How do I repair a rusty automobile frame?

I have a 93 Pathfinder with a rusty frame, I just discovered that the rust has eaten a hole through the frame and I'd like to repair it.... how do I go about it??

Gorfram4 years ago
 Burf and R-d are quite right - for every rusted-out spot you can see there are 10 that you can't (rust can be very sneaky stuff). Basically, you have two choices:
  1. Take it to a qualified body shop and have it checked out, and then repaired (or even replaced) as necessary.
  2. Do nothing, and/or try to fix it yourself; and then keep driving around in it until the day you get into some sort of collision and the frame crumples up like an empty candy wrapper. Only it won't be empty - you'll get to be the creamy filling inside.
I know that sounds harsh as hell, but that's because it is harsh as hell: one collision and this will be a very literal matter of life and death.

wbrennan4 years ago
 I have a 95 with some frame cancer as well. I've found so far that the rust in the frame portion seems to be worst at the underside (IE the outside part, closest to the road). There are no problems with the body mounting points other than some scaling (IE surface rust). I've found that my 4" grinder, my unibit, and a screwdriver along with my hands are an effective way to check any problem areas.

I don't agree with the current best answer unless you have a friend at the body shop who could look into it for free. Ultimately you will just be paying someone to confirm that "yes, it's going to cost you a lot of time and money to fix this".

I also don't agree with "the frame crumpling like a candy wrapper", at least not on this vehicle. It's a fully boxed frame, the bumper is solid steel (sometimes even chromed), and on mine there is an external tubular spare tire carrier that connects the body to the bumper. Most Pathfinder owners also have a hitch. That's quite a lot of steel to "crumple". Then there is the actual body of the vehicle, which looks like a tank and again, is very solid and steel.

What you can do is what I plan on doing with mine. Stop the rust using some form of anode/cathode protection. Canadian Tire sells a kit that does this, like the video shows:

You can go one additional step and actually fix the problem areas and protect them permanently(there are tons of different ways to do this, just to an internet search for rusty frame repair) this method is the most basic:

And, if you're going to tackle this problem, be persistant, as rust never sleeps. Just be thankful that there is only one hole in your frame, and not a whole section that needs replacing like this fellow from the Nissan forums:

Lastly, don't get discouraged; if you find you're in over your head you can get help from a welder/fitter or even part it out as someone suggested and get some of your money back.

Good luck!

In response -
I don't agree with the current best answer unless you have a friend at the body shop who could look into it for free. Ultimately you will just be paying someone to confirm that "yes, it's going to cost you a lot of time and money to fix this".
A reputable body shop should be able to tell you something like either:

1) "The rust-through is in a structurally critical place, which means that if you were in a collision it would be almost as if that part of the frame weren't even there. Your vehicle is unsafe to drive. The good news is, if you stick around until the end of my shift, I'd be glad to give you a ride home."

2) "None of the rust I could find is in a structurally critical place, which means you might be okay. Our shop doesn't do that kind of work because of the massive liability problems it could cause; but you might be able to to find someone to clean & patch it up for you, or you could try doing it yourself."

There's probably some flat fee a shop charges for checking out a frame with doing any work on it.

I also don't agree with "the frame crumpling like a candy wrapper"...
It's true, you could drive around for years in a car with rust holes in the frame and never have a problem. Maybe you'll never be in a colllision. Maybe you'll be in a collision, but not one bad enough to break the remaining structure of the frame. Maybe the frame will have just enough strength left to absorb the impact forces without passing the brunt of them on to your very breakable human body.

The question is, are you willing to take that risk?

Wbrennan is, and he's willing for you to take it on his say-so. I'm not willing to take such a risk, and I'm not willing to recommend that anyone else take it.

Coal mining, military combat, Russian Roulette, and golfing in a lightning storm are probably riskier. Cave diving, rock climbing, Alaskan crab fishing, and TP'ing the home of your local organized crime boss are probably safer.

It's your decision.

Part it out?  Put it up on blocks in the back yard and use it as a playhouse, chicken coop, or guest room?

I'm skeptical that it's worth fixing if you have to pay anyone to do the work.  And if the frame is that bad, the body is likely to be rusty as well.
Re-design4 years ago
Check the link to see what happens when your frame is not as strong as it used to be.
Burf4 years ago
Initially I was going to suggest some de-rusting, grinding and a welded patch, but apparently, frame rust-out is a rather serious problem with 93 to 95 Pathfinders. Serious enough, that it would probably be in your best interests to take it to a body shop and have it thoroughly checked by a pro.  If it is minor, then you can consider making the repairs yourself. If not...

Google "93 Pathfinder rusted frame"

Re-design Burf4 years ago
I agree!  Frame rustout is serious business.  If you've got a hole that you can see then you can be absolutely sure that you have more rust in places you can't see and in an accident you aren't going to have the protection that the frame is supposed to give you.

You should have this checked soon to see how much damage there really is.
jeff-o4 years ago
Dunno - you'll probably have to get a body shop to weld a few plates on there for you.

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