'02 4Runner rear diff rust out
 

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

RE: '02 4Runner rear diff rust out
 

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.

RE: '02 4Runner rear diff rust out
 

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

HI
 

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
:)

RE: 4Runner rusted out rear differential cover
 

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!

Rusty differential housing
 

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.

rusted out differential housing
 

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.

2001 4Runner with rusted out rear differential
 

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.....

2001 4Runner Rear differential rust thru
 

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.

Hi Mark

I recently found this sight. I have the same problem with rear differential housing rust out on my 2001 4 runner. I went to the goverment official complaint site to log in a complaint. The site says it will review complaint and if they see a trend will have the manufacturer look into it/fix it. The site is down for repairs until tomorrow. i plan on filing on official complaint for this problem. There is already one there from 2008. Please go to the site and log in an official complaint as well. If we all do so, maybe Toyota will see there is a trend and will do something to help us out.
The site is www.nhtsa.gov It is the official site of the Office of Defects Investigations. A contact phone # if you want it is 888-327-4236. Please file an official complaint if you have not already done so.

Good luck. Hopefully, we will see some results.
smilesbd

Everyone,
Bad news from Toyota. The will NOT help with any goodwill adjustments of any sort on 4Runner differential rust. I must say that I am very disturbed by this rejection. The only recourse is thru the NHTSA Complaint process. If you have this problem, notify the NHTSA. There are 2 complaints on record now.

01 4-runner diff rusting
 

Hi,
I also came across this thread. I too have a 4-runner with the rear diff rusting out with a pin hole leak dripping oil. The location of the rust hole is on the bottom part of the pumpkin. The dealer tried to check the oil level in the differential but couldn't get the fill screw out because it was rusted-in and couldn't be moved. When they tried tapping the fill screw it with a chisel and hammer the rust leak got worse. They squirted some RTV in the rust hole as best the could and said dont take it on long trips. The truck is a 2001 and has 122K miles with eight north east winters on it. So much for the 100K mile warrantee. I have never had a car or truck do this. The dealer customer reps are both on vacation till Aug. 13. Let's wait to hear what they have to say. :(

rear differential cover leaking fluid
 

I've got the same problem on my 2000 Toyota 4Runner SR5, and it's been leaking for at least 2 years as far as I know. The entire cover is rusted and the fluid leaches right through the metal.

I called a Toyota dealership today and was told by the parts department that they do not even sell the cover separately, that you have to replace the entire rear differential housing, at a parts cost of at least $1000. (The actual range was $1000 - $1105, depending on model). I filed a complaint at www-odi.nhtsa.dot.gov today (thanks for the info, smilesbd!), and found 3 other complaints that were identical to mine. Hopefully if nhtsa gets enough complaints it will initiate a Toyota safety recall, as the rear differential could lock up and cause an accident (not to mention dripping fluid onto the roads). If you haven't already done so, please file a complaint either via telephone or online if you have the same defect (or any others, for that matter). The more complaints that are filed the faster it'll be addressed!

Thanks btw for giving the site, it was quite helpful for those who had complaints to Toyota and their 4runners... I also had the same problem as yours...

This defect is inexcusable! Shame on you Toyota!
 

I wish I had come across this forum a couple of weaks ago. I thought I had a unique problem. Appearantly not.

When I asked my local dealer if my leakage was unusual, they told me that they had recently replaced several rear axle housings due to leaking pumpkin housings. This appears to be a widespread issue. I was quoted $2K to $3K for replacing my rear axle, and just over $1K to hand me a new axle housing and fix it myself. So far I have tried a "peel & stick" repair that did last a few days, before oil forced it's way out. Has anyone had a problem with the breather not functioning, possibly allowing pressure to foil cheap repairs and increase oil loss? If the housing is rusting so easily, maybe the breather is crappy too.

YES!! The breather was not functioning. Rusted solid as a brick. Removal and light massage between a hammer and hard place made my breather fully functional again ($12 toyota's not getting today). The soft-foil backed, peel and stick, tar based product I used, sticks like hell, but because of it's flexibility is not able to deal with oil pushing out against it. Except for the small leaking area , my patch is quite well attatched to the metal. So, I will clean it up reapply a new patch, now that I know I'll have no heat generated pressure within to deal with. I just need to make it through winter, then I can look for a replacement option. Anyone have any experience with installing a shortened Dana-60 rear end(personal choice)? Any other non stock diffs? Love to hear from anyone with or wothout leaky diff problems. Have ownd my ruuner for 10 years. May have knowledge that could help you, or shoulder to cry on (virtual of course).

Disappointed 4Runner Owner
 

My '02 4Runner Ltd has the same rusty differential dilemma as those listed above. This vehicle is in literally showroom condition, 65k miles, always garaged, undercarriage always washed if used in salt conditions, and virtually NO RUST elsewhere...undercarriage, frame, components and body. In short, the rear differential housing is the ONLY rust on the vehicle. Like others, the welded brackets (emerg. brake cable & brake lines) on the differential housing appear to be where the rust originally started, and from those two points spread like wildfire. I'm not talking about superficial rust either...VERY deep rust, large THICK flaking, that has seriously compromised the housing, and has caused several pinpoint holes from which lubricant has leaked.

I repaired the pinpoint holes by wire brushing, then thoroughly cleaning with solvent, and lastly, using two part putty (marine grade) epoxy, plugged each hole. The first repair lasted about one year. I am now experiencing very slight seepage, and will remove the first crappy patching and re-do. Unfortunately, there is not sufficient steel thickness remaining to effectively weld or braze a proper patch.

My local Toyota dealer states they have NEVER seen, nor heard of, any such differential rust through. They state a new differential housing is in order... to the tune of $2K +/-. Really disappointing appreciating an initial vehicle cost of over $35K, 65K easy miles, and 100% spot on maintenance.

I have no faith in the abilities or work this Toyota dealership offers, and thus will find a good used rear end and will personally install it. I will also NEVER purchase another Toyota product (this 4Runner was my third Toyota product). Although it is of little personal consolation, I know I have successfully dissuaded at least three friends from puchasing new Toyota's. I know it may seem petty, but my outspoken attitude was the result of Toyota's glaring poor manufacturing practices and even more shoddy "after the sale" customer service. Tit for tat...

If anyone has any rusty differential success tale to relate I would love to hear from you. You can email me directly via my user name link. Yep, I've already posted my complaint to NHTSA, but I'm not holding my breath for any positive Toyota response.

02 4Runner rear diff rust out
 

I have a 91 Runner with a V6. I was slowly getting SAS parts trying to save money but with the great deals that T-G has Im just going to order the 5" SAS kit. I already have a set of 44044 springs that I was going to use up front. Ive seen a 4Runner the was running them front and rear. How much would I get if I used them in on the rear of my Runner? I want to run a 36" or 37" hummer H1 goodyears.

Me too!
 

Yep my mom just had to replace the differential in her 2001 4 Runner due to the same rust problems mentioned here. The vehicle has only 24.000 miles on it and sits in the garage most of the time. They charged her $1600. I've owned Toyatas since 1983 and have never seen or heard of such nonsense, not even with other makes. I can go to the junk yard and see differentials that have been sitting out for 30 years that are not rusted out. I called Toyota and they deny any knowledge of the problem. I feel bad because I recommended the brand to her. Can't say I'm surprised in light of the recent problems with Toyota. Never again.

Wow, $1400 is pretty steep hey? Has Toyota told you the exact amount yet? If so, how much?

Another '01 with rusted out rear diff!
 

Thanks all for your posts. I was under my '01 4Runner earlier this evening trying to locate the fuel evap canister (the check engine light went on last week and the code pointed to the canister). In the process, I found that my rear diff was rusted out and leaking, same as you've all described. It was leaking pretty good and from the look of it, it was probably leaking for a while (months) so I'm surprised I didn't catch it earlier. The plan now is to scrape away the rust to see if epoxy is even an option (might be too late) otherwise I'll end up at the dealer. It has 138,000 miles and besides the bad evap canister and now this problem, it's in great condition. What a bummer!

rust away with toyolet
 

Used to be the joke about Chev rust, now I'm crying too over the rusted out rear diff housing on my 99 4runner. I guess I should be happy that I made it to 178,000 miles compared to some with much newer vehicles with lower mileage getting this plague.
This is my third 4runner and have had two other Toyota's also, but I have been seriously shaken by this and doubt that I will buy another toy for a long time.

Just found same problem 0n 1997 4Runner Limited
 

Incredible, I just found out our 4Runner has the same problem, it is leaking oil from a point below the filler bolt. There are large chunks of thick metal flaking off the casing. Also the triangular metal piece that is welded on top of the rear Dif Axe has broken off! The truck has 134K and is always garaged and pressured washed after each winter. I can't believe it! The metal quality is terrible and then parts you are not able to replace. This is the first and most severe problem we ever had with a Toyota product. We own 3 Toyotas. I filed a NHTSA complaint because this problem, had I not noticed, could had cost our lives. I am sure Toyota will never respond to us as costumers, given the troubles they face.

Toyota's Inexcusable Defect & NonResponse
 

This post is a followup to my 1/4/10 post in this same thread. For a refresher, I have an '02 Runner Limited with 65K miles, in literally showroom condition...nope, not even a nick or pencilpoint rust spot. Always garaged, undercarriage washed if in salt, and maintained to a T. Like you other folks, I was taken aback to discover 80/90 hypoid gear oil literally coming THROUGH my rear differential housing...and even more amazed to find differential rust flakes over 0.25" in thickness, and lots of them. I have temporarily stopped the leaking with marine epoxy (three rust through holes), and halted the rust process with a complete POR-15 coating.

My local Toyota stealership still states "there are no known differential rust issues with 4Runners", and offers no explanation as to how my vehicle can HAVE NO RUST WHATSOEVER ON IT, other than the wholly deteriorated differential. A larger, and more distant Toyota stealership came to the same conclusion. Ultimately I wrote a detailed and courteous letter to the folks at the Toyota Customer Assistance Center (Torrance CA), and after over two months received a written reply stating they "could not contact me" desite professional letterhead with return address, and three phone numbers...all with voice mail and answering service. The letter stated to return a call to Toyota with an actual file number reference! I was naively optimistic.

I immediately called the Toyota rep at the number they provided with their written reply, to be put on hold for 44 minutes. When I finally reached Toyota rep "Carlos", he had to again put me on hold. Upon returning to the line, he apologized for MY problem with my "Tacoma". I refreshed him as to the correct model, and reinterated the COMPLETE ABSENCE OF ANY RUST ANYWHERE ON THIS VEHICLE EXCEPT THE DIFFERENTIAL. After again being on hold for another 11 minutes, he returned to state Toyota rust through warranty had expired on my vehicle. Again, I politely introduced the topic of DEFECT, appreciating this issue is not unique to my vehicle. His closing remark is that he hoped he had "assisted me and that my satisfaction was important to Toyota."

This is our family's fourth Toyota, and is virtually guaranteed to be the last. In my line of work, I must have 4WD as do all of my peers. I have now shared my Toyota experience with about 40 of my peers, most of whom drive Tundras, Sequoias or 4Runners. I have been in my business for over 35 years and know my peers, and they know me as being the one of the mechanically savvy car guys within the group. Jointly, they have at first marveled when personally inspecting my differential...and then marveled even more that Toyota refuses to acknowledge ANY RUST ISSUE WHATSOEVER. I know that at least three of my peers did not buy new Toyotas due solely to this sad Toyota lack of customer allegiance, and that many future potential Toyota purchases will not take place.

I will likely keep my 4Runner, closely monitoring the differential. Although not on the same 4WD plane as the 4Runner, my Toyota will ultimately be replaced with a new Honda Ridgeline...yep, ugly and pseudo-4WD...but after owning seven Honda's I know Honda stands behind their products.

Ya know, allegiance has to be a two way deal. So long Toyota, you've lost a real following of professionals who actually used to be Toyota ambassadors.

patched up
 

Follow up to my April 2010 thread above,
My mechanic said he could get a used axle housing (pre-rusted) for $1000, plus installation cost of who knows how much. No way am I spending that on a truck with 180,000 miles. So I cleaned it up, degreased and apply a liberal patch of 2 part epoxy. Two weeks later and it looks good, no leaks. I also found that the part that is rusted through appears to be a welded on rear dif cover, so it is probably not the same thickness as the rest of the housing which I would expect to be pretty heavy.
Unrelated, but I also replaced the clutch master and slave cylinders. The truck was barely driveable since the clutch was so bad. Mechanic said the clutch was shot and needed to be completely replaced. I did internet research and learned about the clutch cylinders. Works great now.
Time for new mechanic.

I just found this forum...I too am having the same exact problem on my 99 4runner and below is what I posted on yotatech.....I too will file a complaint with nhtsa

Just got back from the dealer and my rear diff is rotted thru.....2500.00 to replace....I am a very proud owner of my 99 4runner because it has not given me any major problems until today.....I have been watching the rust every year and ask the dealer if this was an issue....every year they said no....they said it was very thick metal and the rusting will not eat thru it......well....it did.......it's an 11 year old car and I do expect rusting....specially here in Massachusetts....but.....rusting thru to a point of rotting to a major component does not sit well with me......I expect rusting on the body work and under carriage but not to the differential to rot thru......something is not right.....the whole car is basically ok.....I am the first owner and it is garaged all it's life......serviced thru 2 Toyota deAlerships all its life.....I changed dealerships because I moved to a different town.....called Toyota HQ today, hoping they would offer even a discount on the part, basically I got the standard BS that you get from companies who would not want to deal with it.....they are legally out of it due to the age and mileage. 182k.......but my point is.....rear differentials should never rot thru....I will go to the dealer again tomorrow and talk some more.....I want a discount on the part.....I will pay for the labor...that's all I am after.....if they don't, Then I sadly say they lost a loyal customer in me and my entire family....I know they don't care if they lost me, but I surely feel bad about it....I am a Toyota loyalist....and I don't take that lightly......will post the outcome.

Update
 

I finally got it fixed by getting a perfect axle from a Colorado junk yard for about 450 shipped to the East Coast (WV) and my mechanic made the swap for another 500 which included many rust damaged assorted parts.. Toyota wanted 3,000 to do the work (Staunton, VA). They claim I did not take care of the underside properly by pressure washing it "daily" after travelling on snowy roads. Who does "daily" pressure washing during the winter? I'll never buy another Toyota.

I remember seeing this company mentioned in an article somewhere. Has anyone heard anything about them?


please also comment about it.

I would like opinion about CRGE, thanks in advance friends



Please also comment about it.

CRGE? What's this about?
 

CRGE? What's this about? I couldn't find a post related to the question been asked.:confused:

I followed your instructions and no leaks for over a month. The leak had just started but it was a bad leak. Hope it holds for few years now.
Thanks.
I used JB weild and also used a rust remover

when the vehicle CEL is warning you that the there is a speed sensor malfunction,it is then up to the technician to determine if the sensor is bad or there is a wiring problem.it is very unlikely for both the speed sensor and the instrument panel to go bad at the same time.I've been working on Toyotas for many years and I have yet to see both of these components to go bad at the same time.I suggest that you take your vehicle to your Toyota dealership and have it diagnosed by someone who knows what he is doing,and that has the equipment to make the right diagnosis.good luck.

Rear axle housing cover rust hole repair
 

I also had pin holes in my rear axle housing. I had estimates up to 2k to replace so I took the project on myself to repair. First, I replaced the breather plug, it was closed and would not allow pressure to bleed out of the rear axle housing. Next I removed all rust from the rear axle housing cover and nearby areas, then removed the fill plug and then drained the gear oil. Next I cleaned the area with soap and then burned off all organics materials with a torch and then repeated the cleaning process 2x. Once completed with cleaning, I replaced the drain plug, using new washers. I then coating the rear axle cover with JB Weld and allow the epoxy to cure for 24 hours. Finally, refilled the gear box with new oil. Replaced the fill plug, with new washers. It has been a couple of months now and it has held up. I will definitely inspect the breather plug yearly to make sure it is not plugged. I may even extend breather plug using tubing. I have photos I will try to post.

differential and frame rust issues
 

Last year I had to spend $2400 to replace rear end differential in 2000 4Runner. It had rusted through and oil dripping on ground. This year the frame was so rusted in one spot that it would not pass inspection. This time it cost me $1900. Has there been a recall on any of this stuff???

PO'd in Maine

I did the Epoxy route and so far so good, I brought it to my mechanic and he drained the diff oil and sanded down the rusted part......applied marine grade epoxy and let it cure for at least 24hrs.....then applied paint over it....cost 100bucks......I was not willing to spend thousands on a 12yrold truck..........if it happens again....I will have him do the weld route.....it sucks but it is what it is.

YOU HAVE TO HAVE A WORKING BREATHER !!

None of the repars will work if you don't have a working breather. Even the small pressure increase from warm up will push oil right through quickly. As far as welding goes, don't bother. Even if you can successfully weld this now very thin metal, you will just discover new holes that were almost leaking already. I wasted countless hours with this two years ago (see page 2) and all fixes failed, untill I made the breather start doing it's job. After fixing the breather, all that was needed to stop the leaking was a little RTV squished into the well cleaned holes. Cost for final solution was 2 cents worth of RTV, a little carb cleaner and some elbow grease. Sorry I couldn't have help some of you earlier, but I did post the breather issue back on page 2. Oh and if anybody cares my frame is rotted really bad too. Haven't come up with a cheap solution for that yet, so feel free to add your 2 cents worth.

my
 

Hello!!!!!!! Good post!!!!!!!!!

Hi Mark - Had the same problem. Cleaned the differental, removed rust and used JB COld Weld.Has held for over one year. Got the idea from previous post. Worked great and better than the alternative of installing a new or used rear axle.

my
 

Hello!!!!!! Good post!!!!!!