I have a 2000 SR5 4Runner with 185,000 miles.

I have a rust problem on frame and undercarriage that seems to be getting worse. Does anyone else have a similar problem?

I live in Northeast PA and am not sure if rock salt is too blame or poor quality steal from Toyota.

I went to replace the rear diff fluid and found I was not able to because of rust. Please see attached pic.

 

It's not poor quality steel, it's poor maintenance. Not scaling rust is a maintenence issue. Once it gets so bad as in your pic, it only accelerates, by trapping more and more moisture and salt. It should have been all cleaned up with a wirebrush before the winter, and after the winter.

At this point you need to wire brush to almost a shine, and get the bolt out, then replace it with a new one.

 

It is not the salt so much but the liquid brine that is so very bad so much it is taking out the bridges.

If the frame is bad the steel brake and fuel lines unless replaced already should be interesting.

Just where in Northeast Pa

I have fixed quite a few of these things if you want a good idea of how bad it is. Let me know about a hour south of the Wyoming Valley.

If your doing your own service and let it get this bad.

 

I'm near Scranton, PA. I am not much of a Mechanic. I am learning a bit too late of how to maintain.

I have replaced the fuel line and filter. Not brake lines, yet.

 

Its bad metal treatment from toyota road salt and lack of maintenance mine is rotted so bad it porus and my gear oil leaks out

 

Not really fair to blame Toyota.

Just for the record The 4Runners were all made in Japan and did not get any of the Dana Steel

i saw one the other day that was pretty bad from the liquid brine and the lack of maintenance by theowner.

It is every vehicle on the road From Over the road Trucks on down.

To meet the Federal fuel mileage standards all automakers had to cut weight where they could.

This is also what gave us these front wheel drive cars saying weight to meet mileage standards .

The liquid brine is a real killer just so every one can go outrunning around.