ABLS or LSD

Bluto · 04-12-2004, 07:37 AM

Should Nissan have equipped the Titan with a Limited Slip Differential, or is ABLS good enough/better?

The rear locker is a nice option. But it only can be engaged in 4Lo. 2wd and 4hi will be used most often, along with the rear differential. ABLS applies braking force to a wheel losing traction, directing power to the other wheel. It works on the front and rear axle, which have open differentials. Are the front and rear ‘limited-slip capabilities’ as good as having a rear LSD?

Which transfers more torque, LSD or ABLS?
A clutch type Limited Slip is limited to how much torque the spring pack and clutches will hold.

In ABLS a device compresses brake fluid. ABLS is limited to how much brake force the pump can apply. Has Nissan published how much torque ABLS can transfer to the side with more traction?

Which works faster?
A Limited Slip is mechanical. It transfers power using clutches when traction loss is sensed.

ABLS detects traction loss electronically. Then a pump compresses brake fluid to apply a brake. How fast can the pump work?

What if your brake fluid is hot? The brakes are fading from heat, in the water, snow, mud? Relying on the brake system to stop the truck and provide traction seems a bit much. None of this is a problem with an LSD.

Quad T · 04-12-2004, 10:22 AM

Quote:

Originally Posted by Bluto

The rear locker is a nice option. But it only can be engaged in 4Lo. 2wd and 4hi will be used most often, along with the rear differential. ABLS applies braking force to a wheel losing traction, directing power to the other wheel. It works on the front and rear axle, which have open differentials.

Wow, only 6 votes so far, and after all the heat in the April 4 locker thread...

Bluto, let there be no confusion, I voted for the LSD. I will not go into detail because I feel I have already beaten a dead horse in the other thread. I will however say, I believe Nissan has missed the mark with the ABLS. In addition, the least they could have done was made it optional as an individual item. Unfortunately everything I want is tied into some big option package that contains more things I don't want.

Not having an LSD is a big issue to me, and there is no way someone can convince me that trying to get through thick mud it would be better to have the computer applying brakes as the driver was applying gas instead of a LSD hooking up both back tires and the driver controlling the amount of spin with the gas pedal. Sometimes the only way through a situation is to get a little spinning action going, if you are running too slow the mud will just suck you in.

keane · 04-12-2004, 11:08 AM

Quote:

Originally Posted by Quad T

Wow, only 6 votes so far, and after all the heat in the April 4 locker thread...

Bluto, let there be no confusion, I voted for the LSD. I will not go into detail because I feel I have already beaten a dead horse in the other thread. I will however say, I believe Nissan has missed the mark with the ABLS. In addition, the least they could have done was made it optional as an individual item. Unfortunately everything I want is tied into some big option package that contains more things I don't want.

Not having an LSD is a big issue to me, and there is no way someone can convince me that trying to get through thick mud it would be better to have the computer applying brakes as the driver was applying gas instead of a LSD hooking up both back tires and the driver controlling the amount of spin with the gas pedal. Sometimes the only way through a situation is to get a little spinning action going, if you are running too slow the mud will just suck you in.

Not what he said!!!

The LSD is only working on the back, the ABSL system works on the front as well (I Think!!!) which is much better. After reading Austin's explanation and not wanting to beat the thread to death - I cancelled out Quad-T. Sorry big guy!

bestatchess · 04-12-2004, 11:23 AM

In a situation where one wheel is spinning, I believe that in both ABLS and LSD, the effective transmitted torque will be limited by the traction of the other wheel, and not by the characteristics of the ABLS or LSD.

I would like to have ABLS plus push button front and rear locking differentials (ala Jeep Rubicon).

Quad T · 04-12-2004, 11:37 AM

Quote:

Originally Posted by keane

After reading Austin's explanation and not wanting to beat the thread to death - I cancelled out Quad-T. Sorry big guy!

No problem. Just make sure you pack your waiders, because you will need them to walk back to get a winch in the mud...

Austin · 04-12-2004, 12:12 PM

Quote:

Originally Posted by bestatchess

I would like to have ABLS plus push button front and rear locking differentials (ala Jeep Rubicon).

Ditto.

Oh, and I voted for ABLS.

JS02 · 04-12-2004, 12:22 PM

I think it should have both for an option. They each could have advantages in given circumstances. I would think they could make the elocker work with the ABLS even in 4WDHI.

tnbowhunter · 04-12-2004, 12:29 PM

i voted for abls, but in reality i think both systems have their merits, and i would prefer to have them both, but seeing as that is not an option (so far) i would rather have the abls.
for everyday driving in snow or possibly sand i think that abls is the better system as it works automatically.
if i was stuck in a ditch or in deep mud or if i purchased this truck to take off road a lot a locker would be the better system.
since i didn't buy this truck to take off road much, mainly as a work truck around the farm, pulling logs etc., and for pulling my camping trailer i think abls is the way to go.
it all boils down to the intended use in which you purchased your truck

PEACE OUT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

kmfernandez · 04-12-2004, 01:57 PM

Quote:

Originally Posted by Quad T

No problem. Just make sure you pack your waiders, because you will need them to walk back to get a winch in the mud...

So if you're at a dead stop and have trouble getting traction, the brakes kick in...? Considering the confusion around these systems the vote sort of make sense, but I wouldn't have abls either. I have no 4wd because I really dont need it, but I intend to get a good aftermarket solution. I wrote to EATON and RichmodGear (PowerTrax), and I haven't heard back from Eaton yet, but Stu Hamilton at Richmond Gear wrote back: "Currently we do not offer anything for this vehicle(Titan). We have advised our marketing dept. of your request." If anybody has a good suggestion for a locker or limited slip or some other (aftermarket) traction control system one can turn on when you need it, let us know

bestatchess · 04-12-2004, 02:03 PM

Quote:

Originally Posted by kmfernandez

or something you can turn on when you need it, let us know

That would either be a wench or a winch, depending on the situation.

kmfernandez · 04-12-2004, 02:10 PM

Quote:

Originally Posted by bestatchess

That would either be a wench or a winch, depending on the situation.

...he just couldn't resist could he... ; try this Mr betsatchess: If anybody has a good suggestion for a locker or limited slip or some other (aftermarket) traction control system one can turn on when you need it, let us know

bestatchess · 04-12-2004, 02:22 PM

Quote:

Originally Posted by kmfernandez

...he just couldn't resist could he... ; try this Mr betsatchess: If anybody has a good suggestion for a locker or limited slip or some other (aftermarket) traction control system one can turn on when you need it, let us know

O.K., a wench that knows how to put tire chains on, and then perhaps a bit of mud wrestling aftewards.

Bluto · 04-12-2004, 02:41 PM

Quote:

Originally Posted by Quad T

Wow, only 6 votes so far, and after all the heat in the April 4 locker thread...

I felt the topic deserved it's own thread.

The ABLS seems like a pruned version of VDC. Both use the brake system and sensors. ABLS is not dynamic, nor does it affect engine output.

I don't see how the brake system can modulate fast enough to perform like a LSD. If the system is not fluid/fast enough it could make controlling the truck difficult.

I don't like the thought of having the brakes work against the engine. Brakes aren't designed to clamp and transfer torque, especially 380 ft-lbs. The brakes will lose. They are for stopping vehicles.

I'm concerned about warped rotors, glazed pads, reduced brake life, and failed system components. Operating on the front and rear is nice. But can it match the performance of a LSD? I wish Nissan would provide more technical merits of the system.

Austin · 04-12-2004, 03:18 PM

Quote:

Originally Posted by Bluto

I don't like the thought of having the brakes work against the engine.

The brakes aren't working against the engine. They're working *with* the differential.

Quote:

Originally Posted by Bluto

Brakes aren't designed to clamp and transfer torque, especially 380 ft-lbs. The brakes will lose. They are for stopping vehicles.

The brakes will definitely not lose. They are specifically designed to clamp, which, due to their mounting location, means they're specifically designed to stop rotation of the tire/wheel. Without ABS, you'd be able to lock up the wheels anytime you wanted to. Brakes that size have the clamping force necessary.

You're correct in saying that the braking system is not designed to transfer torque... but that's not what's happening. The braking system (as it's used by ABLS) simply gives the wheel some resistance to turning - allowing torque to be generated - and that allows the open differential to deliver torque to the other side.

Take an extreme case - right rear wheel up in the air spinning free, left rear wheel on the ground. RR wheel has zero traction (there is nothing for it to push against), therefore, due to the open differential, zero torque is generated in the rear.

Thanks to the open differential and one wheel having zero traction, the truck is stuck.

Enter ABLS.

ABLS clamps the RR brake caliper shut (it'll never actually go this far - I'm just giving an extreme example). The RR wheel now has effectively infinite traction - allowing infinite torque to be generated and distributed equally to both sides. This allows the torque necessary to move the truck to be delivered to the LR wheel. Truck not stuck.

bestatchess · 04-12-2004, 03:55 PM

Quote:

Originally Posted by Bluto

I felt the topic deserved it's own thread.

I don't like the thought of having the brakes work against the engine. Brakes aren't designed to clamp and transfer torque, especially 380 ft-lbs. The brakes will lose. They are for stopping vehicles.

380 Ft-lbs is peanuts for a braking torque for a vehicle with power brakes and big rotors (like the Titan).