The transfer case is dead! Long live the transfer case!!!!

Alas, our fine Toyota 4runners are machines made by man…even if they were hewn from hand-collected and smelted ore by 10th generation Katana sword smiths.

My transfer case met it’s demise at the end of a dirt road, as shifted from 4hi to 2wd. I tried to slide the lever forward at around 10mph before entering a paved road. It felt like a “gummy” shift, like you feel when you try shifting it with the wheel slightly turned. Except I was straight. It slid into 2wd, but felt wrong. I tried a couple of times before the 4x light went off. After driving on pavement for about 20 miles, after entering another dirt road, I tried to shift into 4hi as usual, except and the stick very freely fell into 4hi with loud hard grinding. Tried it again at maybe 5mph, and again grinding so hard that I immediately aborted my shift. It would shift perfectly fine into 4hi (and oddly, with very smooth low resistance) when I stopped completey. It would drive in 4hi once engaged, and 4lo, without a problem. I cut my trip short and headed for home (about 150 miles away). Total mileage when it failed: 49,923 miles. No noises or problems on the way back.

Basically, I lost my ability to shift on the fly. My first thought was that I messed up my synchro. But I hoped maybe it was because it didn’t like the Royal Purple “synchro safe” gear oil I had put in about 14000 miles back.

The next day, I decided to drain the transfer case oil. Hoping for the best, but anticipating the worst, I cleaned up milk jug to catch the oil. About a second after I removed the drain plug, I heard something hit the bottom of the jug.

 

This is what fell out:




Also, the oil very clearly had brass colored synchro glitter in it.

 

I posted a picture of the part to my local group of guys on Tacomaworld, since I knew that at least one of them had experience taking apart the tacoma case when making a crawl box kit. My answer came back in 5 minutes…the part is one of the of three “keys” that help radially locate the synchro ring.

Thankfully, my tacoma buddy sent along a pdf of his crawl box manual that showed how the piece fit, which basically confirmed it for me…that piece probably had friends floating around in there, just waiting to get caught in a gear or the chain and lock everything up. …the transfer case is dead.

Next was deciding if I took this into a dealer for a warranty claim, or if I just bite the bullet, buy a new TC for $3k, and try to change the TC myself, with the moral support of the local group I hang out with.

Two reasons made me even consider changing out my own TC. I hate dealers. Apologies to any good guys working at a dealer, I know they exist..it’s not you, it’s the system…well, and I guess the high percentage of scummy people that work there lol). All I could imagine is them taking the vehicle, denying me warranty because it’s been used off road (and I didn’t have toyota liquid gold in the TC). All they would do is simply deny and put the ball in my court to prove that I didn’t cause it. And even if I “won” that fight, it would mean the 4runner would sit in a dealer for who knows how long to get fixed, and I’d probably lose the rest of my summer and planned trips.

The other reason I considered changing out the TC myself, is that I’m always harping about how simple 4runners are to work on…maybe it’s time to put my money where my mouth is, and experience that DIY high after finishing a big job you thought you’d never do. I’m not getting any younger, and this kind of adventure opportunity doesn’t happen every day

Turns out, the same buddy that identifies the AWOL piece that fell out of my TC, also mentioned he had been looking to buy a manual shift TC at a local salvage yard from an 18 OR, with 55k miles on it. For 270 bucks! He allowed me to call dibs on it, and I picked it up the next day! Sweet!!! The decision’s been made.

 

RIP.

Are you anywhere near Chicago, Illinois (The Car Care Nut mechanic...) If you're not familiar, he does repairs and postmortem reports on his channel.

I do remember, back in my Subaru owning days, that all the tires had to be the same size, same level of wear, same tire pressure or it would throw things off.

Own an extended warranty?

 

Yeow!

Fixable, or new TC needed?

 

I'm assuming you'll be taking to the dealer for warranty replacement. Hopefully they wont have a reason why they think it's your fault. Tcase is a rare failure for sure.

 

Yeah, caught that immediately after I posted.

 

.

 

Any guesses on what dealer can say on mods that contributed to failure?

 

Nope! To be continued below…

 

https://autoparts.springhilltoyota....ear_code=2021:8670&search_query=Transfer+case

 

We had our rear diff go out in the middle of nowhere (25 miles North of Alturas, CA). Real nightmare (as I related elsewhere). Turn out a service tech had not replaced the drain plug after servicing. $7400 in repairs! (OUCH!!) Valvoline picked up the tab!

 

Would a salvage t case be an option? I am always leery never knowing what the use of maintenance history was. This is a rare failure point from my experience.

 

Sorry to hear but yeah warranty it out. In before someone blames the fluid you used.

 

So this all happened back on July 24th. I was in the middle of finishing my roof rack, and I was getting ready to pick up my new heavy-ass skid plate system that I had to prep and prime before a wheeling trip with @Thatbassguy and the other local TW buds I was talking about. I had lots of work on the table, and wasn’t expecting a TC replacement in the middle of all this, but I could make it work.

Over the course of the next few days, I inspected and prepped my “new” transfer case for install, freed the driveshafts, and prepped to take down the broken transfer case. Usually, I would research a job like this like a surgeon before surgery, but it looked so simple, I just jumped in.

I decided to buy a transmission jack at harbor freight to help lower the TC, but ended up pulling it off onto my chest and rolling it over to the ground after I found the jack just got in my way. The same in reverse to put it back on.

The reason the jack got in my way is because I took a shortcut that seemed smart at the time…I didn’t remove the trnsmission mount…. I wanted to avoid that so I didnt need to hold up the trans with a jack and take up more space.

The problem was that the transmission mount gets in the way of ONE bolt, which meant I couldn’t back it out completely. No problem I thought, I’ll just back out the bolt a bit, slide the TC down a bit, back out some more, etc until the bolt came out. Much hilarity ensued…
Eventually, I got the TC mounted, and buttoned down.

You can see the wrench on the bolt that interferes with the trans mount below:




Here is the new case (top), with broken TC (below)




And here she is, 500 miles later, with no leaks, and new armor painted and installed!

Bonus triumphant rock bro pose included!

 

Nice job? Any guesses what caused it to fail? 1 in a million failure?

 

The salvage TC I got seemed pretty good. For the price I got it, if it didn’t look good, I’d sell it down the line and just buy a new one. However, besides having to chase out the threads on the bolt holes, and cleaning up/polishing a couple of spots of rust on the input shaft, it looked and shifted fine. Thankfully, the salvage yard left the shifter on, so I didn’t need to worry about water intrusion or bird shit inside the case lol. Also thankfully, it hadn’t been drained! When I drained it, the oil looked and smelled like fresh Toyota gold! No evidence of water or particles!
And as a bonus, the previous owner had a Teton workshop shifter nob!!! Score!!!

 

What fluid did you choose for the salvage t case?

 

My experience with the manual shift goes like this: I bought a 20 OR, a former rental car, as a Toyota certified used vehicle. I did the monthly gear shifts and got very used to the feel, occasionally used the 4-H on a gravel road outside of my monthly testing.

Dealership bought back my car after a year due to a whole bunch of issues and I get my 23 ORP... The shifting is exponentially better. I have no doubt that somebody chewed up crap shifting it incorrectly.

I would be leery of getting a salvage yard one unless there was some way to check the Toyota ownership records (because Carfax sucks and will miscategorize things as work done when noted as declined by the customer on the Toyota website)

Maybe if the salvage yard has some sort of return policy where the item can be disassembled and inspected before installation to make sure it wasn't abused...

 

I was quite impressed that you were able to roll this into your load of projects before the Tigerton trip!

As far as I could tell, the new T-case performed flawlessly.

What are your plans with the old one? Are you thinking about pulling it apart and repairing it?

 

Yes. They would have blamed the 285/70 K02s I had mounted about 300 miles before failure, they would have blamed the fact I had Royal Purple Maxgear 75w90 in the box for 14kish miles, they would have blamed it the fact it was used off road. Hell, they’d probably say I’m not supposed to use 4lo because that’s only for “experts”or “severe emergencies” or something stupid like that.

Seriously though, all these reasons, as highly unlikely they are to have caused the failure of whatever happened with the synchros, are probably enough for the dealer to refuse warranty. They aren’t going to actually know or find out why it failed. That takes too much work.

Based on the part that came out, the chunky nature of the synchro glitter, and the crawl box install instructions showing how the synchro and synchro retention thingies (one which fell out), I suspect the synchro ring broke. I can’t imagine how the synchro would fail due to my modifications. Tires and off roading would stress the chain and gears in the TC, not the synchro.

In my completely novice opinion, I would think the synchro only sees stress when shifting, and only for the briefest time it takes to spin up the front driveshaft. I really don’t know if maybe I shifted too much at higher speeds (40-45mph) and wore out the ring? Because I would do that occasionally on straight roads to exercise the system. Maybe I should have shifted at lower speeds instead? Or was it because of the occassional gummy shift when I had a little tension on the system? I don’t know, but I would like to find out.

Interestingly, I couldn’t find anything online with others having this kind of failure. Zero! Even on other similar Toyota transfer cases.

Their’s a good chance I’ll eventually tear into the broken TC to try and figure it out.

 

The TC has a 6 mo warranty. No way, even with enough time and knowledge, that I would disassemble a salvage TC to make sure it’s right. Too much work and risk.

My thoughts are, I did a visual inspection, ensured it shifted mechanically in an expected manner, and inspected the drained oil, all on the bench before installing. It all looked good.

Currently, I’ve put about 1600 miles on it since install with no problems. Hopefully, I’ll have luck with it for the duration. But if it blows up, I’ll just buy a brand new one from a toyota parts dealer website. If I have time, I’ll put it in myself, or pay a transmission shop the labor to install it.

 

I’m kind of hoping we can have a “failure mode reveal” party and we can all take it apart over beers


That actually sounds like it would be fun! Supr4lo made it sound like a repair probably won’t be expensive in terms of the parts involved. Just need the time and concentration to figure out how to get it all put together right. But I think it’s totally doable, especially with those manuals he sent me.

I’m kinda hoping that posting this tale will catch somebody’s eye that has seen this kind of failure before. I doubt it was due to how I operated it, but even if it was, it would be nice to know so I can avoid it happening again.

I still don’t think it makes sense that a few hundred miles on 285/70s, or the royal purple in the TC caused it, mostly because you’d think TCs would be failing all over the place. And regarding off-roading, yeah…you already know how I tip-toe myself through obstacles. I’ve hit individual potholes that cause way more stress than an entire weekend of trial riding the way I drive off road.

But maybe in the end it was just a material defect that led to failure.

Taking it apart might give me clues, but not necessarily tell me what led to the failure. But hearing of any other similar failures might help solve the mystery in the end.

 

It wasn’t the fluid…………………probably.

But, you know what? I’m not a betting man lol.




I find it hilarious this cost me fully 1/3rd the cost of the replacement transfer case

 

Sucks you had to eat the cost of a new one, but understand why you just replaced it anyway. I'd roll up to the dealership with the tcase in the back and see if they're willing to give you a new one. Just say you weren't in a place to get to a dealer and had a used one put on temporarily. If they tell you no you're in the same place as you are now. Who knows, they might say yes.

 

@McSpazatron Amazing that you were able to get this done and wrenched on the rig yourself! Great updates also.

 

Nice work!

 

Hmmm, that’s actually a great idea. All the toyota dealers around me have been a pain, but I’ve never tried the dealer where
i bought it…. It’s 100miles away, but maybe the next time I’m headed that way I’ll take it along to see what they say.

 

When our rear diff failed, the Toyota dealer shopped around and found a 4Runner with LESS miles that had been in a front-end crash. Pricey but 1/2 the cost of a new original replacement.

My old pre-Tacoma p/u (327K miles) had several computer chips replaced with ones from junk yards. Mechanic said we could buy-and-try 4 or 5 for the price of a new one!

 

An odyssey worthy of the heroes of the ancients!

I once participated in the removal of a broken transfer case chain. The transfer case was removed on the trail and disassembled on top of a flat rock. The chain was removed and the owner drove home with rear wheel drive only.