tube steel crossmember rotted by gas tank

I have some rot in the round tube steel cross member between frame rails near the rear of the gas tank. This crossmember supports a bunch of stuff like the upper suspension links, gas tank, etc. Mine is rotten towards the middle and has developed a crack. What I want to do is just slide a smaller diameter tube right into the existing tube, throw a couple welds in there, and call it a day. The existing tube is not in the worst of shape, it is just really banged up in the middle by the crack. I searched and was surprised that this repair has not been discussed before. Has anyone else had to do something like this?

You should take a picture and upload it so we can see and tell what can work or not.

NJ-4Runner said:

I have some rot in the round tube steel cross member between frame rails near the rear of the gas tank. This crossmember supports a bunch of stuff like the upper suspension links, gas tank, etc. Mine is rotten towards the middle and has developed a crack. What I want to do is just slide a smaller diameter tube right into the existing tube, throw a couple welds in there, and call it a day. The existing tube is not in the worst of shape, it is just really banged up in the middle by the crack. I searched and was surprised that this repair has not been discussed before. Has anyone else had to do something like this?

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[MENTION=164664]brillo_76[/MENTION] has done it. He's the man on fixing up these frames. I believe he has done just as you mention. Check out his build section.

Yup use a black steel pipe 43 inches long with a close to 2inch outer diameter. I clean the old cross member tube out. then coat it with FF and slide a new one inside. Once that done. I weld it on the ends and then Weld the brakets to it in the thin spots. As brackets can be welded to the new inner pipe super easily.

brillo_76 said:

Yup use a black steel pipe 43 inches long with a close to 2inch outer diameter. I clean the old cross member tube out. then coat it with FF and slide a new one inside. Once that done. I weld it on the ends and then Weld the brakets to it in the thin spots. As brackets can be welded to the new inner pipe super easily.

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You mean like a regular schedule 40 black steel pipe for plumbing natural gas? Is the 2” black steel pipe a nice tight fit?

NJ-4Runner said:

You mean like a regular schedule 40 black steel pipe for plumbing natural gas? Is the 2” black steel pipe a nice tight fit?

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Yes... Its slightly smaller but welds in greatly.. being the rust will swell. I use black pipe like natural gas plumbing 1/1/2 inner diameter... which is close to 1/4 ich thick is super close to 2 inch outer diameter slightly less then that but close.

IF you have find a pipe a little closer that steel it will work great. This is the closet pipe that i came across easy to get ahold of that works.

brillo_76 said:

Yes... Its slightly smaller but welds in greatly.. being the rust will swell. I use black pipe like natural gas plumbing 1/1/2 inner diameter... which is close to 1/4 ich thick is super close to 2 inch outer diameter slightly less then that but close.

IF you have find a pipe a little closer that steel it will work great. This is the closet pipe that i came across easy to get ahold of that works.

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Right on thanks! From my rough measurement I will need about a 2-1/16" outer diameter pipe. I may actually hit up a fabrication shop this weekend. I am gonna pull into the parking lot, take a rear tire off, and just throw pipes in there until I find one that fits the best!

NJ-4Runner said:

Right on thanks! From my rough measurement I will need about a 2-1/16" outer diameter pipe. I may actually hit up a fabrication shop this weekend. I am gonna pull into the parking lot, take a rear tire off, and just throw pipes in there until I find one that fits the best!

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The chances of you getting a 2 and 1/16 OD pipe to go through a rusted tube cross member is extremely unlikely.

I actually had to pound my pipe in with a sledge to get it in as they rust and rust expands the rotting steel.. hence why I dropped the size slightly.

brillo_76 said:

The chances of you getting a 2 and 1/16 OD pipe to go through a rusted tube cross member is extremely unlikely.

I actually had to pound my pipe in with a sledge to get it in as they rust and rust expands the rotting steel.. hence why I dropped the size slightly.

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I ended up getting a piece of 2" outer diameter steel pipe from a local steel supplier. Are you ready for this......the walls of the tube are 1/2" thick! They had it laying around and I paid $30 for it. Like you said the frame was in bad shape inside and there is no way it was simply going to go through. So I reamed out the frame with a 2" diameter hole saw to clean up the rust inside. Then I greased up the new pipe and rammed it through. I also had to use a sledge to get it through. I didn't have to pound on it as hard as I could but it definitely needed some force. I put a couple small welds on the end, probably didn't even have to do that.

So in the end a 2" outer diameter pipe would probably go right through if the existing frame wasn't already that damaged from rusting on the inside.