Hi,

I took my 2000 4Runner to the Dealer today because there was a slight leak in the rear differential. To my amazement, I was told that I had to replace the entire differential because the oil was seeping through the metal due to rust. and it could not be fixed. First of all, I have never heard of this happening before until I went on line and there seems to be a huge problem with Toyota and this very issue. The truck has about 120,000 on it but it has never been submerged in salt water. I have just never heard of this happening before.

From every Diff I have ever seen, there is a cover bolted to the back of the diff. I am told that this is all in one piece. I was also told that because everything is rusted together, other parts may get broken along the way. If it goes perfectly, it's just over 2,000. If everything breaks on it, 4,000 would be more of the reality.

This truck runs perfect. It has never not started, the paint is in great shape, I just spent a little over a grand for a new exhaust system and it has about 800.00 worth of tires I bought last year. So clearly, getting rid of this truck is the last thing I want to do. I am very confused on how to handle this.

I don't want to screw around and try to patch it or weld it because so many people have said that it is only a temporary fix. It comes down to fixing it the right way or getting a new truck. I did read that one person that has this same problem is dealing with Toyota a they are telling this guy that they would work with him on the replacement cost because this is a well know Toyota problem that should not be happening.

So, any ideas are always welcome.

 

I had a 2001 SR5 with two or three pinholes of rust on the rear diff at the back-side. This is not a cover as I understand it, but a one-piece rear axle. The "cover" is the front part of the diff at the end of the drive shaft.
Anyway, I had rust perforations. I have read that some have had good success by thoroughly cleaning the affected area, and, after draining the diff., then using JB weld or other two part epoxies to seal up the holes. I did not repair it. There is not enough thickness to braze or weld the affected area, and I thought it was risky since the rusted area could spring more pinholes and leak elsewhere on the diff. The proper way was to get a re-cycled rear axle. This was going to cost me upwards of $1500.00 installed. The rear axle alone was something like $650.00 shipped up to Canada from the Southern US. All else on the truck was fine except for this lousy rear axle/diff.
I had a 1997 prior to the 2001, and it did not suffer from a rusted axle/diff.
I choose to trade the 2001 for a 2002 Ltd., in better condition and with 100,000kms less on the clock.
I hope this helps.