol

I mean, a lot of people do it. The motor mounts on these are a well known weak link, especially for those of us that off-road a decent amount. Maybe these trail gear mounts just vibrate worse than others? Might try ruffstuff, heard those are a lot more smooth. I have bad vibration from 1800-2800 rpm. Like mirrors aren’t usable because the vibration is so bad. Maybe the fuel is acting like an amplifier for the vibration? I don’t know much about fluids and vibrations so I really have no idea. Chassis has no cracks and doesn’t flex much, has the big oem cross brace for the trans and I made a 1.75x.120 tube cross member with gusset tubes behind the axle to mount my rear shocks to so that probably stiffened it up a lot back there. I’m kinda stumped as to why it cracked again in almost the same spot on a different tank.

hurricanes

I got a Spectra Premium tank a few months ago too, hope it wasn't a bad batch!!

h0runner

I hope not too. This new one looked a little different and was absolutely covered in what I’m guessing is the thick grease they use when stamping it, maybe flux paste if they dip them? Either way it’s finish it a little different.

rubberized under coating didn’t work very well, was crumbling off as I was working. It’s probably too cold or humid to dry, it’s 55° and raining out this morning. Anyway it’s in and has a few gallons in and the truck runs so I’m gonna say success so far. Still curious if anyone else has heard of this happening or has had this happen themselves. Super weird situation! Hopefully I don’t have to drop the tank again for a while.

h0runner

Welp another spectra premium tank cracked on me, in the exact same spot as the last time. Once again covered under warrantee but I still have to spend an hour or so swapping them out. Lasted a little over a month. Kinda baffled, can’t really think of any reason other than my solid motor mounts are creating so much vibration it’s causing it to crack at its weakest point? I put solid motor mounts in around June of last year, by January I think the tank cracked, kept smelling fuel for a while but didn’t think much of it till I noticed drips around March, that’s when I swapped the first one, then again in June, now again this weekend. Nothing else on the truck has changed in that time frame other than motor mounts. Crawled around for about an hour last night and don’t see any cracks anywhere on the frame so it’s not being stressed that way. Kinda stumped.

millball

Can you find a professional shop that boils and repairs tanks???
Perhaps a professional could drill a couple stop holes at the ends of that crack and silver braze a spot over it.
A braze patch would be more flexible than the worked steel tank is.

Warning!!!.... Do Not Try this at Home.....

h0runner

Id just do it at home or have a buddy tig it, but if it’s cracked on the HAZ three times before, I don’t know if introducing heat to it again will have the desired outcome. I have my oem tank that’s been empty for months, thinking about tig welding the crack and putting that back in. I’ve already got new oem motor mounts that I’m going to “MarMod” cause those won’t vibrate like the trail gear mounts I have.


also yes do not try this at home if you’re not a competent welder or understand flammable fumes

millball

I suggested brazing because the added material is softer and more resilient than ferrous welding would be.
I see no reason that a steel weld repair would not just crack again.