[Vikram Arya]

Originally Posted by MithunSathianat

For earlier Thar's, there was MLD + BLD on the rear axle. It was just for cost cutting and increasing profit margins M&M decided to take away with MLD.
If one really needs MLD, this can be fitted at an extra cost.

Can you please explain why MLD cannot be offered on front axle?
Is it not possible to add MLD in front axle of Thar like rear?

The Front axle of a 4X4 can be equipped with a manual locking differential however there are some added complexities in the case of Thar that make it a challenging scenario.

First, the suspension of Thar is an independent setup with CV joints and not a solid axle. Stories of drive shafts popping out of CV joints abound on global 4X4 forums especially when they have MLDs on the front axle.

Second, the moment you equip the front axle with MLD's it will be very difficult for the driver to steer the vehicle as both the front drive shafts are locked and we know that the basic requirement of a vehicle when going around a curve is its ability to rotate both the front wheels at different velocities for the vehicle to turn (basic principle of a differential).

Locking a differential whether front or rear puts tremendous strain on the drive train (axles, drive shafts, transmission, transfer case) and if the front setup is independent with CV joints, it will be the weak link in the entire chain thereby a possibility of a failure, especially in the hands of a novice.

Typically the rear end of most such types of vehicles is stronger and is the safe bet for an MLD.

In my limited view, MLD on the rear axle should suffice for 99.9% of scenarios unless you're doing technical rock crawling.

Last but not least Mahindra must have realized that 0.01% of its user base is actually encountering a situation where both front and rear MLDs need to be engaged.

I have seen Wranglers equipped with a simple low-range transfer case driven by knowledgeable drivers fly past Rubicons with MLDs on both axles in the hands of amateurs.

[MithunSathianat]

Originally Posted by Vikram Arya

The Front axle of a 4X4 can be equipped with a manual locking differential however there are some added complexities in the case of Thar that make it a challenging scenario...

Thank you for explaining in detail

With solid axle in Jimny, I believe there is more room for suspension modifications than the Thar.
There is air-locker already available from ARB and other manufacturers in the global market for Jimny if one is interested.
With a good lift kit, tyres and air-lockers Jimny would be unstoppable

[Sankar]

IFS and CV joints does not seem to be a limiting factor for the use of front locking differentials going by the number of IFS toyotas equipped with front lockers and selection of front diffs available for these IFS toyotas.

[Earthroamer]

Originally Posted by Sankar

IFS and CV joints does not seem to be a limiting factor for the use of front locking differentials going by the number of IFS toyotas equipped with front lockers and selection of front diffs available for these IFS toyotas.

Yes IFS and cv joints are not much of a limiting factor to employ front locking differential, but cv joints are potential points of failure when it comes to articulation as opposed to a solid axle.

Most of the times, steering the vehicle in the right direction is very much required to get out of the obstacle, which would be completely taken away by locking the front differential. Even when one of the front tyre is slipping, you can get out of it just by using 4Low gearing and steering in the right direction. One of the scenarios where locking on the front differential would be required is, when both the front and rear tyres are slipping, and locking the rear makes the weight of the entire vehicle pivot to the rear tyre with traction, especially while going uphill. This creates a potential for the vehicle to flip over and locking the front would certainly prevent it. Again, this scenario would be very technical and many of the off-roaders would stay away from it, including myself.

[Samurai]

So, I was writing the Wrangler review last weekend and came to the section describing LSD and BLD. I thought maybe I can plonk the LSD video from My Cousin Vinny, and looked it up. Then I noticed something... Mona Lisa Vito was wrong!!!

She describes the Limited Slip Differential incorrectly at 1:15 video position. How did I not notice it all this time? Too caught up in the court room drama I guess. She also says power instead of torque, which is fine for non-technical audience.

https://youtu.be/LFdpIM5k_Sk

Originally Posted by IMDB

Mona Lisa Vito: The car that made these two, equal-length tire marks had positraction. You can't make those marks without positraction, which was not available on the '64 Buick Skylark!
Vinny Gambini: And why not? What is positraction?
Mona Lisa Vito: It's a limited slip differential which distributes power equally to both the right and left tires. The '64 Skylark had a regular differential, which, anyone who's been stuck in the mud in Alabama knows, you step on the gas, one tire spins, the other tire does nothing.

She is describing open differential, instead of limited slip differential. The whole purpose of LSD is to send more torque to the wheel with traction, or unequal torque to the left and right wheels.

[BlackBeard]

Originally Posted by Samurai

Then I noticed something... Mona Lisa Vito was wrong!!!

She describes the Limited Slip Differential incorrectly at 1:15 video position.

She also says power instead of torque, which is fine for non-technical audience.

She is describing open differential, instead of limited slip differential. The whole purpose of LSD is to send more torque to the wheel with traction, or unequal torque to the left and right wheels.

IIRC, she claims that the accused drove off in a vehicle with "positraction" LSD fitted, which was proved by the equal marks made by its rear tires as it drove over the kerb, without a LSD one wheel would have been spinning as in an open differential, NO? The wheel that drove over the kerb was aided by the LSD else it would have been spinning!

By regular differential she meant an open differential and of course torque was replaced by power

[Samurai]

Originally Posted by BlackBeard

IIRC, she claims that the accused drove off in a vehicle with "positraction" LSD fitted, which was proved by the equal marks made by its rear tires as it drove over the kerb, without a LSD one wheel would have been spinning as in an open differential, NO? The wheel that drove over the kerb was aided by the LSD else it would have been spinning!

Yes, but... what has that got to do with my post?

[BlackBeard]

I do not understand where she has described an open differential as a LSD?
especially when she specifies the operation of a regular differential in the very next sentence.

I think the liberal usage of traction, power and torque has created confusion!

[Samurai]

Originally Posted by BlackBeard

I do not understand where she has described an open differential as a LSD?

Let's consider the function of open differential, limited slip differential and locked differential.

Open Differential: Sends equal torque to each wheel while allowing different speeds.
Limited Slip Differential: Sends unequal torque to each wheel while allowing different speeds.
Locked Differential: Sends unequal torque to each wheels while not allowing different speeds.

Now listen to the video at 1:15, she says LSD distributes power equally to left and right tyres. Oops! Not true. She is describing open differential.

[DirtyDan]

Originally Posted by Samurai

She is describing open differential, instead of limited slip differential. The whole purpose of LSD is to send more torque to the wheel with traction, or unequal torque to the left and right wheels.

First, the bump (curb) in this flick is irrelevant in regards to differentials. What Ms. Vito is describing is the equal power to both wheels on a flat surface of uniform traction like the asphalt shown. Both wheels have the same torque in this instance because the traction is the same as evidenced by the equal rubber tracks. Ms. Vito says it a little awkwardly, but she is correct. She is also light years better looking than Samurai and that alone make her correct.

For clarification, the defendant's car could NOT have made these rubber tracks because it did not have LSD (positraction). The defendants car had and open differential which would have layed down one track of rubber, not two. The REAL bad guys, who made the tracks, had to have been driving a different model car that DID have LSD. Case closed, let's get a beer and find out if Ms. Vito has a sister. (The actress is Marisa Tomei who has had a moderately successful career and is regarded as extremely bright.)

[Samurai]

Originally Posted by DirtyDan

What Ms. Vito is describing is the equal power to both wheels on a flat surface of uniform traction like the asphalt shown. Both wheels have the same torque in this instance because the traction is the same as evidenced by the equal rubber tracks.

Sorry Dan, you are not making any sense. Under the circumstances you are describing, there is no difference between the behavior of open and limited slip differential.

Originally Posted by DirtyDan

For clarification, the defendant's car could NOT have made these rubber tracks because it did not have LSD (positraction).

If both wheels had uniform traction, why would LSD even matter?

[DirtyDan]

Originally Posted by Samurai

Sorry Dan, you are not making any sense. Under the circumstances you are describing, there is no difference between the behavior of open and limited slip differential.
If both wheels had uniform traction, why would LSD even matter?

Make sense? Every word I used is in the dictionary and the grammar is correct. If you accelerate hard with an open differential you will likely lay down ONE track of rubber, not two.

[Samurai]

Originally Posted by DirtyDan

If you accelerate hard with an open differential you will likely lay down ONE track of rubber, not two.

Because.... one of the tyre loses traction before the other, right?

Then with LSD, the wheel with traction gets more torque than the spinning wheel. Because LSD can distribute unequal torque to right and left tyres, not what she said. Q.E.D

[BlackBeard]

Originally Posted by Samurai

Open Differential: Sends equal torque to each wheel while allowing different speeds.
Limited Slip Differential: Sends unequal torque to each wheel while allowing different speeds.
Locked Differential: Sends unequal torque to each wheels while not allowing different speeds.

Now listen to the video at 1:15, she says LSD distributes power equally to left and right tyres. Oops! Not true. She is describing open differential.

Originally Posted by DirtyDan

What Ms. Vito is describing is the equal power to both wheels on a flat surface of uniform traction like the asphalt shown. Both wheels have the same torque in this instance because the traction is the same as evidenced by the equal rubber tracks. Ms. Vito says it a little awkwardly, but she is correct.

For clarification, the defendant's car could NOT have made these rubber tracks because it did not have LSD (positraction). The defendants car had and open differential which would have layed down one track of rubber, not two. The REAL bad guys, who made the tracks, had to have been driving a different model car that DID have LSD.

This is what I found in the internet, link given below. What DD & Ms. Vito said is mentioned here. BTW, DD she indeed has aged well, seen the movie Lincoln lawyer?

An LSD’s main job is directing torque where it’s needed. When you’re driving in a normal manner a positraction limited slip differential is pre-loaded and provides equal traction to both wheels. Mashing the throttle, taking a tight corner aggressively, or working through loose gravel trails will result in the limited slip differential limiting wheel spin across the drive axle by permitting the axle shafts to spin at different speeds while continuously trying to balance the application of torque between the two axles. This results in transferring more power to the wheel with the best traction which enhances the grip, control, and the predictability of the vehicle.


https://www.randysworldwide.com/blog...-differentials

[DirtyDan]

Originally Posted by Samurai

Because.... one of the tyre loses traction before the other, right?

Then with LSD, the wheel with traction gets more torque than the spinning wheel. Because LSD can distribute unequal torque to right and left tyres, not what she said. Q.E.D

Yup! Lots of variables...unequal surfaces, unequal weight of vehicle on each tyre etc....are all going to plant one tyre and squeel the other, most likely. This is especially true of very high powered North American cars. You see this happen in North America a lot.

As to whether Ms Vito said it perfectly, if I were still an alpha geek computer programmer I might toddle over to Ms Vito's desk and ask for clarification...in fact, I might go back to her desk for lots and lots of clarification.