Do 4th gen 1500 4x4s have "active LSD" - or not?

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62Blazer

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Doesn't seem like a very good system if the driver has to "understand it" for it to work.

So if all these trucks have this why are they able to spin a wheel when in snow/ice? Like I said, I'm pretty sure this system DOES work on my truck. Haven't had it in snow but in mud the spinning wheel only spun one or two revs before the other wheel started pulling.
In regards to why a truck may still spin only one tire, such as when on ice. There is simply a limit to how much torque can be transferred from the low traction tire (spinning tire) to the one with traction. Part of that limit is in the programming of the system, so basically how much brake force the system applies to the spinning tire. Keep in mind that there is a balance of how much braking to apply to the spinning wheel before you get to the point of diminishing returns....if you apply too much braking you basically lock the tire up in order to get the other tire spinning, but you are now stuck because the one tire is locked up........ There is also the issues of strength of the components since applying to much brake load can put a lot of stress on parts.

One thing to clarify (I'm not specifically replying to this post, but just overall comments that I see)....is that just because one tire is spinning and other tire is not does not mean the system is not working. This goes for BLD/electronic traction control or a limited slip differential. Either system is still transferring torque to the wheel with traction, but it just can't transfer enough torque for it to spin or make the vehicle move forward. For example if you have one tire in the air it basically takes almost zero torque to spin. Even you transfer 100% of the torque to the other tire that is 100% x 0 which equals 0.
 

Mister Luck

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If you have a V8 1500 with the 8 speed transmission you probably have an active LSD, the 2500 that use a 6 speed transmission or any other truck (in stock configuration) that uses a 6 speed transmission probably does not.
Diesel’s have a higher torque / horsepower curve and therefore have a different axle ratio pairing.

The full time 4x4 off-road enthusiasts tend not to use anti-roll bars on the rear or front axle . An anti-roll bar’s intention is to keep both wheels of the same axle on the pavement which helps LSD’s perform as intended but are not much help off pavement.

I use 4low in my 1500 with a v8 and it works for most situations where extra traction is needed but I’m not rock crawling either.
 

2020PW

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You don’t need lockers, you can lock up both axles without LSD or BLSD
 

62Blazer

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Another comment is that electronic traction control that uses the brakes to transfer power has been very common since the early 2000's and some form of it is found on the majority of vehicles made today. My wife's last minivan was a 2007 model and had standard brake based traction control on it. If you were spinning on a patch of snow you could feel and hear the brake kick in on the spinning wheel. Not 100% sure but traction control has likely been a standard part of a Ram truck for years.
 

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Check this post to disable ESC.

 

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I have tried this a few times and it doesn't do anything no matter how long I hold it down. 2015 1500.

This does work as described on my '21 Classic Warlock. After holding the ESC button for about 6 seconds, with the 4x4 Lock engaged, you hear a ding and the message below pops up.

This truck has the LSD option, I'm not sure if that makes any difference.

ESC off.jpg
 
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ram1500rsm

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A lot of people up their trucks in 4low when stuck in snow..."Better throttle and wheel speed control". However, it you read closely this also disengages just about everything including the BLDS........
It doesn't. BLD works in 4hi or 4lo. 4lo disables the traction control crap that will cut power to the wheels when the whees start spinning. is supposed to partially of when you disable the tc off via the switch and fully disabled when you go to 4low, but that doesn't disable the BLD system.
 

ram1500rsm

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If you have a V8 1500 with the 8 speed transmission you probably have an active LSD, the 2500 that use a 6 speed transmission or any other truck (in stock configuration) that uses a 6 speed transmission probably does not.
Diesel’s have a higher torque / horsepower curve and therefore have a different axle ratio pairing.

The full time 4x4 off-road enthusiasts tend not to use anti-roll bars on the rear or front axle . An anti-roll bar’s intention is to keep both wheels of the same axle on the pavement which helps LSD’s perform as intended but are not much help off pavement.

I use 4low in my 1500 with a v8 and it works for most situations where extra traction is needed but I’m not rock crawling either.
If the truck is equipped with the feature it should work regardless of trans or motor. I'm almost positive It should be standard in all 4th gen RAM's 1500's and up, so 2009 and up. I'm not able to verify my comment because i never had one that old, but it's the same system Jeep Wranglers have been using for years in the JK models, so 2007 and up.
I have a 14 Hemi with the 6 speed trans, and BLD works great considering i don't have a rear locker, only the OE rear LSD

with 35's

or with 37's
 

Mister Luck

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I agree if the truck is equipped from the dealer it should work regardless,

but just a quick search will give many different options available for differentials with similar names, my experience is from browsing through diff covers and the option for the newer 12 bolt might look like the same diff but it is not.


AAM 9.25 12 bolt is not the 9.25 12 bolt found on front differentials of the 2500/ 3500

In addition I’ll provide a link to various types of LSD ‘s

I believe anything made after 09 would be considered to be electronic braking.

Jeep

General LSD documentary
 
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ram1500rsm

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BLD is or should be standard in all 4th/5th gen gen 1500 trucks, I say should because i don't recall RAM marketing advertising the feature. it's independant from the rear diff and it's not a dealer option nor it's something you pay as an optional add-on or anything like that. it's a logic built into the truck engine management system and uses the brakes to control wheel action.
This is an old article but it explains how the system works

I think back in 2009 they started offering both transfer cases 44-44 and 44-45, the 44-44 is the best of the 2 as it clutches don't slip like the 45 so more aggressive wheeling you want the 44-44.

There was a physical LSD device which some us of have, don't know when it was offered initially. You can check if you have with your vin# here https://fcacommunity.force.com/RAM/s/equipment-listing
 

metalchewy

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In 2009, 1500s only came with NV243 and NV246 transfer cases.

In 2010, 1500s only had MP3010, NV243 and NV246 available as transfer cases.
 

ram1500rsm

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In 2009, 1500s only came with NV243 and NV246 transfer cases.

In 2010, 1500s only had MP3010, NV243 and NV246 available as transfer cases.
So the NV243 will have a similar operation as the 44-44. Not sure how good was the 246 in terms of slipping like the 44-45 seems to do. Seems the 45 was the chitty one :). I Had the select trac 242 in my 01 Jeep GC, and that one didn't slip, the Jeep was fully open though, no electronics, no LSD. That's how you learn the ropes with something you have to fight when the axels go with one wheel in the air.

This is a 2010 RAM 1500, easy to see how BLD did it's thing back then

If we look at a fully open diff SUV vs a RAM with the BLD electronics is not even funny to drive fully open without any real LDS oe electronics unless you know what you're doing and still...Not sure what year this RAM is though, it has 2013 and up grill but between BLD and LSD is makes the job super easy

 
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TFL Truck just made a video showing the brake locking in action. Shows the importance of giving it steady throttle as it takes a moment for the computer to really clamp down on the slipping wheels.
This is exactly how I understood it should work - and exactly how it does work in my truck.

According to my owner's manual, even if you turn traction control off BLDS is still active. So what are all these "YouTube nay-sayers" doing that show it DOESN'T work? How are they getting stuck with some wheels spinning and the others doing nothing - like BLDS isn't working at all?
 

kurek

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The BLD in my 2015 has never failed to operate exactly as advertised. Combined with the factory anti-spin diff, even if somebody offered to put a selectable locking rear diff in my truck for free and buy me a sandwich I'd probably thank them and say no because I have never been in a situation in this truck where a locker would have changed the outcome. To be clear I have owned a 4x4 with selectable lockers and am aware of how they perform. The BLD feature tensions the anti-spin diff enough that it may as well be a lock on loose, wet or mogul surfaces.

I do not take this truck through rock gardens like a moon buggy so the control advantage in that terrain is a moot point.

My pretend Jeep has BLD as well and while it does work the same way, it does not include a limited slip to supplement it and that means all applications of brake to the spinning wheel necessarily cut the final drive gear ratio in half. Since the pretend Jeep has no low range transfer case and a 4 cylinder engine + light duty automatic trans it becomes very easy to stall the transmission when BLD is called into action while climbing up hill.

 
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