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

Welcome to the dreaded A750E write up my fellow Canadain lol

5th gear has always been an issue with this transmission . Since new , Even my own truck has a slip during the cold weather on the first shift in the morning . There are a lot of complaints about the slip from 4th to 5th . All I do is take my foot of the gas pedal to eliminate any slipping and after that , the transmission shifts from 4th to 5th fine . It only occurs once every morning . None of the members I know have dropped the valve body for this issue that I know of . At this time , I do not beleive the aftermarket has made corrections to eliminate the 4th to 5th issue by itself , but they do address pressure losses due to valve body wear .
There was talk that Toyota knew about the issue and improved the circuit in the later years 2011-2015

4th to 5th upshift is a very busy circuit not only for the computer and solenoids , but also for the hyrdraulics inside the valve body .

With a high mileage transmission like yours and without knowing much about the history , I would start with a main line pressure test followed by a Sonnax zip kit . The Sonnax kit will restore the hydraulic integrity of the valve body to better than new condition which in turn should eliminate the accumulation problems your are feeling .

 

Well, tonight the transmission seemed a bit better, it doesn't slip (rev jumping) anymore in the cold since the fluid change, but you definitely feel the hard shift still, it's only been a couple days since I did the transmission reset with techstream so going to give it more time and see what happens. My commute I maybe get a total of 4 or 5 shift cycles, so not a whole lot to fully let the transmission warm up

I'm thinking that there's a weak seal inside the valve body that with the colder temps has brought the issue on, which had me look into the sonnax kit.

Is there a how to somewhere to do a pressure test?

Thanks for your input fellow Canadian! I do love my truck, it's the truck I've wanted for a while, after having a canyon and a Dakota. Everything else with it seems alright it's just whenever I have a vehicle with any transmission issue it gets under my skin

 

Perfect tjanks! I did glance at it all but clearly missed it

 

Hello transmission problems. One thing I have not read in here is how to know when the transmission is toast. I recently baked mine in skids filed with mud for several hundred miles. Now I can only drive it for a little bit. Once she warms up it will not go into 1st gear or if challlenged with a hill it stops. Had a major mud episode and belive it is now toast at 165000. I have never serviced this and that has proven to be bad for sure. Did a small flush in the autozone parking lot in baja to get here going again for a 100mile but then as soon as I come to a stop she quits again. I thinks she is done and do not believe a rebuild save it. I will be dropping the pan later to take a look and see the damage. She starts right up at this point and I have moved her around the yard but know that if I was to drive it it would just quit again. Just looking to get some more ideas.

 

That sucks . Post some pics of the fluid and pan magnets when you do it

 

Don't do this. This is after we removed skids and about 200lbs of mud that the transmission pan was baking in!

 

Since it’s gotten Super Cold here, I drive more in 4th & don’t shift into drive until I get some sort of decent fluid temp. Seems to like that a lot better before that first OD up shift.

 

Hi @gearcruncher.. I need a little help with a A750F in a FJ cruiser. This is a rebuild project I have been working on the last 6 months or so. I did a transmission swap the last two days as my old one had a bunch of water in it from a previous owner misadventure. I originally tried a full flush with 15 qts, but drove it and did a check and had pink milkshake again so decided to cut my losses and pick up a used one.

Long story short, I go the new one in, and I will be honest I did not do a lot of research before hand as I didn't know what I didn't know, so to say. I have done tons of other things, but never swapped an auto transmission, so I was leaning on my 18yo son's prior experiences with his friends and there project car misadventures. He is no dummy when it comes to this stuff, but a lot of his knowledge comes from youtube, and there are surely things he doesnt know either.

The new transmission: my son put fluid in the new torque converter, but I think he only put like a half qt in there. He spun it on till it felt like it dropped in and seated. Then we assembled everything, but didnt think to double check torque converter as we manhandled it in, but seemed to go in ok. When we went to do the flex plate bolts, the torque converter was touching the flex plate, but we could spin it and get all the bolts in. We thought we were good. We bolted everything up, reconnected everything. I put 3 qts of fluid in the trans fill. We started the FJ and it started right up and sounded fine it ran for maybe 30-45 seconds before we shut it off. It was past dinner time, so we cleaned up and went on about our evening.

Today I wanted to start it and do a trans fluid level check. It doesnt start. Its like the teeth on the starter are chattering. My guess is we screwed up somewhere and I am wondering to I need to pull the whole thing back out and start over with the torque converter?

Thanks for any feedback.

 

Did you have the flywheel off for any reason ? did you change the starter ? My fist guess is your starter is loose or for some reason the flywheel got cracked during install .
The starter had to be removed to gain access to the converter bolts , but really , in normal removal and installations if the starter worked well before removal , it should work well now that the other transmission is bolted up . I believe the starter bolts to the transmission . I would be checking to make sure the starter bolts are tight as well as the bellhousing to engine block bolts are tight.

Now you say the converter could spin before you put the converter bolts in place , but are you positive the converter spun free ? I ask because there could be some serious complications if the converter was really tight to turn . I have my fingers crossed this didnt happen ?
https://www.tacomaworld.com/threads/2006-tacoma-trans-problem.540510/

 

I thought the converter seemed tight, my son said it was free. Its not like there is any room there to get much force on it. So if it was tight, what do you think, it was not all the way down? If it only ran for 30-45 seconds, do you think I damaged it? If I did damage, what parts do you think are going to be a problem, just off the top of your head? I have the old transmission, and the torque converter is full of strawberry milkshake. Do you think that one is salvagable?

 

Thats just me jumping to conclusions . If there is an issue , you've got all the parts to fix it along with spending more quality time with your boy .
I am taking a step back until you have a chance to look at the truck to figure out the starter .

 

Kinda sounds like a starter clearance/alignment issue to me. Remember when all you needed was a paper clip to check for clearance.

 

Ok well i will take a look. From cursory checking the starter was mounted ok but i need to get in there a little better. Thanks for the advice

 

So to come back to this.. Had family in town and things going on so I put this off as just thinking about it was stressing me out, lol. Fast forward to last weekend I decided to double check everything and turn it over once to see what I could see. Starter looked good, bellhousing correct all the way around. Could see nothing wrong on the outside, but still dreading I screwed up the TC or it wiggled out during man handling the trans in. Well long story short I went to turn it over and battery was dead.. Dead dead. No lights on dash or anything. So I slow charged it for a week and dropped it in Friday night and it turned right over and everything seemed fine. Shifted through its gears and spun the tires with not hesitation or unwanted sounds. So I guess in my ultimate uncanny luck the battery used the last of its juice to turn it over when we first put the tranny in, but by the next am there wasn't enough to power the starter. So at this point it looks like I am sitting pretty. Still have to replace a couple exhaust bolts that broke and do a trans level check, then I will take her out and see how she does..

thanks for the pep talk, @gearcruncher

 

This is fantastic news . Glad it was just a battery issue

 

Any idea what would prevent me from getting into the temp check mode? I jumped 4 to 13 on the OBD, get all the flashies, and go to neutral and back and forth with drive and it will not enter temp check mode.

 

https://www.tacomaworld.com/threads/cant-enter-temp-check-mode.369940/

 

Awesome. I had to go to 4 to get mine to work. Interesting.

 

Just looking for any insight. I have looked on numerous threads but haven’t found my exact issue. My bro in law has a 06 tacoma 4.0 auto 4x4. The truck is giving me a po2714 and a po2757 codes. The truck will drive forward when in neutral and will start to drive forward when shifted into reverse then act like it jumps out of gear but won’t reverse. Place it in park and shut it off acts like still has pressure on tranny. When taking truck for drive it seems if left in drive it jumps outta gear but move to 4 th and seems to shift fine. Truck has high miles at 508000 kms not sure if original tranny or not. Any help be appreciated.