Five problems related to power train driveline have been reported for the 2001 Toyota 4Runner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2001 Toyota 4Runner based on all problems reported for the 2001 4Runner.
2001 Toyota 4runner rear axle housing rot/leak, no signs of abuse.
My 4runner's rear differential has pinhole leaks due to rust. The rest of the vehicle is in excellent condition and has been very well taken care of including chassis washes at least twice a week in the winter.
The rear differential is rusting through to the point of leaking oil. I suspect the differential is corroded to the point where is mechanically unsound and could cause a catastrophic failure if hit by a rigid obstacle in the roadway.
My 2001 4 runner with only 125,000miles has a rusted out rear differential. This was shocking to me because my truck is in otherwise excellent condition and has absolutely no rust on the body. I took it to Toyota who said they can replace it for $2200 plus tax. I took it to my husband's mechanic to repair/patch it if possible. He said he has seen many vehicles with more miles than mine in much worse condition that have no rusted out rear differentials. He found it very unusual. He said the metal housing is very thin (from the factory that way) which is the root of the problem. The mechanic welded a patch over the hole; however this is not a good permanent fix for the problem. It also makes my 4 runner have next to nothing for trade in value for a truck that otherwise would have a nice trade in value. This makes it a double insult. . Read more...
Rear differential housing rusted through. This caused loss of lubrication oil, required the replacement of the entire differential housing. Thin metal and lack of rust prevention are the cause.