Sponsored

Driveline Lock, 4WD on winter roads

Jtphoto

Well-Known Member
First Name
Jeff
Joined
Dec 10, 2017
Threads
15
Messages
1,775
Reaction score
2,065
Location
Thunder Bay ON
Vehicle(s)
2022 Rubicon Xtreme Recon Granite Crystal
So, I never hear anyone discuss or even mention “Driveline Lock up”. How many people even know it’s “a thing”.
Have you ever heard someone say that 4wd helps you take off from a stop faster on slipper roads but doesn’t help you slow down. Well that is not necessarily true. Vehicles have built in brake biasing. Most vehicles are biased to most of the braking done by the front ( Jeeps not so much). What Driveline Lock does is balance the braking equally to front and back.
What is Driveline Lock you ask. What it is, is the simple fact that when in 4wd the front and rear are now tied together by the driveline. If you had no rear brakes at all and only front brakes, when you hit the brakes the rear wheels would still stop you as if they had brakes on because they are directly tied to the front wheels. The rear wheels cannot turn any faster or slower then The front wheels. If you lock up the front brakes the back wheels will lock up just the same.
This “Driveline Lock” is demonstrated well on 4wd ATV that have independent front and rear brakes. There is also a warning sticker on most ATVs (my 2000 Honda Foreman has this warning sticker) indicating DriveLine Lock in 4WD affects braking. In other words if you are going fast in 4wd on loose Gravel and hit the rear brake only, the front will still lock up.
This just an FYI. Driveline Lock can help you slow down faster in 4WD but you have to be aware of it and how it works. It is also the same thing that can get you into trouble if you touch the brakes when you try and corner too fast in 4WD on slippery roads ..
Sponsored

 

AcesandEights

Well-Known Member
First Name
Aces
Joined
Aug 19, 2021
Threads
29
Messages
3,217
Reaction score
6,230
Location
So. Oregon
Vehicle(s)
2022 Jeep Rubicon 2D, with extra guacamole
Occupation
I'm often occupied, by many things, often at the same time
So what? Just a random fact?
 

GSLSE21B

Well-Known Member
First Name
Dan
Joined
Nov 10, 2020
Threads
6
Messages
417
Reaction score
693
Location
Fair oaks
Vehicle(s)
2021 jLURD
You would have to have front and rear lockers engaged for 4 wheels to be “locked” in rotation
 

Pinion

Well-Known Member
First Name
Rob
Joined
Mar 17, 2021
Threads
9
Messages
2,587
Reaction score
19,560
Location
Hull, MA
Vehicle(s)
1971 FJ40, 22 Rubicon Unlimited
Occupation
Project Manager
Are you just talking about engine braking?
 

AcesandEights

Well-Known Member
First Name
Aces
Joined
Aug 19, 2021
Threads
29
Messages
3,217
Reaction score
6,230
Location
So. Oregon
Vehicle(s)
2022 Jeep Rubicon 2D, with extra guacamole
Occupation
I'm often occupied, by many things, often at the same time
Are you driving a manual or an automatic, and are you utilizing the clutch?
 

Sponsored

OP
OP
Jtphoto

Jtphoto

Well-Known Member
First Name
Jeff
Joined
Dec 10, 2017
Threads
15
Messages
1,775
Reaction score
2,065
Location
Thunder Bay ON
Vehicle(s)
2022 Rubicon Xtreme Recon Granite Crystal
You would have to have front and rear lockers engaged for 4 wheels to be “locked” in rotation
Not at all. The driveline is still locked. Even with an open diff At least one of the rear wheels and likely both will lock up with the front as you still have drive shaft input. ATVs have an open front diffs.
 
OP
OP
Jtphoto

Jtphoto

Well-Known Member
First Name
Jeff
Joined
Dec 10, 2017
Threads
15
Messages
1,775
Reaction score
2,065
Location
Thunder Bay ON
Vehicle(s)
2022 Rubicon Xtreme Recon Granite Crystal
OP
OP
Jtphoto

Jtphoto

Well-Known Member
First Name
Jeff
Joined
Dec 10, 2017
Threads
15
Messages
1,775
Reaction score
2,065
Location
Thunder Bay ON
Vehicle(s)
2022 Rubicon Xtreme Recon Granite Crystal
Are you just talking about engine braking?
No Driveline lock is just the front wheels mechanically connect to the rear. Put a vehicle on a hoist in 4WD, turn a rear wheel have someone hold the other rear wheel from turning backwards and one or both of the front wheels will turn.
 
OP
OP
Jtphoto

Jtphoto

Well-Known Member
First Name
Jeff
Joined
Dec 10, 2017
Threads
15
Messages
1,775
Reaction score
2,065
Location
Thunder Bay ON
Vehicle(s)
2022 Rubicon Xtreme Recon Granite Crystal
Are you driving a manual or an automatic, and are you utilizing the clutch?
Auto or Standard, Clutch doesn’t matter they are tied together through the transfer case.
 

Pinion

Well-Known Member
First Name
Rob
Joined
Mar 17, 2021
Threads
9
Messages
2,587
Reaction score
19,560
Location
Hull, MA
Vehicle(s)
1971 FJ40, 22 Rubicon Unlimited
Occupation
Project Manager
I understand the concept. I've been under rigs off and on for 25 years.
 

58Willys

Well-Known Member
First Name
Geoff
Joined
Jan 2, 2022
Threads
5
Messages
582
Reaction score
797
Location
Western Washington
Vehicle(s)
2018 JL Sport
A rolling tire has more traction/directional stability than one that is locked up and skidding. In 2WD and ABS you will have far more control than if your “drivelines are locked” and thus your wheels being all locked together. In 2WD one wheel may lock up, but the other could be turning and keeping going.
Sponsored

 
 



Top