First off, I paid $6900 for a 2000 4 runner 4wd, v6. Engine and interior in perfect condition.... so what's the catch?

Well, the underneath is rusted. Badly. Can't change the fuel filter b/c the nuts/bolts are rusted that looks like a weld. Will need a workaround for that later...

biggest question is rear axle, differential housing. i don't hear any weird noises or anything, and everything works perfectly. I would like to change all the fluids and do typical maintenance on it. The bolt on the rear diff is rusted and i have not even attempted removal. Flakes of rust (a few millimeters thick) you can actually pull off the rear diff. it's in bad shape. Here are some pics, but most of the rust i've pulled off (seriously).

I am thinking of just replacing the rear axle completely. I think i am using the wrong terminology, so whatever i'm search for is not pulling up. Is this not the rear differential? How do I go about getting a new one or at least a new housing? Should I replace the rear axle as well?








UPDATE! Success in removing stuck bolt! I bought the Irwin Bolt removal toolkit off amazon.com (in 24mm) and used a large breaker bar to get it off. My buddies electric impact wrench wouldn't budge it. Fluid was pretty bad, but not many shavings on magnetic bolt. Here are some pics:



New Fuel Filter i installed:


transfer case: already changed this fluid. bolts came out easy, and it was relatively clean.


Diff bolt out, tools used: breaker bar, 24mm bolt-out socket, aero kroil penetrating oil


New bolt, messy driveway! I had a bit of a hard time getting the magnetic bolt out on the bottom, but damn when i gave (i used the impact wrench) i was not prepared for the bolt to come completely out.

I am so thankful that I live in Arizona!!

thats all surface rust mines the same way. if you want it all gone sandblast it

how about attempting to back out the fill plug on the rear diff? looks too rusted and would HATE to break it off in there. Do you know of any fuel filter work arounds? I don't think it's possible to replace the fuel lines w/ flexibles (even though i've searched everywhere for them) and the nuts on the fuel lines are bonded to the filter.

even toyota dealership told me that they wouldn't attempt the filter

It "Looks" pretty ugly down there but might not be as bad as it looks if that makes any sense. How many miles are on it and what option package is it?

If it drives nice and nothing is falling off I would likely just leave it as is and drive it until something important actually does break and fall off. Do you know the history on why its so rusted down below? Looks like someone drove it in the ocean but it could just be from a snowy place where they use lots of salt. Japanese steel rust pretty quick.

As for the rear diff drain plug I have seen worse and people have removed them. Might try a penetrating oil like PB Blaster first to clean it up. You might have to take your time with it though.

angle grinder with a wire brush wheel will take most of the rust off. then spray paint the parts to provide a tiny bit of protection.
and buy a few cans of pb blaster. it will be your best friend when working on rusted out bolts

x2 on the Pb blaster, couldnt of changed the 3rdmember w/o it

Use naval jelly to help you with the rust removal.

and when you're changing your differential fluid

:awais:ALWAYS REMEMBER TO REMOVE THE FILL BOLT FIRST:awais:

the fill plug is the one you see when you look at the diff from the rear of the truck, located on the side of the housing.

You may be wondering why I say this. Well, if you take the drain plug out first, and then the fill plug breaks in ther housing, and you can't replace the fluid, you'll know exactly why...

thanks for the replies guys. It's a 2000 sr5, with about 126k miles on it. it was a northern vehicle, but i purchased it in louisiana. i did not take it to a toyota dealer first before i bought it (kicking myself for that), but bought it at a dealership there.

i will do some rust remediation this weekend if i can get away with it, and i will definitely take the fill bolt out before i take the drainplug out. I'm going to get an extra fill plug just in case i destroy this bolt.... looks fragile.

other than the rust (interior is perfect, as is exterior) the truck is great! OH, and i have that stupid gas gauge issue.... grrr... not too worried about that. gonna do a spark plug and fluid change and will post pics of the underside when i clean it up a bit.

where though would i buy parts like the diff case and axle and all that? i have searched everywhere...

thanks guys!

This might help some with the fuel gauge issue when you decide to tackle it. I had the same problem.

http://www.yotatech.com/f2/fuel-gauge-issue-163080/

how long has it been in louisiana?
could it have been a katrina car?

Me too!

no chance. the owners had moved to louisiana back in 07. that's what the carfax said at least.

i did the reset thing yesterday at work, but haven't tried to change out any parts yet... i figure the fluids are more important, but i like driving a perfectly operating vehicle so it will be fixed