[Sutripta]

Long time back Gabriel people used to roam in petrol bunks with a contraption which would measure suspension response to a step response. In a bid to show car owners that they need to change the shock absorbers.

Wonder if that contraption ( a fairly simple one, actually) is available somewhere. In some scrapyard, or warehouse.
Wonder if the accelerometer in a smartphone is good enough for this.

Regards
Sutripta

[vibbs]

S cross is highly localised right? How can we expect same imported components in S Cross as can be found in Vitara outside and at the same time also expect the prices to be competitive?

[CaliforniaKnight]

Originally Posted by Sutripta

Long time back Gabriel people used to roam in petrol bunks with a contraption which would measure suspension response to a step response. In a bid to show car owners that they need to change the shock absorbers.

Wonder if that contraption ( a fairly simple one, actually) is available somewhere. In some scrapyard, or warehouse.
Wonder if the accelerometer in a smartphone is good enough for this.

Regards
Sutripta

Hello Sutripta, Oh really, I was not aware that such techniques existed. However, at NEXA these days they have this suspension testing machine where you can check the health of your cars shocks.
One of my friends have proceeded with this test at a reputed private garage and I am attaching the test results below. To find out the shock absorber effectiveness a simple bounce test as shown in the first post is a good indicator for the condition of the shock absorbers.
In the below video, shocks were removed at the service center and a simple compression and rebound test was done. The test also included, to check if the the shocks were stuck. Again, in the video, if you take a look when the compressed shock is released the rebound is too fast.
After complaints and exchanging e-mails, about the old shocks being inadequate a pair of new shocks and springs were added under warranty. Before the new shock absorber was fixed we did the same compression and rebound check. The old shock and the new shocks were identical in the rebound. Kindly have a look at the videos and share if you have any suggestions.

Originally Posted by vibbs

S cross is highly localised right? How can we expect same imported components in S Cross as can be found in Vitara outside and at the same time also expect the prices to be competitive?

Hello vibbs, We are not asking for the imported components from Maruti, what we would request is to offer us the same suspension specification without under engineering them.
In the name of localisation or competitive pricing, the customers should not be given sub standard components or less than optimal performing shocks, brakes. The result of such an exercise would be disastrous and safety of occupants is compromised. In many cases, it could lead to fatal accidents which would be unacceptable. There is a lot of material published by shock absorber manufacturing companies about the risks of using defective or sub standard shocks.

Below is the video of the rear shock that were removed from an S cross 1.6 at 40,000km.

https://www.youtube.com/watch?v=lGS39MKMCeM

Next we have a video of a brand new shock going in for the same car. This is the new part that is changed under warranty. We took a video to compare.

https://www.youtube.com/watch?v=HAc1ook0KjE

Now, we head to the suspension test center and there shouldn't be a reason to worry, because this is brand new set of shocks and springs.

Look at the test report below.

In the picture above, you can notice that the brand new shocks and springs at the rear are only working 10% and 27% which suggests a defective suspension. This as per industry standards is fatal and a sure shot recipe for accidents, especially during panic situations and hence not recommended.

[Kosfactor]

Originally Posted by CaliforniaKnight

In the picture above, you can notice that the brand new shocks and springs at the rear are only working 10% and 27% which suggests a defective suspension. This as per industry standards is fatal and a sure shot recipe for accidents, especially during panic situations and hence not recommended.

Two of the Swifts I am aware of, had their suspension replaced between 40K and 60K , perhaps not unusual.

These test results that show 10 and 27% are in comparison to what figure? I get it that there is a huge variance between front and rear, however which vehicle was used as a baseline?

[Sutripta]

Originally Posted by CaliforniaKnight

Kindly have a look at the videos and share if you have any suggestions.

First of all without an explanation of what is being tested, how it is being tested, and how the data is being presented, must say that I am totally lost when it comes to the last graph.

Shocks can be setup to have different damping on compression and rebound.

The work of shock is damping, not to act like a spring. The fact that these gas dampers have some springlike characteristics is incidental. On an old shock it can tell the mechanic that gas has leaked. On a new shock it really tells nothing. (It is like mechanics rubbing engine oil between thumb and forefinger and pronouncing whether it is good or bad).

If you want to see if a shock goes bad, disconnect the shocks and do a bounce test. Then do the same with the shocks installed, and then come to an opinion.

One last observation: on things which can expand on their own, both ends need to be constrained (one end resting on a tiled floor will not do), and the body kept out of harms way in case the item telescopes out suddenly.)

The Gabriel system used to raise the wheel a known height and then suddenly drop it, recording displacement of body (not wheel) against time on a paper chart.

Regards
Sutripta

[CaliforniaKnight]

Originally Posted by Kosfactor

Two of the Swifts I am aware of, had their suspension replaced between 40K and 60K , perhaps not unusual.

These test results that show 10 and 27% are in comparison to what figure? I get it that there is a huge variance between front and rear, however which vehicle was used as a baseline?

Hello Kosfactor,
We have not set a baseline vehicle as such. The suspension test was carried out to see the effectiveness of the shocks, springs and other critical suspension components. The 10% and 27% indicates that the damping and rebound is not effective, suggesting worn out suspension components even though the shocks and springs are brand new.

Originally Posted by Sutripta

First of all without an explanation of what is being tested, how it is being tested, and how the data is being presented, must say that I am totally lost when it comes to the last graph.

Shocks can be setup to have different damping on compression and rebound.

The work of shock is damping, not to act like a spring. The fact that these gas dampers have some springlike characteristics is incidental. On an old shock it can tell the mechanic that gas has leaked. On a new shock it really tells nothing. (It is like mechanics rubbing engine oil between thumb and forefinger and pronouncing whether it is good or bad).

If you want to see if a shock goes bad, disconnect the shocks and do a bounce test. Then do the same with the shocks installed, and then come to an opinion.

One last observation: on things which can expand on their own, both ends need to be constrained (one end resting on a tiled floor will not do), and the body kept out of harms way in case the item telescopes out suddenly.)

The Gabriel system used to raise the wheel a known height and then suddenly drop it, recording displacement of body (not wheel) against time on a paper chart.

Regards
Sutripta

Hi Sutripta, Let me highlight my observations and in sequence answer your queries.

The suspension was tested by ST (Suspension test machine). This is a machine that tests the path of each wheel of the vehicle in 12 seconds according to the criteria determined by EUSAMA (European Shock Absorber Manufacturer Association).

To test, placing the wheel on the related platform and then pressing a key will be enough. After about 12 seconds, graphics that shows how the vehicle in various road conditions can hold the road, will appear on the screen.
As known, the main objective of the suspension system is not the comfort of the passengers; it is to provide holding the road that delivers safe travel.

The below video link from 1m:05s, is exactly how the S-cross was checked with brand new shocks and springs.

https://www.youtube.com/watch?v=MKaPjW0NWN0

Any car without shock absorbers will bounce. There is no point trying to do a bounce test without shock absorbers. Springs cannot hold energy, so when compressed they will hold energy and when released, the held energy is released. A shock absorber controls the absorption and release of energy by the spring.

A shock has to be tested upright and not lying down,since oil controls the characteristics. When the shock is not upright oil might not be circulated properly.

[Kosfactor]

Originally Posted by CaliforniaKnight

Hello Kosfactor,
We have not set a baseline vehicle as such. The suspension test was carried out to see the effectiveness of the shocks, springs and other critical suspension components. The 10% and 27% indicates that the damping and rebound is not effective, suggesting worn out suspension components even though the shocks and springs are brand new.

.

The reason I asked is to find out how different it is from a brand new SCross.

I found this online and I figure Maruti had plenty of time to correct if there was something wrong with the design. I hope 2018 model year fares better, else this maybe a case of irresponsible behaviour from the manufacturer's side.

http://overdrive.in/news-cars-auto/f...-eight-months/

[CaliforniaKnight]

Originally Posted by Kosfactor

The reason I asked is to find out how different it is from a brand new SCross.

I found this online and I figure Maruti had plenty of time to correct if there was something wrong with the design. I hope 2018 model year fares better, else this maybe a case of irresponsible behaviour from the manufacturer's side.

http://overdrive.in/news-cars-auto/f...-eight-months/

Hi Kosfactor, The Overdrive long term ownership has been cited before on the official review of the S-cross column, and a member who owns the S-cross and faced suspension problems had highlighted the same to the TSM of Maruti.

Maruti officials had brushed aside the report, and the owner's finding as inadequate and after multiple test drives, the officials found the car suspension to be performing satisfactorily.

The mistake with the Over drive diagnosis is, that the suspension on the S-cross is very long travel and there is no reason why the bump stops would hit. Either the springs are too soft or the damping is not good enough to stop the travel of the suspension from hitting the bump stops on the shocks.

The suspension travel on the rear shocks is 9 inches before it hits the bump stops. On an unladen car the suspension travel should be minimum of 6 inches.

I would also like to add that the suspension at the rear, is similar to the SX-4 and it has the same length when extended and compressed. The S-cross, it seems is an enlarged design on the suspension part of the SX-4.

[Sutripta]

Originally Posted by CaliforniaKnight

Hi Sutripta, Let me highlight my observations and in sequence answer your queries.

The suspension was tested by ST (Suspension test machine). This is a machine that tests the path of each wheel of the vehicle in 12 seconds according to the criteria determined by EUSAMA (European Shock Absorber Manufacturer Association).

To test, placing the wheel on the related platform and then pressing a key will be enough. After about 12 seconds, graphics that shows how the vehicle in various road conditions can hold the road, will appear on the screen.
As known, the main objective of the suspension system is not the comfort of the passengers; it is to provide holding the road that delivers safe travel.

The below video link from 1m:05s, is exactly how the S-cross was checked with brand new shocks and springs.

It will likely be a (perhaps modified) four post rig.
'Turnkey - viola' does not satisfy the curious.
It seems the wheel is excited at the freq mentioned (and not for 12 secs). Amplitude not mentioned. Type (trapezoidal, triangular, sinusoidal?) also not mentioned. Are all the wheels excited together, or individually? If not individually, what is the phase relationship? (For coupled wheels, it should be important).
At say 15 Hz I expect the amplitude to be small. Are the tyres part of the system (looks like they are). In which case they will play a very important part. Including the inflation pressure.

I have some idea of what the graph depict, but I could be wrong. So if you could explain in your own words, it would be helpful.

Any car without shock absorbers will bounce. There is no point trying to do a bounce test without shock absorbers. Springs cannot hold energy, so when compressed they will hold energy and when released, the held energy is released. A shock absorber controls the absorption and release of energy by the spring.

Without the shocks you get a baseline. An idea of the natural frequency (which also tells basically if the car is softly sprung, or not). Also the time for the oscillations to die down gives an idea of damping in other parts of the system.

A shock has to be tested upright and not lying down,since oil controls the characteristics. When the shock is not upright oil might not be circulated properly.

Sure. Context please.

Regards
Sutripta

[CaliforniaKnight]

Originally Posted by Sutripta

It will likely be a (perhaps modified) four post rig.
'Turnkey - viola' does not satisfy the curious.
It seems the wheel is excited at the freq mentioned (and not for 12 secs). Amplitude not mentioned. Type (trapezoidal, triangular, sinusoidal?) also not mentioned. Are all the wheels excited together, or individually? If not individually, what is the phase relationship? (For coupled wheels, it should be important).
At say 15 Hz I expect the amplitude to be small. Are the tyres part of the system (looks like they are). In which case they will play a very important part. Including the inflation pressure.

I have some idea of what the graph depict, but I could be wrong. So if you could explain in your own words, it would be helpful.


Without the shocks you get a baseline. An idea of the natural frequency (which also tells basically if the car is softly sprung, or not). Also the time for the oscillations to die down gives an idea of damping in other parts of the system.

There is a lot of information available on the internet regarding the testing practice and the test equipment. With regard to your questions even the service engineers at Maruti would not be able to answer. I am enclosing a link which discusses the practices in use.

http://iopscience.iop.org/article/10...8/1/012034/pdf

From my findings 5-15Hz is the frequency at which suspension is tested for and the amplitude can extend upto 30mm.

For any customer, its the outcome of the test thats important. How it was tested, where it was tested or the methods used for testing are irrelevant. The objective of the customer is whether the suspension is working according to the respective standards or norms.

Now, NEXA also has the same setup and the S-cross with the new rear shocks and springs, was tested privately as well as at NEXA.
At both places, the cars rear suspension results were pathetic.
The question to be asked is, how come a pair of brand new springs and shock absorbers are not performing according to the standards of NEXA service?
what about the vehicles plying on the roads with defective shock absorbers or in this case I would say suspension? What about the safety considerations of these vehicles is the question which needs to be asked.

Originally Posted by Sutripta

Sure. Context please.

http://gabriel.com/wp-content/upload...10-Priming.pdf

In the PDF, it clearly states that shocks need to be primed before being tested because shocks when shipped, the oil and gas mix with each other and cause irregular damping / rebound characteristics. Hope that clears.

[Sutripta]

The suspension (and by extention, its components) has to deal with two contradictory requirements - Ride and Handling. So when one of its (important) components is characterised by one composite figure, I for one would very much like to know how it was arrived at, what exactly it means.

It would be great if you can educate us on these matters with a few lines in your own words. Links to dozens of articles does not really help for various reasons, principally because

In your case,
Maybe the shocks in your car are defective.
Maybe a whole batch of shocks (new as well as installed) are defective.
Maybe that is how it is designed and supposed to be.

Maruti has a fairly effective escalation matrix. I'd suggest you start making use of it. Maybe Sashi can help you with it.

Regards
Sutripta

[CaliforniaKnight]

Originally Posted by Sutripta

The suspension (and by extention, its components) has to deal with two contradictory requirements - Ride and Handling. So when one of its (important) components is characterised by one composite figure, I for one would very much like to know how it was arrived at, what exactly it means.

It would be great if you can educate us on these matters with a few lines in your own words. Links to dozens of articles does not really help for various reasons, principally because

In your case,
Maybe the shocks in your car are defective.
Maybe a whole batch of shocks (new as well as installed) are defective.
Maybe that is how it is designed and supposed to be.

Maruti has a fairly effective escalation matrix. I'd suggest you start making use of it. Maybe Sashi can help you with it.

Regards
Sutripta

One member had issues and the problem was escalated to Maruti officials by NEXA. Maruti officials were not able to find any fault with the suspension because there was no oil leak, no noise, etc.
The member had asked for damping and rebound force through a mail to Maruti TSM, but they were unable to provide the requested details. The member dejected, tried contacting Maruti officials at the higher level by looking up linkedin and mailed them. Till date there has been no reply from them as well. If you do happen to know the escalation matrix, please can you PM me or post it here for the benefit of people who owns an S-cross.

The interesting thing that happened today, is that the NEXA test car failed the suspension test, at NEXA facility.



Group member from Hyderabad who did the test, barely managed to pas with 42%. The member had a doubt and decided to check the tyre air pressure and noticed it was at 28psi. He filled air, and repeated the test. Now the test result was down by 1%, which again is very much close to the border line pass mark.



Failed - S cross shocks.



NEXA's own test car fail.

[pramodbenson]

I own an S-cross 1.6 since October 2016. I did not face any issues with the suspension during my first year of ownership. It all started in early 2018 and the ride quality went from bad to worse. I can literally feel my car's rear going out of line on even small turns. It is bouncy and not at all confidence inspiring. I have taken this up with MASS and they ruled out any issues with the suspension. After reading through this thread, I am escalating this issue with my service manager. They has assured that they will do a suspension test and replace parts if the car fails their tests. Just to add, This is an excellent car with a great engine but the suspension lets it down big time.

[CaliforniaKnight]

Originally Posted by pramodbenson

I own an S-cross 1.6 since October 2016. I did not face any issues with the suspension during my first year of ownership. It all started in early 2018 and the ride quality went from bad to worse. I can literally feel my car's rear going out of line on even small turns. It is bouncy and not at all confidence inspiring. I have taken this up with MASS and they ruled out any issues with the suspension. After reading through this thread, I am escalating this issue with my service manager. They has assured that they will do a suspension test and replace parts if the car fails their tests. Just to add, This is an excellent car with a great engine but the suspension lets it down big time.

Yes, this is exactly the issue many S-cross owners are facing. When the issues is raised at NEXA, it is being brushed off stating, everything is normal.
There is an issue with the rear shock absorbers and for some unknown reason Maruti is not addressing it. Have a look at the below test result.



Another S-cross 1.3 with a failed report on the rear suspension. This is the first brand new S-cross 1.3 face lift, that underwent testing from our group.

The machine calibration cannot be under doubt, since it shows fairly good readings for the front shocks.

[Sutripta]

For escalation, drop Sashi a PM.

The online parts suppliers - what brand do they supply?

Any cobblestone (or similarly paved) roads in your vicinity? If so, could you see if the ABS activates when braking.

Not connected with the main issue, but why is shocks wont work properly if horizontal coming up in our discussion?

Regards
Sutripta