Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 12th March 2015, 11:03   #61
Distinguished - BHPian
 
saket77's Avatar
 
Join Date: Dec 2012
Location: Ranchi
Posts: 3,189
Thanked: 4,204 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by Sanjunair5 View Post
So that just makes it qualify as a coincidence - that of 5 alloys of the same design getting damaged appearing on one forum. No?
These alloys rims do not go on to vehicle straight off a foundry. They go through various destructive and non destructive tests to check for quality. And these are highly proven scientific tests.
Am I concerned as a XUV owner? No, my basic knowledge of manufacturing processes tell me that this is far from a concerning situation.
Ofcourse an OEM or Mahindra may want to investigate specific instances. But this is not a, sky has fallen down situation yet.
Dear Sanju,

Disagree with your point.

All components of all vehicles sold go through one or another quality check. Yet, recalls by manufacturers are frequent and they not only include simple & non-critical stuff like door hinges, but also critical systems like airbags and suspension systems. Had all quality checks been 100% conclusive & fool-proof, I wonder if we had to see any recalls ever.

And 5 instances of shearing off rims at the same point in an aftermarket OE fitment does rings alarm bells in head if you don't look at it just like a statistic. Even if the owners had hit a pothole at speed, then also breaking of the alloys at the same point does point to a weak link in the structure. And how often we come across breaking of OE alloys even on this forum from a single manufacturer?

A potential risk remains a risk - happening of the event does not matter. So a thorough investigation by Mahindra should be done. It will be good for both Mahindra and its customers. If the design is fine, Mahindra will come clean on it and if there is an issue, then a recall and replacement should be the norm.

Regards,
Saket

Last edited by saket77 : 12th March 2015 at 11:10.
saket77 is offline   (2) Thanks Reply With Quote
Old 12th March 2015, 11:12   #62
BHPian
 
Anandg's Avatar
 
Join Date: Mar 2010
Location: Bangalore
Posts: 293
Thanked: 15 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

This incident reminds me if similar metallurgical blunder in Titanic as well as a train accident in Germany where due to improper metal concentrations and testing in alloys, the stress caused the component to break and cause loss of life and property. Shouldn't M&M be sued in consumer forum for taking life's of people for a heavenly ride?
Anandg is offline   Reply With Quote
Old 12th March 2015, 11:33   #63
Senior - BHPian
 
Captain Slow's Avatar
 
Join Date: Mar 2010
Location: Bangalore
Posts: 1,256
Thanked: 649 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by SDP View Post
Here are the pics of the W8 stock alloy's inside:


Did not find the name of the OEM supplier anywhere.

Can you post the marking on the last to pics? (exact letters?) Trying to figure out who made these alloys.

Just because they are made in China we can not be badge as "Bad Quality or inferior"


I can see some marks on tyres? Could these be because of some kind of Impact?
XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!-upload-1.jpg

Are these alloys also Made in China ?

We are talking about Indian Pot holes here! I lost 2 steel rims thanks to our roads.

p.s
Last I heard Nasa wanted to test their next gen rover on our roads!
Attached Thumbnails
XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!-upload-21.png  

Captain Slow is offline   (3) Thanks Reply With Quote
Old 12th March 2015, 11:48   #64
Senior - BHPian
 
sourabhzen's Avatar
 
Join Date: Jun 2012
Location: GURGAON
Posts: 1,541
Thanked: 1,277 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by Captain Slow View Post
We are talking about Indian Pot holes here! I lost 2 steel rims thanks to our roads.
I agree with you.

However, Mahindra should really consider these incidents as serious safety threats and propose a solution at the earliest. Majority of XUVs have to spend their time om Indian pot holes and they must be capable to withstand the torture.
sourabhzen is offline   Reply With Quote
Old 12th March 2015, 11:53   #65
Team-BHP Support
 
Vid6639's Avatar
 
Join Date: Jul 2006
Location: Bangalore
Posts: 14,467
Thanked: 19,367 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by Sanjunair5 View Post
Vidyut, wouldnt it be nicer if sarcasm is kept out of the discussion?
My point really is five cracking alloys is still a statistically insignificant number to make any inference from. You will need at least 30 data points to think of a distribution.
So I understand your point is it is a manufacturing defect. And it is fine by me.
Though for me it is not conclusive yet.

Apologies for the sarcasm. The point I was trying to make is that alloy wheels are not the only part of the car that are tested extensively. Every component has to go through tests to and beyond the limit.

Even one case forget 5 needs to be investigated especially if it's a manufacturing defect.

Maruti is changing door locks cause the door if not closed fully can open. this is far more severe. Imagine doing 120kmph and you go over a pothole and the alloy shatters.

For me not only is it conclusive but something which I expect Mahindra to do a thorough inspection and issue a recall if needed.

5 random wheels cannot shatter under any circumstances. The DPPM of 10 is unacceptable in the industry with 100,000 XUV's on the road. Moreover not even 10% probably have these particular defective alloys. so the DPPM is even worse.
Vid6639 is offline   (8) Thanks Reply With Quote
Old 12th March 2015, 12:02   #66
Team-BHP Support
 
Rehaan's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 22,364
Thanked: 22,568 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Here's one more possible incident:
March 2012:
dear friend's my friend has purchased new xuv500 recently after having driven it for 1500 kms very carefully as it is in running in condition to his utter shock and dismay the front driver side wheel just broke off and car landed on the bumper on informing the dealer india garage bangalore in a matter of 10 hrs they came and took the car on a truck to their showroom as we live about 300 kms from bl'r for repair now it comes down to the fact that a brand new car having such a major fault and very bad quality control delivering such cars to customers who after paying so much money put their family and their lives at great risk kindly advise as to what can be done now
Source
Quote:
Originally Posted by GTO View Post
Here's another report of a damaged alloy wheel
That looks 100% like an external impact to me. Even the BHPian who posted it said:
As per him, driver was driving on a narrow and rough road (usual Indian road) ... got the left wheels off the road and applied breaks ... both him and driver heard a sound ... Santro guy stopped as he too heard some sound.
... I think it's safe to exclude this incident / wide-spoke alloy design.

Problem seems to be only with the "Sporty Speed-Rims" (shown on left), and not the Wide-Spoke design:
XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!-xuv-alloys.jpg

Quote:
Originally Posted by Gannu_1 View Post
Quite possibly bad metallurgy (quality of casting). M&M should insist the OEM (or a good third party) to do the fatigue tests of this wheel from a batch of these cars that were sold.


If it's a casting/manufacturing issue : it will probably be limited to a few batches.
If it's a design issue : it would probably be more wide-spread

Chances are its a combination of a weak point in the design (which wouldn't be an issue on it's own), combined with some casting issues.

Quote:
Originally Posted by M35 View Post
I always thought if over -tightening of wheel nuts on these brittle alloy designs could have any adverse effect ?
Absolutely something that popped into my head too. While over-tightening can't be entirely responsible for this, it could perhaps have a small part to play.

The size & positioning of the holes could certainly have a part to play in the inherent design weakness too!

Quote:
Originally Posted by humyum View Post
Very strange, Alloy wheels are something which never really break, bend yes, crack yes, but break is something unheard of.
Nope - I think it's actually the opposite.

Alloy wheels are MORE likely to break when compared to steel wheels, which will continue to bend even past that threshold.

^ That applies to cast alloys (the huge majority of wheels on our cars). Forged alloys (the high end, lighter, stronger versions) might actually be more prone to shatter when the impact received crosses their threshold.

Quote:
Originally Posted by Sanjunair5 View Post
Mahindra has sold over 100,000 XUVs, most of them with alloy rims. And in this thread I see fewer than 5 instances of cracked rims being discussed, which is a very low sample to jump to conclusions.
Question is - how many of those 100,000 XUVs had this alloy design?

Quote:
Originally Posted by venkyhere View Post
1) alloys are supposed to be "cast" as a single piece (OR) in case of ultra high end super cars - forged from a single block. Could it be that the alloy wheel supplier is cheating M&M by providing inferior multiple-cast-pieces-welded-together-into-one-wheel ?

2) are the dealers playing a game here, by swapping OEM alloys with aftermarket duplicate ones before handing over the car to the customer, and making a few bucks on the sly ?
1) Nope. Extremely unlikely.
2) Nope. Extremely unlikely.

It's probably a quality control issue, and nothing more convoluted than that.

Quote:
Originally Posted by Sanjunair5 View Post
Ofcourse an OEM or Mahindra may want to investigate specific instances. But this is not a, sky has fallen down situation yet.
Exactly, and that's why this thread exists - to bring that to light.

I agree with you that we shouldn't jump to conclusions, however, I also think there is a pattern here.

Think of it this way, can you even find 1 picture of any other Indian car where the alloy has broken just like this (at low speed with no claim of impact).

It's a unique type of break that points to a weakness in the design or manufacture of the wheels.

Quote:
Originally Posted by raj_5004 View Post
The OE wheels which come with the W8 should be kept out of this discussion. One crack in a particular vehicle does not say anything. We have no idea under what circumstances it broke.
Agreed, it will probably cause unnecessary confusion / paranoia with the XUV owners reading this thread.

Quote:
Originally Posted by raj_5004 View Post
  1. Hold the sale of these "speed" rims for the moment
  2. A simply investigation of these 5 incidents - where these from the same batch?
  3. If they were from the same batch, maybe that batch was faulty.
  4. If they are not from the same batch, maybe there is a design issue with these rims or even serious - the manufacturer lacks serious quality control. In both cases, Mahindra should just stop sourcing these rims from them.
^ + 1000000

EXCELLENT point about it probably just being 1 batch.

Quote:
Originally Posted by Captain Slow View Post
I can see some marks on tyres? Could these be because of some kind of Impact?
That doesn't look like an impact to me.

Looks like the wheel slid on the road a bit, before rotating some more and coming to a rest.

Last edited by Rehaan : 12th March 2015 at 12:23.
Rehaan is offline   (11) Thanks Reply With Quote
Old 12th March 2015, 12:13   #67
SDP
Team-BHP Support
 
SDP's Avatar
 
Join Date: Jan 2010
Location: Mumbai
Posts: 3,703
Thanked: 7,599 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by Captain Slow View Post
Can you post the marking on the last to pics? (exact letters?) Trying to figure out who made these alloys.
...
The inside was quite dirty and even after cleaning with a toothbrush, I couldn't get the lettering any cleaner than what the pics show. I have hi-res pics at home. Let me try to figure out the letters later tonight.

Quote:
Just because they are made in China we can not be badge as "Bad Quality or inferior"
Precisely the reason, why I have not mentioned anything more about the "Made in China" markings besides they being there. What quality you get from China depends on what design, material and tolerance specifications you have given.

The whole point of posting the markings was to rule out Indian OEMs like Neo which was mentioned.

Quote:
Are these alloys also Made in China ?
We will have to request some owner with these alloys to take pics similar to mine. Only then we can figure out where they are made and who is the OEM.


Quote:
I can see some marks on tyres? Could these be because of some kind of Impact?
With all due respect, somehow I don't think so. Check the same pic with additional areas marked in blue and white.
XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!-broken-alloy-5.jpg

The blue area shows that the skirting of the wheel arch has been dislodged. The white area on the right shows that even the fender has been damaged and the black skirting has folded inside. In my opinion, all this damage to the skirting and fender has been done after the alloy broke and the tyre came in contact with the skirting and fender. So the dirt mark on the tyre is most likely because of the tyre touching the inner side of the skirting.

Just my theory. Except the owner, nobody really knows what exactly happened.

Last edited by SDP : 12th March 2015 at 12:16.
SDP is offline   (3) Thanks Reply With Quote
Old 12th March 2015, 12:20   #68
Team-BHP Support
 
Rehaan's Avatar
 
Join Date: Feb 2004
Location: Bombay
Posts: 22,364
Thanked: 22,568 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by Vid6639 View Post
5 random wheels cannot shatter under any circumstances.
Vid, where are you getting this "5" number from?

I can only see 2 incidents of the speed-rim design in this thread (with pics), as well as a the 1 additional mention (rim style unknown) that I've shared in my post above...
Rehaan is offline   Reply With Quote
Old 12th March 2015, 12:29   #69
SDP
Team-BHP Support
 
SDP's Avatar
 
Join Date: Jan 2010
Location: Mumbai
Posts: 3,703
Thanked: 7,599 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by Rehaan View Post
Vid, where are you getting this "5" number from?

I can only see 2 incidents of the speed-rim design in this thread (with pics), as well as a the 1 additional mention (rim style unknown) that I've shared in my post above...
Was going to say just that!
Had started reading the thread once again with a fine comb just to be doubly sure before contradicting a mod
SDP is offline   Reply With Quote
Old 12th March 2015, 12:30   #70
Senior - BHPian
 
abhishek46's Avatar
 
Join Date: Oct 2010
Location: Bangalore
Posts: 1,023
Thanked: 1,907 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

This looks like a serious quality issue and potentially very dangerous.
Aren't alloy wheels supposed to be stronger than ordinary steel wheels? Good quality alloys are so sturdy that they dont need alignment even after years of rough use.

Alloys wheels breaking, that too at such low odo reading is schocking, it is a serious quality issue probably compounded by the alloy design.
abhishek46 is offline   Reply With Quote
Old 12th March 2015, 12:36   #71
Team-BHP Support
 
Vid6639's Avatar
 
Join Date: Jul 2006
Location: Bangalore
Posts: 14,467
Thanked: 19,367 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by Rehaan View Post
Vid, where are you getting this "5" number from?

I can only see 2 incidents of the speed-rim design in this thread (with pics), as well as a the 1 additional mention (rim style unknown) that I've shared in my post above...
Quote:
Originally Posted by SDP View Post
Was going to say just that!
Had started reading the thread once again with a fine comb just to be doubly sure before contradicting a mod
Dammit. Rare goof up.

I misinterpreted this post:

Quote:
Originally Posted by Sanjunair5 View Post
Folks, I think many here are jumping to hasty conclusions. Mahindra has sold over 100,000 XUVs, most of them with alloy rims. And in this thread I see fewer than 5 instances of cracked rims being discussed, which is a very low sample to jump to conclusions.

Granted, alloys can crack due to manufacturing defects, but can also crack due to other issues like hitting an obstacle hard, wrongly centered rim etc.
In any case the number of speed alloys wheels is much smaller so the 2-3 cases itself is very high DPPM.

I think Rehaan has summed up what I was saying in a much better way.
Vid6639 is offline   (3) Thanks Reply With Quote
Old 12th March 2015, 13:58   #72
M35
BHPian
 
M35's Avatar
 
Join Date: Dec 2012
Location: KL 9
Posts: 601
Thanked: 1,252 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by Rehaan View Post
Problem seems to be only with the "Sporty Speed-Rims" (shown on left), and not the Wide-Spoke design:
Attachment 1348913
They should have had those OE alloys on the test mules at the development stage and tested on Indian roads but probably not those ‘sporty speed-rim alloys’, hence the need for a thorough investigation.
M35 is offline   Reply With Quote
Old 12th March 2015, 14:15   #73
BHPian
 
amoghchaphalkar's Avatar
 
Join Date: May 2009
Location: Pune
Posts: 554
Thanked: 248 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Quote:
Originally Posted by Sanjunair5 View Post
My point really is five cracking alloys is still a statistically insignificant number to make any inference from.
By that yardstick - ownership reviews (good and bad) on the forum are also statistically insignificant. Just look at the ratio of number of reviews for a model vis a vis the number sold. Are they?

There might be 30 data points already. Just because we do not know about the other does not make the reported incidents insignificant.

But irrespective of that, for a product manufacturer, no customer is statistically insignificant. In all probability this is one batch of faulty alloys. An investigation from M&M is definitely warranted.

Last edited by amoghchaphalkar : 12th March 2015 at 14:19.
amoghchaphalkar is offline   Reply With Quote
Old 12th March 2015, 15:33   #74
BHPian
 
Join Date: Feb 2012
Location: Pune
Posts: 286
Thanked: 268 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

What can be the possibilities of failure for alloy wheels

Considering that for all SUVs the norm is that you should drive moderately fast through bad patches and the ride is more comfortable as compared to driving slowly through them.

Now having marketed this, it becomes highly important that limitations of the product need to be understood before using it likewise.

What is moderately fast for me, would be slow for someone else, each one has a different yardstick.

Since the main stress element for alloys is bang on in the center, all the impact sustained by the tyres is directly transferred to the hub. Low tyre pressure and a bad hit with a stone/divider etc can cause structural failure. This maybe immediate or maybe over a period of time of similar abuse weakens the hub significantly for it to break eventually.
But in the case of SUVs where the product is marketed specifically for its ability to take on abuse, such critical components should have significantly higher tolerance levels as compared to regular alloy wheels.

Now, definitely an investigation should be made with all due respect, ideally such investigations should be conducted by 3rd party or Government institutions or governed by similar principles like crash testing.

Statistics can be highly misleading and should not be used as a point of argument especially where there is a high risk of fatalities. A death is a death whether one or many, now the lucky occupants of the cars got away without anything major, but I think even the passers-by and the vehicles in the opposite direction were lucky, this could have easily turned catastrophic.

Cheers!
Trojan is offline   Reply With Quote
Old 12th March 2015, 15:34   #75
BHPian
 
Wanderers's Avatar
 
Join Date: Apr 2014
Location: Delhi-NCR
Posts: 480
Thanked: 607 Times
Default re: XUV500 safety issue: Weak alloy wheels. EDIT: Mahindra starts silent recall!

Hi

I am trying to analyze the reasons for failure of alloys. Even we own XUV500 W8, which are fitted with OEM alloys.

Here is my thought.

Typically Aluminium alloy rims are made either by die casting or by forging process.

While the castings is usually single piece, under forging process, we can have either single piece construction or multiple piece construction, which are welded together to form the rim. Most commonly we have three piece construction- front, back and center rim on which the Tyre sits.

Forgings is most common manufacturing process for alloys due to flexibility in providing the desired shape and finish. Also they are stronger but a bit costlier.

In both the cases of broken wheels, the construction is a forging based. However they have used multiple piece construction and the crack seems to propagate from welded portion.
It need not be exactly from the weld as in 1st two cases. Heat due to weld affects the adjoining area called HAZ (Heat Affected Zone), and they are more prone to cracking than the actual weld itself.

In the third case the crack is also from the welded area but it did not propagate to longer distance.

M&M need to re-design the alloys after analyzing the stress areas.

I am sure they must be using CFD (Computational Fluid Dynamics) Analysis or other Finite Element Analysis to model the alloys and calculate various parameters including stress & other forces acting during motion. Unfortunately it all depends on experience of designer and there are no clear cut guidelines or code.

Last edited by Wanderers : 12th March 2015 at 15:36.
Wanderers is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Alloy Wheels - Sai Mag Wheels (Rama Road Industrial Area) tsk13 Delhi NCR 37 30th December 2016 17:07
Weak Hyundai i20 air-conditioner. EDIT : Test results on pg. 4 agm Technical Stuff 253 11th October 2013 08:31
Received a copy of the Coffee Table book on the Mahindra XUV500 from Mahindra Corp. shankar.balan Shifting gears 3 2nd April 2012 16:26
Maverick's Silent Assassin - Hyundai Elantra CRDi! Edit: Now Filtered and Pete'd maverick030581 Test-Drives & Initial Ownership Reports 86 5th August 2010 16:58
Class Starts Early; Indigo CS launched; starts at 3.79lac jkdas The Indian Car Scene 208 28th May 2008 18:53


All times are GMT +5.5. The time now is 05:03.

Copyright ©2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks