Toyota Grande CVT Gear Problem

pwuser151804282637 (Fair Deal Enterprises) 2020-03-05 06:17:46 +0500 #266

Pls also see my last Reply above and also check VB Condition of Valves.
What makes me think that Torque convertor can be fine is that After VB service there.s alot of improvement in Engagement jerk. 8 out of 10 times there is now no jerk when the lockup Happens.

About water contamination : No Not possible. Impossible.

khuram2703 (MAK) 2020-03-05 06:50:42 +0500 #267

Same situation...... shudder minimized .... Could be due to ambient temp elevation as compared to Dec / Jan....

TypeA (TypeA) 2020-03-05 09:38:33 +0500 #268

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anon36782927 2020-03-05 11:04:06 +0500 #269

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pwuser151804282637 (Fair Deal Enterprises) 2020-03-05 14:33:16 +0500 #270

How to identify such situation?
Whenever the fluid was drained the condition was good and also the colour. I have done fluid drain 3 times till now.

Xulfiqar (Xulfiqar) 2020-03-05 20:33:45 +0500 #271

Yep - quite commonly seen on cars with buzzing torque converters.

Xulfiqar (Xulfiqar) 2020-03-05 20:36:37 +0500 #272

You need to do an oil analysis for this, or get a glycol test kit for ATF/CVTF - the glycol and water peels off the clutch friction material from the metal backer plate which causes shudder/buzz/drone on the TCC.

to understand this more, google for nissan or mercedes ATF cooler failure or dodge NAG1 water leak into transmission (it was due to a weak O ring on the charging/testing tube of the transmission.

pwuser151804282637 (Fair Deal Enterprises) 2020-03-05 22:45:32 +0500 #273

Bro today i confirmed that rocket science material AC on and off behaviour.

Using techstream :
When Ac is on The Minimum speed Slu and Lockup is off is 40kmh
When ac is off - This minimum speed comes to 18-20kmh

(Driving with AC on the Car seems like 90% perfect)
(Driving without AC on , the Car Jerk Like a donkey Near 40)

What i have observed : When Driving with ac On around 40kmh then as soon as i Took my foot of accelerator pedal the Car Unlocks asap - Slu also gets off - the Rpm on speedometer also Rises - and when i again place foot the car Tc slips and all is silk and smooth.

In case without ac off since i have started this thread didnt use ac as winters here , around 40kmh speed The slu stays on and only goes off when i hit 20kmh speed. So nearby 40speed during traffic with slu on when i place foot the car judders. Similarly if i brake around 40 car jumps forward.

If the slu gets off nearby 40 50 - Life will be as great as it used to be since a oil change.

TC : Its silk smooth and well - No jerk if sliping , No jerk on application , no jerk on de applications.
The problem is with slu Soleniod behaviour.

Xulfiqar (Xulfiqar) 2020-03-05 22:56:40 +0500 #274

the lockup is partial - not an on off situation, the lockup starts to slip the clutch to 80% application at that low speed and fully locks after the ECU gets msg over the bus from the SRS unit that acceleration has been reduced (dynamic rolling torque requirement is low)

I know I may sound stupid and confusing, but thats how it was explained to me when I was chasing my tail on these pieces of trash transmissions.

btw - why dont you use A/C in winter? - its used for defogging the windshield.

another point - the SLU behaviour is not alone as it passes through a pressure balancing circuit and relies on the "stiction" characteristics of the clutch and the oil combined to give a smooth transition.

haseeb.basharat 2020-03-06 00:30:18 +0500 #275

Not possible at all in a new car.

haseeb.basharat 2020-03-06 00:30:56 +0500 #276

His car is perfectly normal. Case closed.

Xulfiqar (Xulfiqar) 2020-03-06 00:35:46 +0500 #277

LOL

want to bet on it?

pwuser151804282637 (Fair Deal Enterprises) 2020-03-06 00:53:50 +0500 #278

Brother ap case close krlien pehlay Hamari kher hy ,
I have opened this case here and i think i am supposed to close it or Mark is as solved.
4 out of 5 people found it as Faulty after drive Who are you to judge , have you drove it once?
I have spent more then a month and more then 25K-30K over this Problem and its still unloved. 3 People have contacted me after reading this forum asking for solution.
Still waiting my Answer and solution - Still no way out.
Please don't comment on it if you cant help atleast.

pwuser151804282637 (Fair Deal Enterprises) 2020-03-06 02:57:01 +0500 #279

Sure about Ac i would have used it in winters if i knew it before , The way transmission jerked - I can feel there will be damage inside but didnt knew about this ac thing.

I got your point of partial lockup and stiction characteristics of TC But Still a mystery why is the SLU Behaviour changing with ac On and ac off. With ac on Minimum Speed for de application is 40kmh but with off its onlt 15 20 speed.

I will also drive my friend fine grande and will observe De application of TC With ac on and ac off and see differnce compared to My car.

Xulfiqar (Xulfiqar) 2020-03-06 02:58:08 +0500 #280

on CVT the SLU works very very early to help start moving the car (highest torque requirement)

Have you tried to relicabrate the acceleration sensor yet?

haseeb.basharat 2020-03-06 03:15:19 +0500 #281

Yeah. Coz that jerk is normal. It's a part of k313 cvt and mentioned in its manual as well. 40-60km/h jerks are normal. Op will ignore it once he will go beyond those speeds.

pwuser151804282637 (Fair Deal Enterprises) 2020-03-06 03:33:23 +0500 #282

Okay Understand ,
Acceleration sensor calibration , are we talking about zero sensor or De acceleration sensor i can only find these in utility tab of techstream.

rajaatta (Raja Atta) 2020-03-06 05:53:27 +0500 #283

A request please let the good work rolling. As the OP has already spended a large some of money on it let it roll for good of others.

Btw OP why dont you order a new Valve Body Assy to get rid of this problem. As seen the old one has been already messed up.
Excessive jerk along with slippage indicates some thing has gone wrong during valve body service or after it. Had you pumped the fluid in valve body assy before installation?
And did you filled the chamber with lot of extra fluid to avoid running the tranny dry?
These were the important points which has to be followed and these are not available on internet . That's why DIY is a dangerous scenario for CVTs service. We have lost hundreds of these transmissions and learned how to deal with the servicing.

I fell sorry for your loss but without test driving it the real scenario is still a mystery.
Excessive jerk or shrudder during ratio shift can be caused by TCC failure or forward drum not getting enough pressure and engages when it receives the fluid with shrudder.
These both are different scenarios and we can't diagnose it over verbal explanation.
Parameters diagnosis is also not possible as you had wrote that shrudder has jumped in after servicing the VBA which seems to be the fluid doesn't pump up after service and probably damaged the FCD .so now wait for some one to get it test drive to confirm the symptoms or keep driving it until the scenario gets severe.

Note one thing observe the AT temperature in city driving of 3-4 hours and post us about it if it rises more than 88 C then serious damages has been occur or slippage is present if it maintains in between 88 to 93C and starts to lower down as you get on highways then there are no damages and things can still be fixed

TypeA (TypeA) 2020-03-06 09:32:27 +0500 #284

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haseeb.basharat 2020-03-06 20:31:47 +0500 #285

Why everybody here want proof of everything? Is this a court or what? Yes I read it like 2 years ago. I will share when I'll be able to find this.

If that was the case then his transmission would be dead by now.