UPDATE: Alright so after speaking with the tech that looked at my vehicle. Software is not throwing any codes whatsoever. T-case and diffs = fine, drive shafts= fine. torque converter= no codes. The tech tells me because all of those things check out and the computer isn’t throwing a code the FSM recommends the only recourse is full replacement. On top of that there is only ONE factory transmission available and it isn’t even a rebuild it’s used with 68,000 miles on it (likely off of a wreck. Quote for parts and labor on that is north of $3k.

I’m seriously against the fact that this transmission is completely dead. I am leaning towards having a professional transmission technician try to diagnose the problem and see if maybe just a simple tranny drop and replacement of a few components is more cost effective than a full replacement. I talked with the guy who sold it to me and he has assured me that no overloaded payload or towing occurred while he had it and I truly don’t think he has a reason to lie considering I bought it so long ago.

If you want stats as it sits with all mods I am

1,110 lbs over curb weight
Payload capacity is 1700lbs
Enough to kill a tranny? I’d tend to think no.

I would almost consider the dealership option if it was AT LEAST a rebuild even though it’d be a little more expensive it would come with 2year 100k warranty.

I wish I could help you but automatics are vodoo magic to me. I hate that this is the first Auto vehicle my family has owned.


I'm assuming reverse is also dead in the water? Solenoid in trans? Speed sensor on trans? I'm surprised there are no codes. What's that fluid look like?

Yeah no power to wheels in any gear. Fluid is clean as a whistle and the fluid that was exchanged was worn at normal levels without indications of major issues (I.e. metal chunks)

I am not a transmission expert by any means, but I do drive Ram trucks which are known for their poor automatic trans reliability, so I've gone a few rounds with this type of issue. I have a question or two. I may have missed the answers in previous posts, so I apologize for repetition.

Can you put the t-case in 4HI or 4LO and achieve movement?

If yes, then I would put money on a broken t-case output shaft but I'm doubtful on any movement at all.

If no, then I would put money on a broken transmission input shaft.

Since you said that putting it in P keeps it from rolling, I think that eliminates the output shaft since the parking bands keep the trans from rotating. If the output shaft were broken it would most likely still be able to roll. That would also eliminate the question of whether you can move it in essentially front wheel drive.

I don't believe you would see any codes because the torque converter is still turning with the engine thus supplying pressure to the solenoids etc. so they're all happy, things just aren't spinning. What I don't know is if these rigs are equipped with sensors that detect trans slippage. That would be the only thing that I could see would throw a code. I imagine the trans is all electronic so without it spinning and sending signals to the computer telling it to upshift it just sits there feeling like it's in N.

Again, not a trans expert and even less versed on the transmissions in Toyotas. The broken shaft only makes sense to me due to experience with HD trucks and hauling weight all the time but it's more often due to adding HP/torque before addressing potential weak spots. Input shafts are a very common failure which is why I put a billet one on my truck when I had to get it rebuilt last year. I'm also making about 600hp and probably closing in on 1000lb/ft of torque. Since you're kitted out, that weight puts added stress on the trans and over time could result in this type of breakage. The sound you heard may have been the input shaft giving up the ghost.

I would definitely seek out a reputable transmission service shop and see what they have to say. I know you're already in it with the dealership but I have a total lack of faith in dealerships of any kind and avoid them for everything except for warranty/recall work.

There is the very real possibility that I'm way out to lunch in which case I've just wasted a bunch of your time...so I apologize for that in advance.

No that’s a good theory. I will definitely put in the list I present to the transmission tech. BLUF: Toyota transmission failures are so rare nowadays they do not have trans techs at the dealer anymore unlike Nissan or ford for example. Really the tech I talked to was a very knowledgeable guy and really sincere and heavily insinuated that this is just “what he has to tell me” but I was picking up the vibe that a more qualified transmission specialist may be able to give me a better diag.

I would call some "well known" transmission companies for an opinion, such as Import Performance Transmissions to start with. I don't have a number but Google them. Search the forum for transmission problems and see if any other companies mentioned.

I would also go to a transmission shop. It's hard to find really good ones. I'd consider calljng around first and ask if they have experience with Toyota automatics. A lot of trans rebuild shops have never touched one. The failure rates are really low that used ones are usually cheap because there's no demand and they are so infrequently rebuilt that many shops simply haven't ever had a chance to work on them. I know locally most will sub out toyota transmissions to some national specialty place.

I don't think 1k lbs over weight would phase it at all. It's only got a little v6 pushing it. The same transmission was used behind V8's for a lot of years with a lot more torque - including supercharged v8s. And it holds up just fine behind supercharged v8 torque. Could you abuse it to the point of failure? Probably, but it's really hard to do.

The idea of a shaft failure seems like a good thought, but my issue there is that it's a v6. It shouldn't have enough torque to come anywhere close to snapping a shaft in that transmission. If you have shop space and tools, I'd start by checking trans fluid level one more time. Then drop the transmission pan and just see what's inside. Maybe the oil pickup is clogged or the oil pickup tube somehow came off. Visually check all of the electronic connections. Maybe even pull them apart and put back together. And double check the cable linkage to the shifter to make absolutely sure you're not somehow disconnected or loose and it's stuck in neutral.

I would also double check and make sure that the transmission in park is locking up the rear tires firmly. It might be in neutral and somehow the transfer engagement clutch is just friction closed and not engaging the teeth. Basically put in park and try to push it with maybe 2 people and see what happens.

If you do need to replace - I'd personally prefer a low mile used over a rebuilt. I've had so many bad rebuilt engines and transmissions that if it isn't an OEM rebuild or someone very experienced like an Aisin specialty shop, I'd rather have a used one. I think the going rate is around $1k for the used takeout. For example: here's one with under 60k miles for under $1k. Used 2016 TOYOTA 4 RUNNER TRANSMISSION - OEM 3200004010 - Benzeen Auto Parts No affiliation, but I order from them periodically and have had good experiences so far. The reason is that they always have a picture or set of photos of the actual vehicle it came out of so you can see the damage and make sure it isn't likely to damage the parts you want.

Good luck. Hope it's something easy and cheap!

I'm sure he was sincere, but it's worth noting that they'd probably get shafted on diagnostic time so it's like 1000% easier and profit effective to just hot-swap a transmission in.

That being said, an actual transmission shop might have more insight.

A Google search "no gears toyota 750 automatic transmission" and "no forward or reverse toyota 750 automatic transmission" has some info. Unusual failure on first item, little new info on second item, third item applies to any transmission. There are other hits, but I didn't review them.

A750F Failure | IH8MUD Forum
Tranny gone | Toyota Tundra Forums
https://www.youtube.com/watch?v=4lBwCklGa7s

I am in now way a transmission expert, but here is my input on it as I had a similar issue in the past and why I do not touch transmissions unless I absolutely know the history of them.

First question: Before you did it, do you know when the fluid was last changed and was it done regularly? By regularly, I mean every 50k miles or so..

Here is why. I had a GMC truck that had this exact issue. I know not a Toyota, but the 4L60E Gm Automatic is an incredibly reliable and stout transmission. It had 90k miles on it, so I thought I would drop the pan and do a fluid change. 500 trouble free and better shifting miles later I thought I did the truck a favor. Shortly after, I lost second gear. Shortly after, no forward go at all. The trans shop told me the fluid was never changed and I changed the environment in the transmission and it would have been better to just leave it at that point. The trans is used to the old fluid. A $2500 mistake to rebuild the trans. Ouch

There is always debate to do a flush/exchange/etc. and I always err on the side of no unless I know it's been done consistently.

This is my thought as to what happened, but obviously you won't know unless it's pulled apart.

Ask around for who the most reliable transmission shop is (Nextdoor app is good for that stuff) and take it there for an opinion. Even the independent Toyota shop I trust the most simply raise their hands and back away at the mere mention of the dark arts of automatic transmission internals. Even if you do need a whole new one a transmission shop should be able to source it better probably.

I have heard this from many people not to touch it at high miles if not done before, something about material being suspended in the fluid after so long and holding things together from what I remember. I couldn't resist the urge to do a drain and fill on mine at well over 100k. I don't think it was done by previous owner, would have to check service history. The return line thing sketched me out a bit so just drain and fill every so often with Toyota fluid. I did drop the pan and clean the magnets when I first got it, and replaced the strainer (old one seemed fine so basically a waste of time and money).

Who knows what half-baked thingd the previous owner might have done with a trailer. Seems quite unusual for it to fail like this.

I have trouble believing it's trans input shaft unless you've been drag racing! Has to be something less disastrous, like one of the pins on the electrical connector on side of trans even though no code. Can't believe the trans would just break and quit with no major event signaling it, i.e. loud noise, instantaneous grind and stop, etc.

BTW a good vid for anyone who might be throwing sideways glances at their high miles transmission from reading this thread:

https://www.youtube.com/watch?v=iJjA-y35HQM

https://www.youtube.com/watch?v=GfxBMef-8hg

They seem pretty keen down there in Australia on valve body upgrades for towing too.

This makes me nervous as I'm considering a trans flush and fill at the dealership for like $210. I know you are screaming, "DON'T DO IT!"

My regular guy doesn't mess with sealed Toyota transmissions.
144,000 miles. Going in for the airbag recall. Shifts normally and I drive granny easy normally, no 4-wheeling, no towing, flat roads here in Wilmington NC.

For your trans, there's a bunch of youtube videos to get some different perspectives.

Snapped axle? But I'd think it would make all kinds of grinding noises.
Shift solenoid?
Stripped input or output shaft gears (probably the wrong terminology).
Probably not a shift linkage bushing, my wife's GM had that, you couldn't shift at all. $5 flimsy plastic part and a lot of figuring and fiddling and we were back on the road.