Team-BHP - Tata Nano: AMT shifter motor failure

Thought of documenting this issue as I feel it's significant enough.

Last week our 2016 March, Tata Nano, run a shade under 14,000kms , was diagnosed with probable AMT shifter motor failure.
The problem manifested a couple of weeks ago when the Nano used to shift into neutral ,on its own, irrespective of vehicle speed etc and coast to a halt, with no ratios engaging. Wait for half an hour , then re-cranking the engine sorted things out , only to have it replicated in the next 5 Kms or so.

At first I thought it was a clutch issue but having driven a multitude of cars of various ages and types over the last god-knows-how-many-years , I had a general idea of what usually preceded an impending clutch failure, slight juddering, snatchy shifts, jerks while selection, faint noises from release bearing etc, and none of those symptoms however faint it may be made its presence felt in the Nano.

Hence I was convinced that it was not a mechanical clutch issue but something electrical. Got the vehicle towed to Lexus Motor's Kolkata to have it worked upon and after quite a bit of diagnostics it was determined with a large degree of certainty, that the erring culprit is on all probability, the AMT shifter motor. Here , I must mention the excellent service levels of Lexus Motor's staff. Not only they did a thorough "intellectually approached" logical diagnosis, but kept me informed at every step of the way. As I write the vehicle is awaiting parts for replacement .

Now my question is: An AMT kit is supposed to last the product lifecycle of the vehicle to which it is being bolted irrespective of OEM, brand, model or variant. That is a given and the minimum expectation. Then how come such a major failure cropped up in such an early stage of a vehicle's life?
Investigating further, I came across, fellow T-BHP'ian, Skyline_r34's post of AMT failure in his Nano. This was a mirror image of what happened with my car.

Curiosity sufficiently piqued, I started moseying around various TML dealerships & got to know that the AMT kit was widely used as a common component across various Tata models , namely : the Nano AMT, the Tiago and Tigor AMT's and also the Zest AMT.
And sotto vocé, I was also told that the other models had also witnessed problems of the same kind.

What gives ? How come such a critical component, designed for a very, very healthy operational life , go kaput just like that?
I suspect a deeper malaise here. Is it that a particular AMT batch was at fault and went undetected ?

And what would've happened had the AMT failed out of the warranty period ? Or let me put it this way, what is the assurance that the AMT components will hold up second time around ? Can TML give some assurance / warranty as to the same ?

Would like to know T-BHP'IAN's views whether they or their near and dear one's have experienced such AMT issues or not. Maybe we can compile all AMT issues on a single thread as a ready reckoner.

Meanwhile , I'll continue to update as to the fate of our Nano. But definitely my confidence as to the long term reliability of the product and taken a backseat.

Quote:

Originally Posted by arjab (Post 4591240)

What gives ? How come such a critical component, designed for a very, very healthy operational life , go kaput just like that?
I suspect a deeper malaise here. Is it that a particular AMT batch was at fault and went undetected ?

And what would've happened had the AMT failed out of the warranty period ? Or let me put it this way, what is the assurance that the AMT components will hold up second time around ? Can TML give some assurance / warranty as to the same ?

I am aware of a 2016 model AT nano refusing to climb a ramp and appeared to be in neutral and just revved Instead of moving. After shutting down for a few minutes it worked fine afterwards.

There is however one thing to note about that Nano, its rarely ever used, it may not be an acceptable behavior that something that sits idle goes bad but it can be a contributing factor.

The parts that are replaced should come with warranty , just for that bit, unless it's a consumable.

I used to own a GenX XT , absolute marvel of a car.

All AMT cars currently in the Indian market faces problems by the time they are in the 15-20k KMs . My colleagues Nano AMT refuses to get out of even the slightest road side border. Some of our roads have been recently renovated making them significantly higher than the borders. And the Nano just goes into the neutral and keeps revving. There is no solution other than attempting it again after reversing and building up momentum. Mahindra TUV AMT was another notorious one. They have discontinued the model now. Only one that I haven't heard problems about is the Santro AMT , but since it is a recent model , there may not be many examples that has run 20k kms .

Update:
Work completed & received the vehicle today, a couple of hours ago.
All work was done under warranty and nothing was charged. The Tata dealer also threw in a complimentary wash & polish.
The DC motor controller which monitors the shifting and primes the pump to build up hydraulic pressure had gone kaput and was replaced in its entirety.
The service centre admitted that this failure, was indeed a rare case, as usually these units are sealed for life.
No written warranty has been given on the replacement part though - so i guess - in case it conks off a second time with the vehicle out of warranty, I'll have to pay for its replacement. The price is in the region of 5000 rupees plus GST & labour.

The vehicle, fingers crossed, is running fine. In fact , slightly better than before, because, I guess of all the adjustments and proper tolerances set correctly at the time of replacement of the motor.
Shifts are now being smoothly executed and the
"head nod" has reduced considerably. Manual downshifts also "seem" a tad jerk free.
The unpleasant "clack" sound on selecting reverse has practically been eliminated.

Also this time I felt the quality of TML's after sales service has definitely gone up. I was kept informed of the vehicle's status on a daily basis. Even parts despatch status were updated. Timelines were clearly estimated &
communicated regularly. In fact I received the car before it's estimated date of delivery.

Now I hope the vehicle will be reliable and not go for another sabbatical ! Fingers crossed!

Had the same issue.
Gear number blinking on the dashboard and gear goes to neutral, as the stick remains at D.

Aadya, Eerannapalya, Bangalore is quoting 65k for the replacement of something.
Car is 2015 Sep. 48 months warranty period over.

Quote:

Originally Posted by Kosfactor (Post 4591265)

AMT was supposed to be the economical alternative to CVT and Torque Converter automatics! Although it's not a simple bolt on, it's really not a very hard technologically addition.

No doubt it's a wonderful car, yet IMHO, the Nano is somewhat still alive because it has the AMT version too. This is coming from someone who owned a manual one from 2010-17.

Quote:

Originally Posted by iwant2go (Post 4748899)

The whole AMT Unit + Clutch kit shouldn't cost that much! The thread seems very relevant after reading your post. If possible, please elucidate the whole scenario. Also, have you contacted the higher management at Tata Motors about this?

Quote:

Originally Posted by GrammarNazi (Post 4749522)

The AMT unit is a sealed one which does cost upwards of 60K to replace. If it fails, then that is equivalent to the mechatronics of the VW DSG failing and it has to be replaced with a new one. But failure at 14k kms as in the first case is premature and TATA must consider giving goodwill warranty. And no this is not the gearbox and the clutch. They are separate. The AMT unit has the hydraulic pump and accumulator, gear selector actuators and clutch actuator. The gearbox will remain as it is, while the AMT box is replaced.

Lexus motors is a very good company. They are genuinely interested in resolving your issue, although they take their time.

Having said that, I don't understand why Tata or Maruti or Renault did not bother to do long term tests on their AMT cars. Good manual clutches last for over 70k kilometers even in Taxi versions of the Dzire, Zest or XCent. There is 0 justification for any transmission failure below that threshold in any automatic in any car. And automatics are supposed to be designed for the city. None of the companies have an automatic transmission yet, and all of them bought the magneto mirelli parts from Fiat. I wish such incidents prompt them to develop a reliable cost effective system in India.

Quote:

Originally Posted by Nissan1180 (Post 4749621)

Having said that, I don't understand why Tata or Maruti or Renault did not bother to do long term tests on their AMT cars. Good manual clutches last for over 70k kilometers even in Taxi versions of the Dzire, Zest or XCent. There is 0 justification for any transmission failure below that threshold in any automatic in any car. And automatics are supposed to be designed for the city. None of the companies have an automatic transmission yet, and all of them bought the magneto mirelli parts from Fiat. I wish such incidents prompt them to develop a reliable cost effective system in India.

For an AMT, the more the shifts and crawling traffic, higher is the wear and tear. That is the case for any other automatic transmission as well, but if you consider the mechanics, the workload is least for a CVT and greatest for a DCT or AMT. There are multiple actuators that work continuously to get things done. Hence, if you are driving in conditions that require frequent gearshifts, frequent clutching, it is natural that the AMT box will be doing more work. The same DCT and AMT in say a European country might not fail at all. I have seen VW cars in Germany with more than 2L kms on the odo with the DSG box not having any issue. But that isnt the case in India. I am not sure if any manufacturer would have tested these cars only in dense traffic conditions. It would have been a mix of all roads, and mainly from a test distance perspective, it would be the highways so that they can rake up miles to show XXXX number of kms tested.