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Old 9th June 2014, 02:32   #1
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Gearbox failure in a 10-day old Mahindra Thar

Dear All,

Hi, I’ve recently bought a Thar 10 days back. Have driven it for around 300 kms so far and was faced with a BIG problem today.

Had gone to a friends place in the evening and when I was about to leave, I sat and started the engine, put the 1st gear and as soon as I released the clutch(it happened a little quickly than usual and there was a slight jerk and a thud sound from below) and the Thar did not move as if still in neutral. I immediately pressed the clutch again and checked if the gear was properly engaged and to my horror it was (properly engaged).

Then I turned off the engine and shifted the 4wd lever from 2H to 4H and again tried to move the car but nothing. Then tried all the combinations and the reverse and the jeep was behaving as if in Neutral all this while. The gears were shifting in to their proper place but on releasing the clutch there was no action.
Couldn’t figure out the problem.

Finally parked the jeep at friends place and called up the ASC.
The ASC will get it picked tomorrow morning and let me know what the problem is.

Very Very disappointed with such an issue in a 10 day old Thar .
Guys please help.

Thanx.
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Old 9th June 2014, 11:01   #2
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Re: My li'l Red Mahindra Thar with some practical modifications

Could it be that there is a problem in the transfer case?
It must've shifted to neutral and is not engaging after that.
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Old 9th June 2014, 11:19   #3
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Re: My li'l Red Mahindra Thar with some practical modifications

Quote:
Originally Posted by starter View Post
Could it be that there is a problem in the transfer case?
It must've shifted to neutral and is not engaging after that.
Dear Starter,

Still dont know if its the transfer case or something else.

Just had a word with the service engineer @ JKAK Mahindra (Meerut ASC) they are suspecting it to be the clutch.
Getting the jeep towed now, will be able to pinpoint the problem once it reaches the workshop.
Will post asa we find out.

Thanx.
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Old 9th June 2014, 15:51   #4
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Re: My li'l Red Mahindra Thar with some practical modifications

It is a gear box problems, the pinion has slipped. Go to the ASC check the work being done and post pictures here.
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Old 9th June 2014, 18:44   #5
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Re: My li'l Red Mahindra Thar with some practical modifications

Quote:
Originally Posted by starter View Post
Could it be that there is a problem in the transfer case?
It must've shifted to neutral and is not engaging after that.
Quote:
Originally Posted by desertfox View Post
It is a gear box problems, the pinion has slipped. Go to the ASC check the work being done and post pictures here.

Dear desert fox,

Thanx for your reply.
Kindly give a little more details as to where is the pinion located.

Was at the ASC since morning. Have managed to get the gear box out.
Have clicked a few snaps, will upload asa I'm done editing them.
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Old 9th June 2014, 21:16   #6
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Re: My li'l Red Mahindra Thar with some practical modifications

Dear All,

After yesterday's fiasco of my 10 day old Thar’s gear getting disengaged, had to get it towed to the ASC this morning.

The jeep was not moving in any gear although all the gears were going into their respective slots (both the main gear and the transfer case). The jeep was behaving as though the transfer case had been put in neutral, stationary in every combination.

Spent the entire day at Mahindra ASC.

Nobody there had a clue as to what could have gone wrong, so they decided to go step by step:

1. Clutch Plate
2. Main Gear Box
3. Transfer Case

The Mahindra Dealership here is owned by a friend and so I could manage to get some work done today itself. Although they could only remove the entire gear box in about 4 hours. Once they removed the gear box, the clutch plate and the pressure plate were found to be okay.

Gearbox failure in a 10-day old Mahindra Thar-gear-box-side.jpg

Pls refer to the above pic, as explained to me by the service engineer at the ASC - now if we put the gear lever in lets say 1st gear and rotate the input drive shaft manually then the rear wheel output shaft is supposed to rotate (4x4 lever being in 2H). In this case the rear wheel output shaft was stationary.

So then they went about it the other way round.
They put the 4x4 lever in 4H and manually rotated the Front wheel drive shaft that as a result rotated the rear wheel output shaft but the input drive shaft was still stationary.

So what they have summed up is that the transfer case seems to be okay and the problem lies in the main gear assembly or the link between it and the transfer case.
They plan to open it up tomorrow and find out.

Guys pls let me know if you think that these guys are going in the right direction or if there is something that they are missing.

It has been heart breaking to see my 10 day old jeep’s gear box being taken out .

Got so many things going on in my mind right now – is this a minor defect or a manufacturing defect. Don’t know if at all I should get it repaired or just straight away ask them for a replacement…..??

Regards,
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Old 9th June 2014, 22:22   #7
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Re: My li'l Red Mahindra Thar with some practical modifications

Posting a few pics of the Thar gearbox that I'd clicked today. Kindly feel free to correct if I have marked anything wrongly.

Gearbox failure in a 10-day old Mahindra Thar-gear-box-side.jpg

Gearbox failure in a 10-day old Mahindra Thar-gear-box-top.jpg

Gearbox failure in a 10-day old Mahindra Thar-gear-box-top-rear.jpg

Gearbox failure in a 10-day old Mahindra Thar-gear-box-front.jpg

Gearbox failure in a 10-day old Mahindra Thar-gear-box-fr-close-up.jpg

Gearbox failure in a 10-day old Mahindra Thar-gear-box-rear.jpg
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Old 10th June 2014, 09:49   #8
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Re: My li'l Red Mahindra Thar with some practical modifications

So sad to hear that Namo!! Brand new Thar with the gearbox out is not a pretty sight. Thanks for the pictures though. They may help other guys in distress. Don't let them repair anything if it's anything other than something very minor. Ask for a replacement.
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Old 10th June 2014, 11:45   #9
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So sad to hear of your predicament. Seems to be a peculiar problem. Haven't come across any one else having the same issue. The approach followed by ASC seems to be okay. Is the input shaft of the gearbox freely rotating in all gears or only in neutral. Anyways more will be revealed once the GB is opened. I would suggest you closely monitor what is being done and in case of any premature failure of any part insist on full GB and/or Transfer case replacement under warranty. Nice pics posted.
Dhabhar Sir, can we please discuss the issue and your suggestions on the open forum here.

Quote:
Originally Posted by vijaytiwari View Post
Hi Samwagon , finally got my suspension arm and Bump ons separated with reasonable distance in between, from the compression and dent on one you will notice how uneven the torsion bar was set in factory fitted new Thar, thanks for the input. intact the ride quality seems better or it is my perception.
You seem to have used different bumpstops on each side. It is recommended to have them to be same type or at least same height. Please correct at earliest by grinding away the bigger one to height of the smaller one.

Last edited by moralfibre : 29th July 2014 at 07:21. Reason: Back to back posts
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Old 7th July 2014, 20:06   #10
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Re: My li'l Red Mahindra Thar with some practical modifications

Hello All,

…….continuing with the predicament I was faced with.

(BTW my jeep is now fixed and back …..)

As I understood it, the main gear box is placed in 2 housings.
The first housing (just behind the clutch assembly), houses gear 1 to gear 4 and the second one (attached right behind the first one and directly attached to the transfer case) houses the 5th and the reverse gear.

So on opening up the gear box the very next day, the main drive shaft was found broken. YEAH BROKEN INTO 2 PIECES, SNAPPED!

It was the first time that the ASC mechanics had either seen or heard of a broken drive shaft and that too in a 10 day old jeep.

As the only thing that could have amounted to such a disaster is a manufacturing defect, so I was looking at nothing else but a total replacement of the gear box.

Kindly refer to the pics below -
Attached Thumbnails
Gearbox failure in a 10-day old Mahindra Thar-thar-gb-inside-1.jpg  

Gearbox failure in a 10-day old Mahindra Thar-thar-gb-inside-2.jpg  

Gearbox failure in a 10-day old Mahindra Thar-thar-gb-inside-3.jpg  

Gearbox failure in a 10-day old Mahindra Thar-thar-gb-inside-4.jpg  

Gearbox failure in a 10-day old Mahindra Thar-thar-gb-inside-7.jpg  

Gearbox failure in a 10-day old Mahindra Thar-thar-gb-inside-8.jpg  

Gearbox failure in a 10-day old Mahindra Thar-thar-gb-inside-9.jpg  

Gearbox failure in a 10-day old Mahindra Thar-thar-gb-inside-10.jpg  

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Old 7th July 2014, 20:49   #11
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Re: My li'l Red Mahindra Thar with some practical modifications

Very very rare occurance indeed in a 10 day old Thar.

I am not sure about Mahindra Quality control, although it is manufactured by someone else.

If the entire assembly is ISUZU on all Thars then Isuzu is a world class manufacturer.

What did the ASC service supervisor tell you ? Was the oil level optimal in the gear box ?

Why did it snap ?

What will be replaced under warranty ? The entire gear box or just a new shaft and the gear box will be reassembled.

I guess you should demand complete gearbox replacement.
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Old 7th July 2014, 21:58   #12
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Re: My li'l Red Mahindra Thar with some practical modifications

Quote:
Originally Posted by desertfox View Post
Very very rare occurance indeed in a 10 day old Thar.
Yes it was indeed a one off case, esp. on a 10 day old and only 250kms driven Thar.

Quote:
Originally Posted by desertfox View Post
I am not sure about Mahindra Quality control, although it is manufactured by someone else.

If the entire assembly is ISUZU on all Thars then Isuzu is a world class manufacturer.
Well, this most certainly is a manufacturing defect, which raises serious questions about Mahindra Quality Control.
Don’t know if the entire assembly is ISUZU or its just the transfer case.


Quote:
Originally Posted by desertfox View Post
Was the oil level optimal in the gear box ?
Yes I had checked the oil level. It was full.

Quote:
Originally Posted by desertfox View Post
What will be replaced under warranty ? The entire gear box or just a new shaft and the gear box will be reassembled.

I guess you should demand complete gearbox replacement.

Must praise the Mahindra ASC and the customer care for replacing the entire gear box without any talks of replacing just the shaft and then assembling the gear box here (which I would have never agreed to anyways).
The approval for the new gearbox came within a day. It took around a week for the new gear box to reach Meerut from Nasik.
Got a call from the ASC on the 24th of June that the new gear box has arrived and they asked me to come and have a look before they fitted it. Once I did that, the jeep was fitted with the new gear box and delivered the very next day, Not a penny charged.

Attaching a few pics of the new gear box.
Attached Thumbnails
Gearbox failure in a 10-day old Mahindra Thar-20140622_181553.jpg  

Gearbox failure in a 10-day old Mahindra Thar-20140622_181604.jpg  

Gearbox failure in a 10-day old Mahindra Thar-20140622_181621.jpg  

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Old 8th July 2014, 00:16   #13
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Re: My li'l Red Mahindra Thar with some practical modifications

Quote:
Originally Posted by samwagon View Post
Hi, i think you mean bumpstops. ................... And dont forget to straighten the dent in the mount before you install new bumpstops.
Quote:
Originally Posted by vijaytiwari View Post
The process of setting the torsion bar was same as explained by Samwagon.....................and yes they didn't charge for the work.
Quote:
Originally Posted by PreethamB View Post
My Thar, which was bought new a month ago, had the same problem.................. He claims to have obtained the measurements from the Mahindra factory itself.
Dear Samwagon and everyone else with bump stop problem……guess what, the upper arms on my jeep are also ‘happily’ resting on the bump stops .

Pls refer to the pics below-

Gearbox failure in a 10-day old Mahindra Thar-lhs-bumpstop-1.jpg

Gearbox failure in a 10-day old Mahindra Thar-lhs-bumpstop-2.jpg

Gearbox failure in a 10-day old Mahindra Thar-rhs-bumpstop.jpg


The ASC here has no clue about the bump stops or how to adjust the torsion bar . Will have the torsion bar adjusted as specified by Samwagon a few posts earlier.

Also the RHS front wheel of my jeep is leaning towards the outside from the top. To my understanding that is a ‘positive’ camber.

Dunno if the ASC will be able to correct that.

Guys pls let me know if there is anything in particular that needs to be taken care off while adjusting the torsion bar and the Camber.

@Samwagon – Bro sorry for hijacking your thread.

Thanx.
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Old 8th July 2014, 10:05   #14
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Re: My li'l Red Mahindra Thar with some practical modifications

Come here to Gurgaon I will get your Torsion bar adjusted at the ASC RR Auto to perfection. Should be a maximum of 1 Hr job.

There are good mechanics here and with all this off roading from NIOC Jeepers and at least three other groups locally, these guys have become kind of Thar specialists.

I make them read all Thar posts on team bhp to increse their knowledge base.

Now A Thar Lounge is being created for monthly offline meetings and a specialist Thar modification shop is to be created by october 14.

Last edited by desertfox : 8th July 2014 at 10:08.
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Old 8th July 2014, 11:40   #15
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Re: My li'l Red Mahindra Thar with some practical modifications

Quote:
Originally Posted by NamoJain View Post
The ASC here has no clue about the bump stops or how to adjust the torsion bar . Will have the torsion bar adjusted as specified by Samwagon a few posts earlier.

Also the RHS front wheel of my jeep is leaning towards the outside from the top. To my understanding that is a ‘positive’ camber.

Dunno if the ASC will be able to correct that.

Guys pls let me know if there is anything in particular that needs to be taken care off while adjusting the torsion bar and the Camber.

@Samwagon – Bro sorry for hijacking your thread.

Thanx.
Hey NamoJain,

I have indeed observed that most of the Thars that have incorrectly adjusted torsion bar, invariably display a higher degree of "positive" camber on the front wheels. Once the torsion bar has been adjusted properly, please make sure that the wheels are aligned all over again. Please make sure that Camber, Caster and Toe are all adjusted to be within the reference range. Please do note that once the alignment is done you should still be left with a little bit of positive camber and not zero camber.

Hope it helps,
Preetham
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