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Old 16th April 2012, 20:36   #76
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

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Originally Posted by 1100D View Post
The diff locks up when there is a 100rpm difference between the right and left wheels, a cam arrangement, a reaction block, a ramping plate all of these add up to create the lock. The lock releases once you reach around 25-30 kmph (not sure about the exact speed though).
Hi,
Am sure all this is explained in the sales literature, and borne out by trying to understand the video clip. But the same video clip seems to suggest that there is more to it than that.Hence the question.

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Sutripta
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Old 16th April 2012, 22:54   #77
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

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Originally Posted by Sutripta View Post
Hi,
Am sure all this is explained in the sales literature, and borne out by trying to understand the video clip. But the same video clip seems to suggest that there is more to it than that.Hence the question.

Regards
Sutripta
Did not have the benefit of going through any sales literature, of either the vehicle or the product.

What I did get is, courtesy Uday Bhan Singh, an opportunity to participate in Eaton India's roadshow. Wherein, this specific locker mechanism was explained in detail over a cutaway section and videos. It was a demo of this plus that of the e-locker. E-locker was something that I really wanted, however isn't offerred standard on any Mahindra models.

You can check the post no 65 for a graphic representation of how it works.
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Old 16th April 2012, 23:41   #78
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

I am yet to get my cellphone back. However have received 2 images. Posting them now.

Sorry for the camera shake, the lighting condition was bad and this was on the cellphone cam

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-10042012602.jpg

The cam gear that activates the locking arrangement

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-10042012610.jpg

Will post the other pics tomorrow.
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Old 17th April 2012, 09:36   #79
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

The MLocker works on the principle of centrifugal force. There are flyweights that are pre tensioned to open out when there is a speed difference of 100 rpm between the wheels. The flyweights open out and latch on the wedge / latch as shown which locks the whole unit.

Once the vehicle crosses around 20kmph, the other end of the wedge / latch opens out on centrifugal force unlocking the differential.
Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-mlocker.jpg

Last edited by fiat_tarun : 17th April 2012 at 09:49.
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Old 17th April 2012, 13:32   #80
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

Thanks for labeling this. The explanation is also good

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Originally Posted by fiat_tarun View Post
The MLocker works on the principle of centrifugal force. There are flyweights that are pre tensioned to open out when there is a speed difference of 100 rpm between the wheels. The flyweights open out and latch on the wedge / latch as shown


However this is the only place where its a little different

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Originally Posted by fiat_tarun View Post

which locks the whole unit.
The cam (containing the flyweights) is stopped from rotating, hence the ramping plate, toothed and geared with cam gear cannot rotate anymore, hence it pushes itself out (due to the ramps) against the side gears.

As it pushes itself out, it presses against the housing, and the sidegear presses against the reaction block (center), which inturn presses against the side gear on the opposite side, which presses against the already tensed housing (but on the opposite side). Together, this forms a cohesive unit. This obtaining the lock.
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Old 17th April 2012, 13:49   #81
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

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Originally Posted by 1100D View Post
The cam (containing the flyweights) is stopped from rotating, hence the ramping plate, toothed and geared with cam gear cannot rotate anymore, hence it pushes itself out (due to the ramps) against the side gears.

As it pushes itself out, it presses against the housing, and the sidegear presses against the reaction block (center), which inturn presses against the side gear on the opposite side, which presses against the already tensed housing (but on the opposite side). Together, this forms a cohesive unit. This obtaining the lock.
Thank you 1100D. I actually work for the company that makes this. . Behind the side gear we use friction discs as well which help develop the torque to lock the unit.
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Old 17th April 2012, 13:54   #82
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

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Originally Posted by fiat_tarun View Post
Thank you 1100D. I actually work for the company that makes this. . Behind the side gear we use friction discs as well which help develop the torque to lock the unit.
Absolutely! I did not mention the friction discs just to reduce the number of components we were speaking about. However these are essential components of the orchestra as the ramping plate (and the side gear on the opposite side) presses against the housing, causing it to actually rotate with the help of these friction disks, otherwise there would be tremendous, metal to metal abrasion.
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Old 17th April 2012, 21:57   #83
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

Quote:
Originally Posted by Sutripta View Post
Hi,
Am sure all this is explained in the sales literature, and borne out by trying to understand the video clip. But the same video clip seems to suggest that there is more to it than that. Hence the question.

Regards
Sutripta
By video clip, I was referring to

Quote:
Originally Posted by 1100D View Post

You can check the post no 65 for a graphic representation of how it works.
And if one goes through it, I (my understanding. Pls. correct where necessary) see that
there are two (speed differential sensitive) bobweights. A +ve speed differential causes one bobweight to engage the actuating arm, -ve speed differential the other bobweight.

Once activated, lockup is a caused by the relative movements of the cam plates (the ramps). The ramps are symmetric, and which ramp is in action is a function of which wheel is transferring torque to the other wheel.

Thus if one goes from +ve to -ve speed differential (or vice versa), the ramps in use will differ, as will the effective bobweight. In my mind, this means that the system will disengage, and reengage.

Thus my question
Quote:
Originally Posted by Sutripta View Post
From the explanation, it looks like when you go in reverse to autolock the diff, and then go forward, it will unlock and then relock. Is that correct?
which is not answered by
Quote:
Originally Posted by 1100D View Post
The diff locks up when there is a 100rpm difference between the right and left wheels, a cam arrangement, a reaction block, a ramping plate all of these add up to create the lock. The lock releases once you reach around 25-30 kmph (not sure about the exact speed though).
Regards
Sutripta
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Old 17th April 2012, 22:42   #84
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

Quote:
Originally Posted by Sutripta View Post
Hi,
Am sure all this is explained in the sales literature, and borne out by trying to understand the video clip. But the same video clip seems to suggest that there is more to it than that.Hence the question.
Dada, see if this video answers your query. If you have more questions, I think Tarun will be the right guy to answer them.



Spike
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Old 17th April 2012, 23:19   #85
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

Quote:
Originally Posted by Sutripta View Post
By video clip, I was referring to


And if one goes through it, I (my understanding. Pls. correct where necessary) see that

Yes, you are right on this.

only 1 of the side gears have cam ramps

This arrangement is present in only 1 side

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-pic-1.jpg


Here is how the side gear and camplate is oriented in unlocked condition ("a" indicates the position of 1 fixed point on the cam plate)

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-pic-11.jpg



Say on a positive differential, the cam plate ramps up like this (Note the position of the same point "a" ) - creating locking as the cam plate slides out and presses against the friction pads against the housing, the side gear presses against the central reaction block, which in turn presses against the "normal" side gear on the opposite side, which also pushes against the friction pads on that side, and then the housing. In all everything in the axis of the rear axle, is pressed tightly against each other.

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-pic-2.jpg


Then on a negative differential the cam plate will ramp up the other way (note position of same point "a") - the effect is same

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-pic-3.jpg




Quote:
Originally Posted by Sutripta View Post
Thus if one goes from +ve to -ve speed differential (or vice versa), the ramps in use will differ, as will the effective bobweight. In my mind, this means that the system will disengage, and reengage.

Thus my question

which is not answered by


Regards
Sutripta
Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-pic-5.jpg

Thus, in the same arrangement, the movement of the cam plate is caused by restriction of the shaft thats connected to both the ends, and thus rotating at a differential rpm between left and right. The restriction is caused, when the centrifugal force acting on the flyweights move it outwards and the paw engages with the latch on the "lock out mechanism"

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-pic-4.jpg

Once actuated, its only released when the "lock-out mechanism" is forced to rotate on its own shaft. This happens when the centrifugal force acting on its bottom weight causes its paw to move away. This happens when the entire housing has reached a preset rotational velocity.

Not sure if this answers!!
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Old 18th April 2012, 20:29   #86
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

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Originally Posted by SPIKE ARRESTOR View Post
Dada, see if this video answers your query.
Thanks. But essentially same as the other clip, but in colour. No added information (other than the detent about 0 speed diff).

Quote:
Originally Posted by 1100D View Post
Yes, you are right on this.
.....
Not sure if this answers!!
So, considering you have the vehicle at hand, the easiest thing would be to check it out.

Regards
Sutripta
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Old 18th April 2012, 23:09   #87
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

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Originally Posted by Sutripta View Post
Thanks. But essentially same as the other clip, but in colour. No added information (other than the detent about 0 speed diff).


So, considering you have the vehicle at hand, the easiest thing would be to check it out.

Regards
Sutripta

Sure feel free to try it out. Let me know a day in advance, I will make sure, I have Marengo with me that day. There are couple of locales at Rajarhat that can allow activation of the MLD

Some more pics from the install

The packaging

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-10042012607.jpg

A few more pics of the device

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-10042012612.jpg

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-10042012613.jpg

This needs to come out

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-10042012616.jpg

But not before this did (SCORPIO - No doubt)

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-10042012615.jpg

The hub, without the axle

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-10042012617.jpg

This is the only area where we faced issues. The stock bolts (10) that held the crown plate to the stock diff assembly, were found longer when affixed to the MLD unit. The stock diff unit has the crown plate bolted to both the flange as well as the cover plate, hence the bolt needs to be longer, whereas on the MLD its just the flange.

The workshop could not find suitable bolts, in the end, the cut 10 stock bolts to size and then milling/threading them to affix the crown plate.

Was a little tensed if the position of the flange was different, but then, on putting back, it all fell in exact place. So all is fine.

Marengo: Rocky Beige Mahindra Scorpio mHawk 4WD & MLD. 4 years & 1 lakh kms up!-10042012619.jpg
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Old 19th April 2012, 20:43   #88
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

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Sure feel free to try it out. Let me know a day in advance, I will make sure, I have Marengo with me that day. There are couple of locales at Rajarhat that can allow activation of the MLD
No need for that! Just jack up the rear wheels and check.

Quote:
The workshop could not find suitable bolts, in the end, the cut 10 stock bolts to size and then milling/threading them to affix the crown plate.

Was a little tensed if the position of the flange was different, but then, on putting back, it all fell in exact place. So all is fine.
I hope they know how to set up a hypoid.

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Sutripta
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Old 19th April 2012, 20:57   #89
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

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Originally Posted by Sutripta View Post
No need for that! Just jack up the rear wheels and check.


I hope they know how to set up a hypoid.

Regards
Sutripta

Had done just that at the workshop itself, right after the install, demonstrating to the mechanics what they have worked on. They know very well that on usual scorpios, they can hold on to one rear wheel, while the vehicle is hoisted and is idling in-gear.

On this one, after the spinning wheel reaches a certain rpm (after revving a bit) the held wheel, locks and breaks free from the hand!!

The workshop is the Mahindra workshop, setting up of the hypoid gears (although they dont know it by this name!!), backlash adjustment they do as a routine (they just follow a SOP!)

The vehicle has been running absolutely fine ever since, no humming grinding, through the entire speed range.

Last edited by 1100D : 19th April 2012 at 20:58.
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Old 19th April 2012, 21:02   #90
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Default Re: Marengo- Rocky Beige Scorpio mHawk 4WD- Only one in India till now (Updated with

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On this one, after the spinning wheel reaches a certain rpm (after revving a bit) the held wheel, locks and breaks free from the hand!!
Checking not the locking part, but the unlocking/ relocking part.

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Sutripta
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