Transmission- 5 Speed automatic write up with pics for second gen 4 liter trucks

See posts 197-206 in this thread for reference

2005 Sequoia SR5 4x4, now at 272K miles


P1441 and P1444 codes cleared for good in October 2018 at 267K miles.
Throttle body & MAF sensor cleaned in January 2019 at 269K miles (some doubt about work quality).
New NGK Iridium IX plugs installed in January 2019 at 269K miles (old iridium plugs weren't terrible).
Fresh Mobil 1 High Mileage oil and new Pure One high mileage filter in January 2019 at 269K miles.
AC recharge & dye test in June 2019 at 272K miles (to replace refrigerant evacuated at Toyota dealership).
Have a new OEM PCV in hand, I just keep forgetting to put it in.

The throttle body & MAF sensor cleaning, new spark plugs, and fresh Mobil 1 oil had no impact on performance. Idle actually seemed slightly worse afterward. No improvement in fuel economy (stuck at 13.4 MPG city). I suspect that the new plugs aren't torqued to the correct 13 ft/lbs spec. Some of the old plugs weren't in very tight.

Until today, overall performance had been basically the same as noted in post #197--with the exception of the burning rubber and burning hair smell thing. Then this afternoon I went for a short test drive in city traffic with my newly recharged AC on. The symptoms described in post #197 are now more pronounced--I can occasionally feel a slight kick during downshifts. I'll be using the AC very sparingly from now on and will avoid "spirited" acceleration whenever possible.


During the time I've owned this vehicle I have visited no fewer than eleven local automotive shops, including two staffed by Toyota techs, and I have yet to find anyone around here who really knows and understands Toyota truck engines or transmissions and how they interact.
I have no choice but to continue the process of elimination until I finally find a local shop where they know Toyota trucks. I'll need a shot of confidence before I give anyone around here a costly project.

 

Only time I smelled burning rubber and hair at the same time was when I caught part of my mustache while smoking, and my buddy decided to roast his tires off on his Cummins right next to me while all my windows were down.

@Sawbill 's situation is rather odd.

 

I was just thinking about his burning smell .
When my air conditioning clutch burnt up , I had some burning smell in the cab . Perhaps some of the graphite. in the clutch could be the cause of the burnt hair smell Sawbill is explaining . It stands to reason that he finds the smell more noticeable now that its starting to warm up outside and the AC is running more often
He could always pull the fuses and relays to prevent the clutch from coming on and go for a test drive to see if the smell is gone .
Toyota,s run the ac anytime the heat is on to remove moisture in the cab as well as when the air conditioning is on .

 

If it's the AC clutch, it either needs reshimmed or replaced alltogether. That should have been noticed during his ac evac/recharge. It may be slipping just enough to create the burning smell but also provide adequate force to barely make the AC system work.

@Sawbill does your ac blow like the winds of Antarctica? Or just enough to keep the sweat off you?

 

P1441 and P1444 indicate a failure of the Secondary Air Injection System. See post #206. Drove less than 10 miles before applying the best known fix.

I've only encountered the strange burning smell when the transmission kicks into "passing gear" on the freeway. The first time was less than a month ago, and I don't recall if the AC has been on when it happens.

Previous owner had the AC "serviced" in May 2017 at 248K miles when the timing belt and water pump were replaced. He wasn't charged for the service. Last summer at 267K the AC was just cool enough the keep the sweat off. The Toyota guys had to evacuate the system when they pulled the engine out for my frame replacement.

The AC was recharged by a small neighborhood repair shop on June 10th. The system was almost completely empty. The low side schrader valve was leaking. After tightening the valve there were no more leaks. Set at 69F the AC is plenty cold now. The first occurrence of the smell was before the recharge and the last was afterward.

I decided to take back streets on my way home from work yesterday. With the AC off, I tried to keep a close eye on my tach as the transmission shifted. Part-throttle shifts seem to be about 200-300 RPM later now than they were a month ago. Up shifts and down shifts seem to be comparatively sloppy. I don't know if this is related to the strange smell in passing gear or not. I'll continue to monitor it.

Please keep the questions coming.

 

Great information on 4runner transmissions. My 2005 4runner V6 has 150,000 and tranny shifts perfect. Had the dealer change tranny fluid it at 100,000. Going to take it to the dealer at 170,000 miles.

I remember when I bought this car for $44,000 cash from the dealer in 2005 (in the Bahamas). I test drove a new Explorer the same day ($4000 less) which rode better, but I knew better.

My first Toyota couldn't have been better.

Bought my daughter a new Camry in 2015 when she got accepted into Florida State. Today that Camry has 36,000 miles runs great, and is in Denver where she got a job with one of world's biggest discount brokers. Don't have to worry about breakdowns and weeks waiting - and getting to work every day - with Toyota.

UPDATE: Went to visit daughter in Denver and see her workplace. Drove in her Camry throughout the "Rockies" for two days - saw a herd of 70 elk - and one elk alone 10 feet off the highway - where we "gauked" with an older couple. 4 cylinder Camry ran like a champ all the way to Aspin too. Gave the daughter $300 to change the oil and do the brakes (at 40,000 miles) because she's near the Rockies, and the dealer recommended it.

Saw no bear, so we're planning a trip back for Christmas.

Saw one fool's car crashed into guardrail because his brakes gave out coming down a "hill" in da Rockies! He was lucky they put a guardrail (about 30 feet of) where he ran off the road - 'cause it was a 1000 foot drop 1 foot further.

Kept telling my daughter to "slow down" coming down them "hills". Hundreds of tourists driving in the Rockies this time of year. Park people told us the road is closed down in the winter - with the snow - reopens in May!

Be careful!

Sawbill: 270,000 miles... why complain? I do my own plugs, but leave all else alone - including the MS. Starts like new, so why "fool" with anything. Doesn't ever "miss". Got new brakes once or twice. Drain and add a gallon of new coolant every 18 months. Original water pump, but have a new one when this one fails. New R. cap ready for OEM. Had to replace 3 starters.. so what!

When my AC went out a year ago I was in a panic (Nassau, Bahamas) and my back yardian mechanic said get a new AC Compressor - after checking with dye for leaks. Been cool ever since, but I don't think AC ever shuts off. Mechanic installed and charged it for $200, and I got the unit off Amazon for $200. Can't beat that.

Here in Nassau its 65 to 100 degrees all year long. Just let the AC run 24/7. OEM AC Compressor lasted 12 years (140,000 miles).

 

Sub'd

 

these deeper pans are not available. tempted for the next time i do a flush
https://yourcovers.com/transpan_11112.php

 

I have also been looking at those.

I wish they would have added a dipstick.

 

that would have been awesome

 

Oh Yeah !! We have to put some pressure on this company to incorporate a dipstick on these aftermarket pans . I guarantee they will sell out in a matter of minutes

 

Alright guys so having a little trans issue...

2013 Tacoma TRD OR 4x4 with a TRD supercharged 4.0 with AFE CAI dry filter. TRD tune to support SC. Installed Ratiotek HD kit 20k miles ago with no issues. Stock gearing with 265 75 16, will be putting 285 75 16 on next week. Fluid level is on point, went with the valvoline fluid vs the OEM when i did the RT kit.

With the cooler weather, I have recently noticed that i have a bad 4-5 flare. It also likes to sit in 4th gear for a while before attempting to go into 5th, and when it finally does shift, it flares. RPM's will shoot up before going into 5th. It is only really on the FIRST 4-5 shift after starting the truck up from sitting all night, and is more noticeable with cooler temps. Once its gotten past the first 4-5 shift, it shifts into 5th after that with almost no issue. Cleaning MAF has no effect, havent touched TB in a while though.

If i throw the shifter in 4 then to D when it hangs in 4th and doesnt want to shift to 5th, it will shift into 5th almost instantly. This makes me think it may be an electronic issue. Have done some searching but haven't found anyone with exactly the issue I've had yet.

I was going to start with a trans fluid drain and fill or two and go from there, but didn't know if there was something else i should be looking at.

Any help is greatly appreciated, thanks!

 

my 13 does it too. only when the trans is cold. once it warms up it's gone. no supercharger but larger trans cooler because i tow heavy

 

@nd4spdbh any ideas?

 

https://shop.ukrtrans.biz/wp-content/uploads/catalogs/A750E.pdf

4-5 flare is definitely more prominent with the TRD tune (likely due to simply extra power and torque of the super as well as different torque tables). From what i can tell a shift from 4 to 5 or 5 to 4 goes "through neutral" mechanically in the trans. Meaning its not just another clutch / brake grabbing or release (like the case in 1st through 4th), Its a full powerflow change wherein there has to be a point in time where the trans is unlocked and power can not flow to the output shaft otherwise the trans would bind up internally. Because of this brief moment where the transmission is in "neutral" you are prone to get a flare, especially if coming from 4th lockup state as the trans will unlock the torque converter resulting in a jump in rpms further exacerbated by the following through neutral before grabbing 5th. The 4-5 flare is typically seen during moderate to low loads / speeds where line pressures are less and the trans logic is to make shifts smoother by slowing things down, further extending this neutral period making rpms jump like they do.

Next cold weather. From what I can gather the A750 trans has some logic in it based on trans fluid temp / engine temp where it wont allow an upshift to 5th if ECT is under a set temp (i think 140*f) To help the truck warm up faster.

Lastly, Moving of the shifter from d to 4 back to d. This is actually a built in function to control AI of the trans itself. If the trans feels the need to hang onto a gear outside of the predetermined shift points, whether it be 4th (or even 3rd on rare occasions) due to climbing a hill (to reduce gear hunting), or it has auto downshifted to 4th or 3rd for added engine braking, you can "force" it back up a gear by doing exactly what you describe D to 4 back to D. Doing that movement essentially tells the trans AI functionality that you the driver want it to upshift and stop hanging onto that gear. In the case of auto downshift, a D to 4 back to D will move one gear up at a time, 3rd to 4th by one D-4-D, then again from 4th to 5th by another D-4-D, But the trans was in 3rd and you wanted to go all the way back up to 5th to "coast" you can do D to N back to D which will result a move all the way to 5th without fuel cut.

 

Great reply
nd4spdbh


I get a lot of private messages regarding this shift flare issue from 4th to 5th and mostly from members with superchargers . Its not something I am too familiar with because of the supercharger tune and I dont see these supercharged trucks on an every day basis . As mentioned above , the transmission gets really busy during the upshift to 5th . It takes time to shut a clutch off , then turn the converter lock up clutch off , then fill another clutch with fluid and apply the locking converter again . Adding a supercharger only exaggerates the circuit when its this busy . The A750e series transmission is well known for releasing the converter clutch very slowly in the stock format . There are many fixes for the slow release of the converter clutch but I believe thats only half the problem when supercharged .
A lot of guys are installing the Ratio Tech HD shift improver kit with their superchargers . I do not believe Ratio tech is aware of this issue . I highly suggest giving Steve a shout and explaining your concerns to him .

My suggestions for the supercharged boys are listed below

There are only 4 or 5 valve body tuners that I am aware of who tweak with the A750 series transmission

Take a look at Sonnax for some ideas as a do it yourself project https://www.sonnax.com/units/390-a750

and Trans-go . http://www.transgo.com/products.php...d=264&countdisplay=1&start=0&addcountview=Yes

Talk with the guys at level 10 to see how they fix this issue https://www.levelten.com/750E_F_VALVE_BODY_KIT_p/toy-ja210-5000sk.htm

Or Talk with the guys at IPT to see if they are aware https://www.importperformancetrans.com/index.php?l=product_detail&p=5439






This being said , even the factory transmissions have a shift flair from 4th to 5th .My own truck has a shift flair from 4th to 5th most noticeable when its cold and only for the first initial upshift into 5th gear . After the first upshift into 5th for that ignition cycle , its good for the day and no more flair . It,s done this since new
I see this a lot on factory trucks . Keep in mind , the transmission has to be warm before the PCM allows the transmission to upshift into 5th and lock up . This is one of the reasons many guys complain it takes sooo long for their trans to get out of 4th
. In the early days of the A750E series transmission , there was talk of filling the upshift accumulators ( cushions ) with fluid sooner but I believe it was addressed through tuning rather than a valve body tweak on the newer trucks 2014-2015 .
I have learned to live with the upshift flair to 5th in my own vehicle . I know when its going to happen and Take my foot off the gas pedal and give the trans time to sort things out . Doing this will prevent further damage to the C2 clutch . Until the aftermarket comes out with a true fix , this is all I am doing about it in the stock format
It takes thousands of man hours to come up with some of these aftermarket fixes possibly removing and installing the transmission and valve body up to 50 times before they get it working properly .

 

@gearcruncher Hey guys ,I have a question! I have a 2008 V6 auto with around 129k . Carrier bearing was changed around a year ago and still have original u joints in drive shaft . I noticed yesterday while driving up a really steep incline at around 45-50 mph when the transmission downshifted from 5 to 4 I had a audible clunk and I also felt it a little in the floor board . Normally I would have hit that hill at a higher speed so the transmission would not have to down shift but as I get older I’m driving a bit slower . Back when the driveshaft TSB came out 2 dealerships said it was fine . Could it just be the u joints ??? I am lifted with Dakar’s and 5125s in the rear and 6112s in front so just under 3” . If I gas it too much on take off I do get a slight shudder also . Any ideas or info is appreciated . Thanks

 

First place I would look is your slip yoke splines , then hit your universal joints with fresh grease and try to re-create the clunk

 

What exactly am I looking for in the splines ? Back and forth movement ? Grab a hold of the drive line and see if there is any movement ?