Hi all, it's my first time here, just found this forum and Ihave an '02 4Runner with a rusted out rear differential housing.

I was noticing the smell of gear oil at the rear of the truck and crawled under to take a look. The bottom/rear of the differential housing was wet, and at first I thought maybe the drain plug was loose, although I have never touched it. Upon closer inspection it appeared that the oil was leaking out from the rear of the differential casing, in an area where there are no seals, seams, drains, etc. It was pretty rusty and covered with scale, after I chipped away all the scale with a pick hammer a drip started.

I still find it hard to believe, but the netal had actually rusted through and there are a bunch of small pinholes where the oil is leaking out. The metal is so thin that a few gentle taps with a punch makes a hole. This is my 4th Toyota truck and while I've resigned my self to accepting the inherrent body/bumper rust issues I have never seen any rust through like this before.

So, my question is has anyone else here experienced this? Obviously the warranty has long expired but if anyone else has been here, were you able to get any help/goodwill warranty from Toyota? I'm not looking forawrd to replaving the entire rear axle housing and swapping over all the beakes, suspension, etc.

Any suggestions?

Thanks,

Mark

 

Depending on where it is etc.. A plate or trail armor type plates can be welding on after stripping the diff done to nothing and then a good rust preventative and prime and paint job will keep it from happening again.

 

I have the EXACT same problem. 2002 4Runner SR5 with a rusted out rear diff cover.

Hey jtimports: Could you give a little more info on the options you mentioned. Specifically, is there an aftermarket repair or replacement part that will help with this?

scargo: Let us know if you find a solution. I will do the same, although right now it looks like a replacement diff (or at least the housing) is the best way to go.

My transmission guy says he has had success with brazing a home-made cover over some diffs. with this problem.

hth,
-T

 

wrecker should have one. then put it in. that is the beast way to know you ride.
work on it your self.
I was going to put new diff centers front and rear in mine for $1200
the gears are a little bit low for road use but i think i can live with that
good luck
be safe

 

V84Runner: Thanks for the input. I understand your attitude about getting a replacement, but it sure rubs me the wrong way to have to do $1000+ in replacement work for what could have been avoided with $1 more in steel at the factory. Nuts!

 

Same rusty/leaky diff problem on my 2000 SR5, 140,000 miles. Sucks that the vehicle is generally so great otherwise.
I drained the diff, cleaned it really well with brake cleaner, used coarse sandpaper to get the metal bright, cleaned it again, and epoxied up the leaks with a product I picked up in my local parts store (can't remember the brand, but it was a 2 part mix, rated to resist gas, oil, and high temps. It's black).
Smeared it thickly all over the leaky places, let it set overnight, and I've been good to go for a few months already. Had to fix a few new pinholes that started leaking, but none of the repaired ones have leaked again.

When it gets warmer I think I might just epoxy the whole damn thing. Looks like hell under there now, but it's working and the spare tire hides it!

 

have the same problem. i just don't know about the best way to remove the rust and i really hate to seal it underneath the paint. got noticed a lot of rust on the rear axle.

 

I just found the same problem on my 99. The dealership suggested that i try the same thing that SteveKNY did using an epoxy to fill the rust holes. Sorry, I didn't get a product name for the epoxy. If I find some I will post it.

 

Hi all

I have read that several of you have 4Runners with rusted out rear differentials. My 2001 has the same problem. Does anyone know if this is something Toyota is aware of and if they are doing anything about it? Have they corrected the "faulty thin metal" on newer models? I am possibly interested in a new Toyota 4Runner or Sequoia. Does anyone have information about the newer models of these 2?

My 4Runner has 125,000 miles. My husband who has had several vehicles in his life (none of which were Toyotas) says he has never had one do this. He has had several for 200,000miles plus.

Toyota wanted $2000 to replace the rear differential. I ended up taking it to my husband's mechanic who chipped away the weak rusted metal, welded a plate over it and covered the entire housing with Epoxy. I just picked it up last night. It looks good. I will see how long this lasts.
By the way, the body of my truck has absolutely no rust, so I was a bit shocked. I do live in the north where they use salt on the roads in the winter and I park in a garage daily. I am sure this doesn't help, but I thought Toyota was known for quality.....

 

I just had the differential housing replaced in my wife's 2001 4Runner on 4/29/2009. I've restored classic muscle cars for 30 years and have never seen anything like this. The rear cover rust was peeling off in 1 sq. in. flakes. Epoxy is a very temporary remedy and welding was out of the question as there is not enough metal thickness left to weld to.

The replacement housing, with labor, was $1400. Toyota has offered to make a "goodwill" adjustment, but has not come up with a dollar amount yet. Bad steel and paint prep are to blame.