Transmission has stopped engaging Overdrive?

[DriftwoodDaddy]

Hi all, obligatory "first post". I've had my 06 V6 4x4 Limited for a year and a half now. It's been great, I love the truck and it's easy to work on. It's not without issues, but I'm fine with that on a 15 year old vehicle and part of the appeal to me is that it's easier to learn on and fix up than a newer car!

Anyway, it has ~110k miles on it now and I've noticed in the past month or so that it's not getting into OD on the highway. Every other weekend I drive approximately 3 hours on Rt95 but lately it's all been in 4th gear at like 3200rpm. I understand this isn't terrible to do, but I'm worried about the cause of this issue. First time I noticed it, I pulled off and restarted the truck, and then OD worked for the rest of the drive. Since then though, no OD. I've searched around but haven't found anything definitive, but here's what I've learned:

• The tranny won't engage OD unless the engine and/or ATF temp sensors register a high enough temperature
• A faulty solenoid could be preventing the OD gear from engaging
• The AT fluid in my 06 is "lifetime" and the transmission is sealed, but possibly low or old fluid could cause this issue
• I don't think it's a "transmission" issue as much as an electrical or fluid issue

So, I'm trying to start with the easy and work to the hardest in troubleshooting. The V6 doesn't have dedicated "4" and "D" shift notches, so it's in the right gear and I'm not accidentally bumping it out of OD. The weather is warm and I'm driving for hours, so it's not a legitimate cold tranny issue. All other gears are working fine, the transmission shifts smoothly, and it doesn't hunt for gears.

First, can anyone tell me if I'm on the right track?!?

Second, can anyone confirm which temp sensor(s) the computer uses to determine when OD can engage? I'm thinking this would be the easiest fix. My engine temp gauge still works so I'm assuming that sensor is fine? I would be able to replace sensors on my own if anyone can share part numbers and a brief writeup.

Can anyone comment on the "lifetime" AT fluid? Would that be an issue at 110k miles? If a tranny fluid swap is known to help this issue, it might be worth taking it to a dealer for that; I don't think I would attempt that work on my own.

Moving on to the solenoids... I'm pretty hazy about the inner workings of a transmission so I'm not gonna pretend to know. Would a sticking solenoid prevent a single gear from engaging like I've described? Is it possible/worth it to check on or replace a solenoid?

I do my own oil changes and installed my lift on my own but I'm no mechanic. I do have access to a shop though so with info and a plan I can do simple repairs.

Any help is appreciated!

 

[Piggity]

Hi all, obligatory "first post". I've had my 06 V6 4x4 Limited for a year and a half now. It's been great, I love the truck and it's easy to work on. It's not without issues, but I'm fine with that on a 15 year old vehicle and part of the appeal to me is that it's easier to learn on and fix up than a newer car!

Anyway, it has ~110k miles on it now and I've noticed in the past month or so that it's not getting into OD on the highway. Every other weekend I drive approximately 3 hours on Rt95 but lately it's all been in 4th gear at like 3200rpm. I understand this isn't terrible to do, but I'm worried about the cause of this issue. First time I noticed it, I pulled off and restarted the truck, and then OD worked for the rest of the drive. Since then though, no OD. I've searched around but haven't found anything definitive, but here's what I've learned:

• The tranny won't engage OD unless the engine and/or ATF temp sensors register a high enough temperature
• A faulty solenoid could be preventing the OD gear from engaging
• The AT fluid in my 06 is "lifetime" and the transmission is sealed, but possibly low or old fluid could cause this issue
• I don't think it's a "transmission" issue as much as an electrical or fluid issue

So, I'm trying to start with the easy and work to the hardest in troubleshooting. The V6 doesn't have dedicated "4" and "D" shift notches, so it's in the right gear and I'm not accidentally bumping it out of OD. The weather is warm and I'm driving for hours, so it's not a legitimate cold tranny issue. All other gears are working fine, the transmission shifts smoothly, and it doesn't hunt for gears.

First, can anyone tell me if I'm on the right track?!?

Second, can anyone confirm which temp sensor(s) the computer uses to determine when OD can engage? I'm thinking this would be the easiest fix. My engine temp gauge still works so I'm assuming that sensor is fine? I would be able to replace sensors on my own if anyone can share part numbers and a brief writeup.

Can anyone comment on the "lifetime" AT fluid? Would that be an issue at 110k miles? If a tranny fluid swap is known to help this issue, it might be worth taking it to a dealer for that; I don't think I would attempt that work on my own.

Moving on to the solenoids... I'm pretty hazy about the inner workings of a transmission so I'm not gonna pretend to know. Would a sticking solenoid prevent a single gear from engaging like I've described? Is it possible/worth it to check on or replace a solenoid?

I do my own oil changes and installed my lift on my own but I'm no mechanic. I do have access to a shop though so with info and a plan I can do simple repairs.

Any help is appreciated!

Start with changing the transmission fluid, I bet that's the problem. I have 380,000km on my 06' V6 and I've done it twice now (but I tow).

Toyota does say it is lifetime fluid but that's really not the case. If you tow or do any high performance driving, or even live in a hot area like CA or AZ I'd do it every 50k.

 

[firebirdguy]

first of all, the OD is not related to temperature, the trans should go into OD at the right speed & engine load regardless of if its -10f or 100f. so its not related to temps of the engine or trans/fluid.

the fluid is not lifetime, toyota recommends change at 100k miles or 60k if towed or abused, however, at 110k miles its should still be ok depending on its history. based on the symptoms you describe i dont think a fluid change will fix the OD issue unless its low, sounds like its solenoid/sensor related or possibly shifter/cable adjustment issues. best is to have a mechanic or trans shop look at it & test & diagnose further. also check for any codes that may be strored. but a fluid exchange is due so it cant hurt to try that first.

 

[DriftwoodDaddy]

first of all, the OD is not related to temperature, the trans should go into OD at the right speed & engine load regardless of if its -10f or 100f. so its not related to temps of the engine or trans/fluid.

This contradicts a lot of the info I've been seeing that the computer holds out on using OD until certain temp parameters are met, in an effort to reduce engine strain or reduce emissions or something.

It does sound like new fluid should be at the top of my list though, I didn't realize it has a 100k life. And I'll check for codes, I have a cheap code reader. Thanks!

 

[DriftwoodDaddy]

Start with changing the transmission fluid, I bet that's the problem. I have 380,000km on my 06' V6 and I've done it twice now (but I tow).

Toyota does say it is lifetime fluid but that's really not the case. If you tow or do any high performance driving, or even live in a hot area like CA or AZ I'd do it every 50k.

Yeah it looks like that should be my first change. I'm also going to check for any codes, it's not throwing any check engine or OD lights or anything but maybe there's a code stored. Thanks!

 

[triethylborane]

Moving on to the solenoids... I'm pretty hazy about the inner workings of a transmission so I'm not gonna pretend to know. Would a sticking solenoid prevent a single gear from engaging like I've described? Is it possible/worth it to check on or replace a solenoid?

Each gear has an individual solenoid, so yes, a single faulty solenoid can prevent a single gear from engaging. I dont know what the process is to do this on the Aisin unit in your 4runner, but Ive replaced solenoids on a ZF trans on my BMW xDrive wagon . . . some skill and problem solving required, though not an awful job. I too have a lift in my garage, which reduces a significant amount of brain damage.

I would check codes in the TCM, then ECT/TPS sensors, then look at fluid. It sounds like you are going to replace fluid, so might as well see if any of the other items are shot, then go on to the fluid. Maybe check and see if you can drop the valve body that holds the solenoids (or however it is on the Aisin) and if its easy/cheap, give it a go.

 

[Keros]

the fluid is not lifetime, toyota recommends change at 100k miles or 60k if towed or abused, however, at 110k miles its should still be ok depending on its history.

I wanted to double down on this. There's 75 mentions of the word "transmission" in the '08 4Runner owners manual (the earliest I had readily available, as far as I know, identical mechanical drivetrain in both V6 & V8, same transmission to both engines anyway).

There's no mention of the transmission being "sealed", lifetime, or non-serviceable.

The exact text is:

465AUTOMATIC TRANSMISSION
Fluid capacity, L (qt., Imp. qt.):
4.0LV6(1GR−FE) engine10.7 (11.3, 9.4)∗
4.7LV8(2UZ−FE) engine10.9 (11.5, 9.6)∗
∗: The fluid capacity is the quantity of ref-
erence. If replacement is necessary,contact
your Toyota dealer.
Fluid type:
Toyota Genuine ATF WS
Change automatic transmission fluid only
as necessary.
Generally, it is necessary to change
automatic transmission fluid only if your
vehicle is driven under one of the Special
Operating Conditions listed in your
“Scheduled Maintenance Guide” or
“Owner’s Manual Supplement”. When
changing the automatic transmission fluid,
use only “Toyota Genuine ATF WS” (ATF
JWS3324 or NWS9638) to aid in assuring
optimum transmission performance.
Notice: Using automatic transmission
fluid other than “Toyota Genuine ATF
WS” may cause deterioration in shift
quality, locking up of your transmission
accompanied by vibration, and ultimate-
ly damage the automatic transmission
of your vehicle.
Please contact your Toyota dealer for fur-
ther details.

We can agree that it is worded here to imply it doesn't need to be changed except under specific circumstances. However, it's not saying it never needs to be changed and/or should not be changed. And as firebirdguy pointed out, there's a service interval listed for transmission fluid in the maintenance guide.

See: Maintenance Schedule - Toyota Canada

I recall reading Toyota removed the dipstick because many vehicles were coming in for service due to overfilled transmissions. Having had a 3.4L 3rd gen with the 4sp, it was notoriously difficult to get the level exactly right while checking it with the dipstick. It's an understandable change to the fill/full port system on the A750x transmissions.

Anyway, almost every transmission thread talks about the sealed/non-serviceable fluid myth. I'd speculate to say the manual's terrible phrasing doesn't help to halt the myth... but it's certainly a service item that should not be ignored.

I'm sure someone's gonna roast this post by throwing down the TSRM's page about the transmission being sealed, haha. I don't have time to root around and find the page, but I'd like to know what the spec there is. It would be a terrible irony if the factory service manual said something that conflicts with Toyota's own service interval website.

 

[y=mx+b]

Hi all, obligatory "first post". I've had my 06 V6 4x4 Limited for a year and a half now. It's been great, I love the truck and it's easy to work on. It's not without issues, but I'm fine with that on a 15 year old vehicle and part of the appeal to me is that it's easier to learn on and fix up than a newer car!

Anyway, it has ~110k miles on it now and I've noticed in the past month or so that it's not getting into OD on the highway. Every other weekend I drive approximately 3 hours on Rt95 but lately it's all been in 4th gear at like 3200rpm. I understand this isn't terrible to do, but I'm worried about the cause of this issue. First time I noticed it, I pulled off and restarted the truck, and then OD worked for the rest of the drive. Since then though, no OD. I've searched around but haven't found anything definitive, but here's what I've learned:

• The tranny won't engage OD unless the engine and/or ATF temp sensors register a high enough temperature
• A faulty solenoid could be preventing the OD gear from engaging
• The AT fluid in my 06 is "lifetime" and the transmission is sealed, but possibly low or old fluid could cause this issue
• I don't think it's a "transmission" issue as much as an electrical or fluid issue

So, I'm trying to start with the easy and work to the hardest in troubleshooting. The V6 doesn't have dedicated "4" and "D" shift notches, so it's in the right gear and I'm not accidentally bumping it out of OD. The weather is warm and I'm driving for hours, so it's not a legitimate cold tranny issue. All other gears are working fine, the transmission shifts smoothly, and it doesn't hunt for gears.

First, can anyone tell me if I'm on the right track?!?

Second, can anyone confirm which temp sensor(s) the computer uses to determine when OD can engage? I'm thinking this would be the easiest fix. My engine temp gauge still works so I'm assuming that sensor is fine? I would be able to replace sensors on my own if anyone can share part numbers and a brief writeup.

Can anyone comment on the "lifetime" AT fluid? Would that be an issue at 110k miles? If a tranny fluid swap is known to help this issue, it might be worth taking it to a dealer for that; I don't think I would attempt that work on my own.

Moving on to the solenoids... I'm pretty hazy about the inner workings of a transmission so I'm not gonna pretend to know. Would a sticking solenoid prevent a single gear from engaging like I've described? Is it possible/worth it to check on or replace a solenoid?

I do my own oil changes and installed my lift on my own but I'm no mechanic. I do have access to a shop though so with info and a plan I can do simple repairs.

Any help is appreciated!

Do you have any CEL or codes? I was getting a p2759 for torque converter clutch solenoid, which resulted in it occasionally not being able to shift into overdrive and torque converter never achieving lockup. Transmissions are really out of my wheelhouse, so I took it to shop that diagnosed the issue to be the transmission external wiring harness connector. Apparently this connection on the transmission is really prone to corrosion, so they soldered in a new connection and that fixed it.

Also DriftwoodDaddy is a pretty good username lol. I live in Annapolis and commute to Baltimore for work, so I'll be on the lookout for a fellow old man tan 4runner on the road. If you're interested, theres another guy with a 4th gen in MD and we may go to AOAA or Rausch a few times this spring and summer

 

[AuSeeker]

Hi all, obligatory "first post". I've had my 06 V6 4x4 Limited for a year and a half now. It's been great, I love the truck and it's easy to work on. It's not without issues, but I'm fine with that on a 15 year old vehicle and part of the appeal to me is that it's easier to learn on and fix up than a newer car!

Anyway, it has ~110k miles on it now and I've noticed in the past month or so that it's not getting into OD on the highway. Every other weekend I drive approximately 3 hours on Rt95 but lately it's all been in 4th gear at like 3200rpm. I understand this isn't terrible to do, but I'm worried about the cause of this issue. First time I noticed it, I pulled off and restarted the truck, and then OD worked for the rest of the drive. Since then though, no OD. I've searched around but haven't found anything definitive, but here's what I've learned:

• The tranny won't engage OD unless the engine and/or ATF temp sensors register a high enough temperature
• A faulty solenoid could be preventing the OD gear from engaging
• The AT fluid in my 06 is "lifetime" and the transmission is sealed, but possibly low or old fluid could cause this issue
• I don't think it's a "transmission" issue as much as an electrical or fluid issue

So, I'm trying to start with the easy and work to the hardest in troubleshooting. The V6 doesn't have dedicated "4" and "D" shift notches, so it's in the right gear and I'm not accidentally bumping it out of OD. The weather is warm and I'm driving for hours, so it's not a legitimate cold tranny issue. All other gears are working fine, the transmission shifts smoothly, and it doesn't hunt for gears.

First, can anyone tell me if I'm on the right track?!?

Second, can anyone confirm which temp sensor(s) the computer uses to determine when OD can engage? I'm thinking this would be the easiest fix. My engine temp gauge still works so I'm assuming that sensor is fine? I would be able to replace sensors on my own if anyone can share part numbers and a brief writeup.

Can anyone comment on the "lifetime" AT fluid? Would that be an issue at 110k miles? If a tranny fluid swap is known to help this issue, it might be worth taking it to a dealer for that; I don't think I would attempt that work on my own.

Moving on to the solenoids... I'm pretty hazy about the inner workings of a transmission so I'm not gonna pretend to know. Would a sticking solenoid prevent a single gear from engaging like I've described? Is it possible/worth it to check on or replace a solenoid?

I do my own oil changes and installed my lift on my own but I'm no mechanic. I do have access to a shop though so with info and a plan I can do simple repairs.

Any help is appreciated!

Everyone has covered most of the bases on what could be causing your issue...but I must ask what gear is showing/lit up on your instrument cluster when it's not shifting into OD?

 

[DriftwoodDaddy]

I wanted to double down on this. There's 75 mentions of the word "transmission" in the '08 4Runner owners manual (the earliest I had readily available, as far as I know, identical mechanical drivetrain in both V6 & V8, same transmission to both engines anyway).

There's no mention of the transmission being "sealed", lifetime, or non-serviceable.

This is good info and supports what I've been hearing. Thanks for sharing, I'll bump up "ATF change" to my first order of business!

 

[DriftwoodDaddy]

Do you have any CEL or codes? I was getting a p2759 for torque converter clutch solenoid, which resulted in it occasionally not being able to shift into overdrive and torque converter never achieving lockup. Transmissions are really out of my wheelhouse, so I took it to shop that diagnosed the issue to be the transmission external wiring harness connector. Apparently this connection on the transmission is really prone to corrosion, so they soldered in a new connection and that fixed it.

Also DriftwoodDaddy is a pretty good username lol. I live in Annapolis and commute to Baltimore for work, so I'll be on the lookout for a fellow old man tan 4runner on the road. If you're interested, theres another guy with a 4th gen in MD and we may go to AOAA or Rausch a few times this spring and summer

No CEL, I'll run my cheapo OBD scanner tomorrow to see if it's throwing any codes. It's looking more and more like a job for a transmission shop, either to change the fluid (I don't feel like dealing with that...) or check the connections and try to diagnose the issue.

Thanks for chiming in! I've seen your name all over this forum, cool to find out you're local. I actually commute the opposite way, BalCo to AACo, but in a work truck. If you know a good place to grab some AT tires around here (255/70r18?) let me know! Then maybe I'll be able to tackle Rausch...

 

[firebirdguy]

This contradicts a lot of the info I've been seeing that the computer holds out on using OD until certain temp parameters are met, in an effort to reduce engine strain or reduce emissions or something.

It does sound like new fluid should be at the top of my list though, I didn't realize it has a 100k life. And I'll check for codes, I have a cheap code reader. Thanks!

curious where you are seeing this info, can you post a link? i live in the midwest & winter temps are regularly in single digits & can be below zero for weeks straight... every single time i drive my 08 4runner it will shift to OD when the speed & engine load call for it, same for previous vehicles ive owned or current ones with OD, they all go into OD when necessary. & most my drives have me hitting 40+mph within minutes & the engine temp gauge has barely moved. OD is not or at least should not be temp related.

 

[DriftwoodDaddy]

curious where you are seeing this info, can you post a link? i live in the midwest & winter temps are regularly in single digits & can be below zero for weeks straight... every single time i drive my 08 4runner it will shift to OD when the speed & engine load call for it, same for previous vehicles ive owned or current ones with OD, they all go into OD when necessary. & most my drives have me hitting 40+mph within minutes & the engine temp gauge has barely moved. OD is not or at least should not be temp related.

I found a lot of references to it while searching through this forum, it seemed to be accepted as accurate. Something about allowing the fluid to warm up enough to attain maximum performance/efficiency. I have no problem being wrong though! But would make sense to me.

That being said!! I think you've actually solved my case. While looking for threads to link for you, I stumbled across your thread asking about "4 vs D" on the shift gate...I think it turns out I'm just a massive idiot and never realized that there are, in fact, 2 individual shift positions there. I'll double check when I get home, but I'm suddenly feeling relieved and embarrassed! I have definitely been using the "4" position recently, I thought that's what I've always done but maybe not.

 

[DriftwoodDaddy]

Everyone has covered most of the bases on what could be causing your issue...but I must ask what gear is showing/lit up on your instrument cluster when it's not shifting into OD?

I'm an idiot. I've been putting it into 4 instead of D. I did not realize it's two individual positions on the shifter! After a year and a half....

Thanks for helping me come to this realization!

 

[DriftwoodDaddy]

Alright everyone, crisis averted. Turns out I am a dummy and never realized that "4" and "D" are individual shift positions... the labels are right beside each other so I had just assumed it was "4 with OD" not "4 and 4 with OD". I feel dumb but am glad there's nothing wrong with my truck!

I'll also still plan on doing an AT fluid replacement at some point, but I need new tires first...

Thanks for all the detailed replies and the good info.

 

[firebirdguy]

I'm an idiot. I've been putting it into 4 instead of D. I did not realize it's two individual positions on the shifter! After a year and a half....

Thanks for helping me come to this realization!

hey thats awesome you realized that & there isnt anything wrong with the trans. glad you did some more checking & testing & didnt pay someone to look at it or buy an additive that wasnt needed.

so its shifting into OD now? & when driving at highway speeds its not at the high rpm you mentioned? if so, sounds like the trans is working as it should, take it out when cold & get up to 40mph or so on a flat road & it should go right into OD like i was saying, regardless of temp. the manual actually says to leave it in OD all the time for normal driving unless towing or climbing hills etc. it should also kind of default to that position when pulling down from park, ive always had to manually push it to the left for 4 gear.

depending on mileage i would still do a fluid change or at least drain a small amount to look at it, if its dark & not bright red might be a good idea to change it. use whatever brand of CORRECT rated ATF you prefer. theres good write ups on here for full fluid exchange or can do 3-4 pan drain & fills.

glad the trans aint broken :thumb3:

 

[AuSeeker]

I'm an idiot. I've been putting it into 4 instead of D. I did not realize it's two individual positions on the shifter! After a year and a half....

Thanks for helping me come to this realization!

Alright everyone, crisis averted. Turns out I am a dummy and never realized that "4" and "D" are individual shift positions... the labels are right beside each other so I had just assumed it was "4 with OD" not "4 and 4 with OD". I feel dumb but am glad there's nothing wrong with my truck!

I'll also still plan on doing an AT fluid replacement at some point, but I need new tires first...

Thanks for all the detailed replies and the good info.

Awesome, glad my question helped you to realize the issue!

Don't feel to bad about it though, the reason I ask that question is because for the first week after I bought my T4R I drove it in 4th until I realized I was pulling the shifter towards me as I was shifting from park to "D" and thusly I was pulling the shifter into 4th every time, it's not hard to do when you're not used to the gated shifter since "D" and "4th" are side by side and doesn't take too much force to pull it left into 4th .

Definitely change the tranny fluid as soon as you can.

 

[Keros]

Alright everyone, crisis averted. Turns out I am a dummy and never realized that "4" and "D" are individual shift positions... the labels are right beside each other so I had just assumed it was "4 with OD" not "4 and 4 with OD". I feel dumb but am glad there's nothing wrong with my truck!

I'll also still plan on doing an AT fluid replacement at some point, but I need new tires first...

Thanks for all the detailed replies and the good info.

I'm relieved to hear the problem was between the steering wheel and seat, lol!

Yeah, many years ago, I was asking for help about a fogging problem on my 3rd gen, and didn't realize what the defrost symbol on the HVAC looked like... they explained it to me using very small words, haha. But, the fix was free, so it's all good.

No worries about driving the truck around in 4th (direct drive 1:1)... just rev's the engine higher.

Glad to hear everything's okay!

 

[Montego Murph]

Another vote for the "don't be too hard on yourself" camp. When we first bought the 03, my sister drove it somewhere in the winter and thought the "4" position was for 4 wheel drive.

 

[importman]

Awesome, glad my question helped you to realize the issue!

Don't feel to bad about it though, the reason I ask that question is because for the first week after I bought my T4R I drove it in 4th until I realized I was pulling the shifter towards me as I was shifting from park to "D" and thusly I was pulling the shifter into 4th every time, it's not hard to do when you're not used to the gated shifter since "D" and "4th" are side by side and doesn't take too much force to pull it left into 4th .

Definitely change the tranny fluid as soon as you can.

I have to avoid the tendency to pull the shifter towards me too. When I got my runner it had the binding shifter issue and with me messing with it I got the floppy shifter syndrome. I took it apart and "fixed" it but the detents aren't nearly as firm as they originally were. So I consciously avoid moving the shifter when driving, unless I need to downshift etc.