Newb 4x4 Question: Front Diff?

[c3k]

I understand the various options available to equip the rear differential; open, limited slip, e-locker.

What about the front differential in 4x4 configurations? If I opt for an e-locker rear, is the front also an e-locker? Or, is the front always a LSD? Or, is it open and relies on traction control (braking the faster wheel) to keep both front tires moving? (Oddly, I cannot find anything on the front wheel drive system.)

I'm also stumped trying to figure out what Ram uses in the transfer case to go from 2-wheel drive to 4-wheel.

Thanks for the info.

 

[SpeedyV]

I understand the various options available to equip the rear differential; open, limited slip, e-locker.

What about the front differential in 4x4 configurations? If I opt for an e-locker rear, is the front also an e-locker? Or, is the front always a LSD? Or, is it open and relies on traction control (braking the faster wheel) to keep both front tires moving? (Oddly, I cannot find anything on the front wheel drive system.)

I'm also stumped trying to figure out what Ram uses in the transfer case to go from 2-wheel drive to 4-wheel.

Thanks for the info.

The front is open (on the 1500).

 

[c3k]

Well, looking here: https://www.moparpartsgiant.com/par...d_drive_line/differential_assembly_front.html

I found that it shows an electronic axle locker. I've attached an image.

I don't know if that e-locker is always present or if it is only there if the rear e-locker is present.

 

[Scram1500]

That actuator is for activation of 4 wheel drive, not an e locker for the front diff. All 4x4s have that actuator, sometimes their wording is confusing

 

[c3k]

That actuator is for activation of 4 wheel drive, not an e locker for the front diff. All 4x4s have that actuator, sometimes their wording is confusing

Thanks. Recognizing my newbness...

That activator is on the passenger side axle coming out of the front differential. I would think the transfer case would have actuator on it (the transfer case) for the output to be directed to the front differential.

And, I understand that some are chain drive? But that doesn't answer how the output from the transmission that feeds INTO the transfer case gets routed to the OUTPUT to the Front Differential. Electronic controlled viscous clutch pack? I know it's not an air locker. Older ones were mechanical. Again, trying to understand what mechanical device is used for the transfer case output to the front.

My guess is that there is an e-locker in the transfer case, since the controls in the Ram cab are electric switches. But, it's just a guess.

Looking at the part diagram I posted, I cannot see how that particular actuator (part 1) affects transfer case output.

*****************

Or, does the transfer case always output power to the front differential input (where the pinion gear shaft comes through item 5 in the diagram), and that actuator labeled "1" somehow pushes the axles to engage with the ring gear???

(The transfer case, BW 48-11, has some sort of can-shaped actuator between the input and output gears. That would, to me, be the actuator for outputting power from the transfer case to the front differential.)



Again, being a newb and shopping for a truck, I want to understand the marketing fluff. I'm sure a lot of you folks have forgotten more about four-wheel drive systems than I'll ever know.

Thanks.

 

[Scram1500]

I should have been more clear, that actuator is for locking the hubs, in the old days you used to have to get out and turn the lock on the front wheels manually. There's another actuator inside the transfer case that engages the output shaft. I really miss the manual lever myself. At any rate the ORP, Rebel and Tradesman have chain drives, all other trims have a clutch as they have 4 wheel auto

 

[SpeedyV]

I should have been more clear, that actuator is for locking the hubs, in the old days you used to have to get out and turn the lock on the front wheels manually. There's another actuator inside the transfer case that engages the output shaft. I really miss the manual lever myself. At any rate the ORP, Rebel and Tradesman have chain drives, all other trims have a clutch as they have 4 wheel auto

The Off-Road Group doesn’t eliminate Auto 4WD.

 

[c3k]

Okay, I've been watching slick marketing videos from Borg Warner. It's still hard to tell what the differences are between the 48-11 and the 48-12. I -think- it is just programming? It seems like they both have a chain drive going to the front output. And the power to that chain drive is determined by a clutch stack. The pressure on the clutch stack is driven by an oil pump (separate from the way the chain spreads the oil around).

But, if the only difference is programming, they would not make separate transfer cases (different part numbers).

I'm still confused.

And, if the front differential is an open diff, well, that's a bit disappointing. Even a limited slip would be better (for as long as the friction additive/clutches last). I guess that's why the Power Wagon's front locker gives it so much better off-road capability. I'm trying to wrap my head around how an open diff can be considered a 4x4 system. I'd think true marketing would call it "3 or 4 by 4, depending on traction".

Ken

 

[devildodge]

4x4 is always a standard 1 front and 1 rear.

Then...you got the first option. Anti spin rear. You get a 1 front and 2 rear...but only once it is activated.

Then you have the next option eLocker. It again is 1 front and 2 rear. This is engaged with a button. No waiting for the clutch packs (or which ever style you have) to grab.

The front actuator is a C.A.D. central axle disconnect. And as stated...takes the place of manual locking hubs. It engages electrically on the new trucks, when the transfer case is engaged.

In 4wd auto mode you can actually end up only sending power to 1 tire. Yes...because of the clutches.

RAM has a real awesome feature though...BLDS

brake lock differential system

Jeep Brake Traction Control Explained | Stellantis Blog

blog.fcanorthamerica.com

This is from jeep...but it is the same system.

We have lots of threads that explain all this here.

Also some threads that show the short comings of making trucks into station wagons and constantly having to have fail safes for the general public you can not be asked to take the time to familiarize themselves with their trucks.

 

[c3k]

4x4 is always a standard 1 front and 1 rear.

Then...you got the first option. Anti spin rear. You get a 1 front and 2 rear...but only once it is activated.

Then you have the next option eLocker. It again is 1 front and 2 rear. This is engaged with a button. No waiting for the clutch packs (or which ever style you have) to grab.

The front actuator is a C.A.D. central axle disconnect. And as stated...takes the place of manual locking hubs. It engages electrically on the new trucks, when the transfer case is engaged.

In 4wd auto mode you can actually end up only sending power to 1 tire. Yes...because of the clutches.

RAM has a real awesome feature though...BLDS

brake lock differential system

Jeep Brake Traction Control Explained | Stellantis Blog

blog.fcanorthamerica.com

This is from jeep...but it is the same system.

We have lots of threads that explain all this here.

Also some threads that show the short comings of making trucks into station wagons and constantly having to have fail safes for the general public you can not be asked to take the time to familiarize themselves with their trucks.

That is a very clear explanation. (The link is great.)

Thanks.

 

[devildodge]

@c3k I have used the BLDS numerous times.

I have a 2500 with the rear anti spin.

What I have found is on Rocky or muddy terrain BLDS works great. The best way to get it to perform is to apply light throttle and just stay in it. This allows the tires to slip and then the BLDS does its thing. What I found is, with snow...you usually end up making ice before BLDS starts to work...and then you are just stuck. Snow needs momentum more than anything.

Another thing with no front locker or limited slip. Turning the wheels back and forth also help with getting traction to each wheel.

As bad as these things grab and grown on hard surfaces in 4wd...a limited slip and especially a locker to the general public is warranty work that may not be covered...if you get what I mean.

 

[eTorqueCoasting]

The Off-Road Group doesn’t eliminate Auto 4WD.

So does ORG change the transfer case or do will get the transfer case that come with the other 4x4 1500s?

 

[jdefoe0424]

So does ORG change the transfer case or do will get the transfer case that come with the other 4x4 1500s?

I believe the only model across the 1500s that gets a different transfer case is a rebel. It's a traditional style and does not feature the auto capability.
It's obvious if you look at the 4x4 switch pod.

Sent from my Moto Z (2) using Tapatalk

 

[eTorqueCoasting]

I believe the only model across the 1500s that gets a different transfer case is a rebel. It's a traditional style and does not feature the auto capability.
It's obvious if you look at the 4x4 switch pod.

Sent from my Moto Z (2) using Tapatalk

Dont have it yet, only ordered and still finding out lots of stuff

 

[devildodge]

ORG does not change the transfer case.

Tradesman and Rebel get the part time

Bighorn Laramie Limited get the auto.

There is talk the Rebel can get the auto as an option now.