Hipatchy

I have an '01 I bought with low miles. Sat for a while before I bought it.
Transmission was good for the first year of ownership but it started exhibiting the following:
- low and mid throttle acceleration the transmission will stall or "flare" I have heard it described. It will accelerate normal while in the gear and when it goes to shift it feels like the gear is completely disengaged for a split second and then into gear fast. You get pushed forward on gear changes.
- hard throttle acceleration the gears will have a slight delay and bang hard

I have:
- changed the fluid. it looked nice and red before, no burnt smell. Done multiple flushes. Total around 12L I put through. Problem was there before flush.
- checked the level about a dozen times. I can get a good reading on the 01 on the dip stick. I have it set at right in the middle of low and high.
- tried running a quart over and quart under, no change.
- cleaned both transmission speed sensors
- cleaned maf, throttle body
- changed engine temp sensor
- changed transmission mount and engine mounts

Looking for any other advice.
I worry it is solenoids or valve body but it does it on 1-2, 2-3 and 3-4. 4-5 seems fine.
I don't feel any slipping it pulls hard when in gear.
I thought maybe pressure is low and the filter could be the cause but reading shows the filter is more of a mesh and doesn't need to be changed.
A side note is when I have a fresh oil change it doesn't do it for 50-100 KMs. This one puzzles me.
Cheers

LILEVO

iTrader: (1)

Any video of it happening? Could be quite helpful to diagnose.

I had issues I swore were transmission related and ended up being clogged cats. First Toyota I've ever had that I had to change the cats on. Didn't think that was a thing. Very harsh up/downshifting at freeways speeds up and down inclines. Mine has 225k though. Might not be the case with a lower mileage car like yours. Transmission issues on a low mileage car are also quite odd as well.

DrZedex

That might be ECU related. They're known to fail in ways that cause some of what you describe. There are rebuild services for them.

Striker223

Not sure without feeling it in person/having access to the car, the 2-3 shift normally has a slight "gap" due to the trans needing to fully release the drum and come back in but it should be barely noticeable at all.

jharris400

That's common for 04+ with the 6 speed transmission, the older 5 speed doesn't commonly have ECU problems.

DrZedex

I stand corrected.

Hipatchy

I have watched the tach during shifts and it will bounce around a little bit but not always. Most of the time it looks normal. Hard to video the problem as you just feel delayed / hard shifts but I'll try and capture. Cats is an interesting thought. I sometimes smell rotten egg on hard acceleration. Hard to believe they are bad though as the car has 133k Kms. Tried all brands of gas but doesn't seem to matter.

mikaelse

Are you using the correct ATF ?. These transmissions are fussy. Toyota IV or a proven equivalent is the way to go. I use MOBIL ATF 3309 for cost and availability reasons. I have used about 30 liters of it by now in my two LS 400 with 4 and 5 speed and they work great.
It is possible that someone has used the wrong ATF on your car and you are still working on getting rid of it. Doing drain and refill of 2 liter 6 times with drivning in between still leaves >20 % of the initially present old oil. there is almost 9 liter total in there.

430SLOwner

Saved the following instructions read from some thread in the forum (have not done as trans seems fine, but some wrote got good results)

process to reset the trans:

a. insert key

b. turn key to on, no start

c. press gas pedal to floor

d. hold pedal to floor 5 seconds, key to off position, then release gas pedal

e. wait 2 minutes

f. remove key.

Hipatchy

Car shifted perfect when I got it. Original fluid I think. Then it presented itself. I changed the fluid myself and ironically I went to the lexus dealer and told them model and year and they have me WS. The car shifted way worse. I did research and found out this was wrong and flushed it out with disconnecting the transcooler line. Ran 8l through it then did 2 more drain and fills. Shifts better after going to TIV but put me back to where I was with original fluid. The difference in fluid can definitely can be felt. Maybe I will try 2 more drain and fills for the hell of it but it started out of no where in the first place.

Hipatchy

I'll give it a shot. Thanks for the idea.

mikaelse

I am no expert but someone else here may know how fussy these transmissions are. You may now have ballpark 20 % of the old+wrong stuff still in there A tip is if possible lift up car in front and wait over night or more prefferably longer. I have during DIY sessions ( weeks ) managed to get close to 4 quarts/liters out that way when doing drain and fill. Was a surprise to me.