[i74js]

Originally Posted by audioholic

In contrast to the implementation on the 1.3MJD, the clutch control is hydraulic in the manual version. This is directly automated by the AMT and there is no intermediate setup. Hence, the AMT unit can have better control on the clutch engagement and disengagement by being able to vary the pressure on the clutch slave cylinder directly. This is what results in smoother control and no complaints of judder or jerks heard till now by the users of the diesel AMTs and even the Dzire petrol has a hydraulic clutch I suppose.

Thanks for sharing this information. AMT is used in some very high end cars too, which is not even known to customers; and it operates flawless !

To me it seems that the success of AMT is typically linked to availability of low end torque, which is sufficient in case of oil burners (even with small engines) and is not sufficient for small petrol motors, which results in RPM building up and clutch slipping / car going out of control of the driver.

This needs a technical fix at the drawing board itself else the tested TC and CVT are lovely solutions which if produced at large scale will not be uneconomically looking at the "under warranty" replacement costs (a clutch set replacement is about 12-15% of the cost of AMT unit sourced by MSIL, excluding the labour payout to dealer for under warranty replacement) to the manufacturer and an unsatisfied customer, that results in a poor brand perception.

[k88k]

Originally Posted by deetjohn

Also, I think MSIL has tuned Alto AMT very conservatively compared to the Celerio AMT where the drive-train behaves in a much better way on road.

I have not faced any issue with my Celerio AMT which has done close to 19.5K Kms, except an instance when I faced a minor judder when I was taking the car out of parking after a stop after a long drive, which IIRC was around 15K Kms. May be I went too hard on the pedal while turning. Mine is a Oct/Nov '16 manufactured car.

Usage pattern also explains the judder here, as the OP spends a lot of time in traffic, the juddering is being experienced very frequently and noticeably. I take the car out only twice a week and haven't driven much in traffic. Having said that I have had a good experience with AMT so far, I still would not recommend AMT on smaller engines because of the negative feedback the AMT has garnered since its launch in such cars. Will also make it a point to get information from MASS on AMT issues being faced by others and preventive parts replacement if any required during 20K service.

[bkc]

I've not driven an AMT which had issues, but, going by issues, the clutch seem to wear out faster than normal.

This points to only one issue, excessive half clutch usage by the AMT system.

I've noticed a peculiar issue with Gujrati ECU (auto clutch), once you pickup speed, apply brakes to slow down and depress brakes later, the ECU puts the clutch at half clutch, all the time, until you touch the accelerator.
It means, the vehicle would keep moving at half clutch, until it senses any accelerator input. If the road is a complete descent, the clutch will keep itself engaged at half clutch throughout, until you tap the accelerator. I'm relating this to AMT and may be the issue is similar.

We all know, in case of non-hydraulic clutches, the clutch travel changes throughout it's life (until adjusted). IMO in AMT, these travel ranges are preset and with time, it needs to adjust itself, even if this mechanism isn't effective, the clutch won't depress to a required level and lead to juddering.

These are just my analysis and I may be wrong too.

[turbodude]

A couple of my close friends have Celerio AMT. The information received from them is equally shocking.

One of my friend gave his Celerio for servicing in October 2017. When the driver came for pickup, he noticed that the driver is using his both feet for driving the AMT car. While he warned that driver for using both feet, the driver said we all do the same .

My friend complained to the Maruti dealer but till date no apology or acknowledgement was received. The dealer is a reputed one and there are hardly any negative reviews against them so my friend asked me to withheld the name while posting this.

PLEASE DO NOT USE BOTH FEET WHILE DRIVING ANY AMT CAR. It damages the ECU. I have taken test drive of Celerio and showroom personnel had informed me that using both feet is forbidden.

I wonder why Maruti had not included this warning in the service manual.

[vsathyap]

Originally Posted by SS-Traveller

Does your car have a tachometer (I believe it does )? Does the rpm fall when the "jerky jump" happens, or is there a surge in revs?

Yes it does and coincidentally I was planning to record the readings from my OBD2 adapter through the TorquePro App (plot it on a graph basically and put the image here on the parameters like Engine RPM, Load, Throttle Position and OBD Speed). I haven't observed the tachometer while the jump happens - perhaps am more worried about controlling the car and will report the same.

Originally Posted by varunsangal

Suggestion: Try to press the accelerator a little bit when starting from a dead stop, if the traffic demands immediate deceleration, slip the auto box into N.
In subsequent gears the problem will not arise as the accelerator would be pressed already.

Pressing the accelerator while the creep is happening worsens the problem as the car enters the "half clutch" zone and this is the point where braking power gets compromised and my panic face sets in. I do this in stop and go traffic primarily since the creep is too slow to start moving the car (the gap in front widens and traffic goes nuts honking!) and a little dab on the A pedal makes the car lunge forward and I don't have full braking power since it wants to move ahead.

Originally Posted by deetjohn

It's no secret that AMT is best suited for bigger engines which has more torque in the lower RPM. So, the best integration of the AMT I have driven is the 1.3 MJD.

Maybe the K10B with its very poor low end torque isn't really suitable for AMT and ideally needs a torque converter where the transmission supplements the torque output at lower RPM. But then, MSIL ditched that for cost efficiency and F.E. And the market lapped it up.

Also, I think MSIL has tuned Alto AMT very conservatively compared to the Celerio AMT where the drive-train behaves in a much better way on road.

Absolutely true - engines with poor low end grunt don't go well with the AMT. It's hyper-tuned for fuel efficiency and spends eons rotting in second gear, even though I'm in walking-speed territory. This is when I take matters into own hands - move to M and downshift to 1.

To get an idea of the gearing, this is how it feels in D mode:

1. Very short 1st gear, eager to go into second.
2. A l-o-o-o-o-n-g second gear; AMT loves to be in this gear even though my speeds indicate I should be in 1st, given the poor bottom end.
3. A non-existent 3rd gear - merely there to act as a placeholder since the gear shifts are sequential
4. A "too soon" 4th gear - the car doesn't have the kerb-weight to keep the momentum gained in 3rd going; one little slowdown and it flips to 3rd and almost instantly to second and it's found it's comfort zone of sorts.
5. A properly placed 5th gear which kicks in at the right time.

IMHO, the AMT on the K10 is very very suitable for highway driving (or similar - with relatively free roads where there is not much 2-3-2-1-2-1-1-2-3-2 shifting) and it brings a smile on my face on how well it downshifts in scenarios like overtaking or when we need more power. It's the city traffic which brings it to it's knees. This point is probably the key which divides opinion of folks who have driven these cars for long and don't have any issues, while some have experienced juddering issues early on and continue to suffer like me.

Basically, the passengers in the car look like they are riding a camel - constant forward and backward rocking when the AMT changes gears (downshifting to 2 and 1) and while it moves from a standstill from the 1st gear (the "AMT head nod" has become the "AMT Camel ride" in my car). Given the lovely soft suspension, High GC for a car of this profile, poor tyres and handling, it indeed feels like a salad bowl/washing machine.

[Satishtv]

Guys, just wondering, have heard about the AMT issues in Maruti & Renault cars. But, never have I heard any issues from tata car owners. Do Tata cars not face any issue with the AMT? Is it because all their cars equipped with AMT are 1.2 litre models?

[Dry Ice]

Originally Posted by Satishtv

Guys, just wondering, have heard about the AMT issues in Maruti & Renault cars. But, never have I heard any issues from tata car owners. Do Tata cars not face any issue with the AMT? Is it because all their cars equipped with AMT are 1.2 litre models?

Could be. But there is also the matter of sales numbers.

Maruti sold about 67k copies of models which have AMT as an option. Kwid + Tiago sold about 15k combined.

If you consider 10% were AMTs, Maruti sold ~ 6700 AMTs and,
Kwid + Tiago sold ~ 1500.

Out of this, if 5% are reporting issues - you have 340 odd cases from Maruti, and 45 odd for Kwid + Tiago. So, you are likely to hear 1 Kwid/Tiago owner complain against 7 of Maruti.

[sachinayak]

Originally Posted by Dry Ice

Could be. But there is also the matter of sales numbers.

+1

That said, even on the AMT woes thread, almost all complaints are from Maruti Owners and I do not recollect anyone reporting issues on Tata Motor vehicles. Most surprisingly not even Tata Nano AMT users. This uses a puny 624cc, twin-cylinder engine with 37 BHP and 51 Nm of torque.

If poor low-end torque was an issue, there should have been multiple complaints with the Tata Nano AMT (and believe me, even the smallest issues with Tata Vehicles gets highlighted in a big way).

Guess, for a change Tata Motors may have got their tuning with the AMT systems better than the market leader. Also they have a sport mode with their AMT offerings, unlike their Maruti counterparts (not true if this still holds true, but definitely was true during corresponding vehicle launches).

[itwasntme]

Originally Posted by vsathyap

Thank you for your inputs GTO. Yes, its quite unnerving to drive the car in tight traffic, specially after driving in heavy traffic for 30-45 minutes. The juddering and jumping become more and more aggressive as it gets heated up.

Hope this is getting resolved quickly? I know it's easier said than done but please consider avoiding usage of the car till it's fixed.

God forbid if your car jumps forward in heavy traffic and traps a 2W rider (or a pedestrian crossing in front) against the vehicle in front! Quite apart from the legal and financial mess you may get into, the fact that you KNEW about the fault will haunt you for the rest of your life.

[Satishtv]

[quote=sachinayak;4306493]+1

If poor low-end torque was an issue, there should have been multiple complaints with the Tata Nano AMT (and believe me, even the smallest issues with Tata Vehicles gets highlighted in a big way

+1 to that, it is even more surprising given that both Tata and Maruti source the AMT transmission from the same manufacturer.

Has anyone heard of AMT issues with Ignis or Dzire? These come with the 1.2 litre engine. Very curious as I plan to buy the Ignis AMT.

[SS-Traveller]

Originally Posted by vsathyap

...I was planning to record the readings from my OBD2 adapter through the TorquePro App (plot it on a graph basically and put the image here on the parameters like Engine RPM, Load, Throttle Position and OBD Speed). I haven't observed the tachometer while the jump happens - perhaps am more worried about controlling the car and will report the same.

Any progress on the OBD-II readings?

[jeepster_chd]

Originally Posted by sachinayak

+1

Most surprisingly not even Tata Nano AMT users. This uses a puny 624cc, twin-cylinder engine with 37 BHP and 51 Nm of torque.

If poor low-end torque was an issue, there should have been multiple complaints with the Tata Nano AMT (and believe me, even the smallest issues with Tata Vehicles gets highlighted in a big way).

We have a Tata Nano AMT at home and it is wify's daily drive to office. Most of the time I drive it on weekend's or in the evening for daily chores. Here are my two cents on AMT thingy: AMT on NANO especially is a tricky thing to master on. You have to unlearn the way we are used to drive and learn it do drive the NANO way. Initially, I would fear stop-go traffic (due late crawl and sudden jump on pressing accelerator), I would try to race on to the inclined driveway at home and would get struck mid-way and same with passages in malls.

However, over the last two years, I have realized the car's strengths and weaknesses and NANO has never let me down. We talk to each other and journey is always smooth. Regarding the issues or specific problems with the AMT unit there have been none. Tata has done a good job in almost all aspects.

[amalji]

Originally Posted by deetjohn

It's no secret that AMT is best suited for bigger engines which has more torque in the lower RPM. So, the best integration of the AMT I have driven is the 1.3 MJD.

Maybe the K10B with its very poor low end torque isn't really suitable for AMT and ideally needs a torque converter where the transmission supplements the torque output at lower RPM. But then, MSIL ditched that for cost efficiency and F.E. And the market lapped it up.

The AMTs on the K10 engine works really well when it works. I've driven the Celerio AMT on the same engine extensively and I prefer that any day over the Nissan Micra CVT which is technically much more superior.

Here, the problem seems to be related to the durability of the kit. Regardless, I have 2 of my friends using AMTs and none of them have faced issues till now. One car is 2 years old and the other one is 9 months old. Both are Celerio AMTs with K10 engine. Both my friends love the AMT experience as well.

[vsathyap]

Originally Posted by SS-Traveller

Any progress on the OBD-II readings?

I've been a little busy with work and other household chores this week. I'll get back to update this thread soon. I haven't had a chance to do much related to the car. I've been trying to reach my SA at the dealer but am unable to get through his phone. I may walk in sometime next week if phones are still busy/not reachable.

[archat68]

Originally Posted by vsathyap

To get an idea of the gearing, this is how it feels in D mode:

1. Very short 1st gear, eager to go into second.
2. A l-o-o-o-o-n-g second gear; AMT loves to be in this gear even though my speeds indicate I should be in 1st, given the poor bottom end.
3. A non-existent 3rd gear - merely there to act as a placeholder since the gear shifts are sequential
4. A "too soon" 4th gear - the car doesn't have the kerb-weight to keep the momentum gained in 3rd going; one little slowdown and it flips to 3rd and almost instantly to second and it's found it's comfort zone of sorts.
5. A properly placed 5th gear which kicks in at the right time.

Those who are wondering about why there are not much complaint about the tata amt cars I'll share my experience with the tiago amt and will give the differences between the two cars difference in gear shift:

Tiago upshifts to 2nd gear only after you crossed 2000 rpm and lifted your feet off the a pedal. If you're holding onto the a pedal it'll shift after 2500 provided you aren't pressing it too hard. In that case it'll shift at around 3000.

The behaviour is similar in other gears too. Also if you're on a incline it would upshift a little later at higher rpm.

Also the shift from 3rd to 4th is a bit late always at around 2200 instead of 2000 in other gears.

This is all in city mode. In sports mode the car shifts gear a bit later.

However driving the amt is a challenge if you're coming from a manual. Also you need to become a bit sedate to avoid the jerks between the gearshift. In tiago the jerk/lag while shifting from 1st to 2nd is most noticeable and annoying. Others are tolerable.