Locking the Diff...

[Thai]

I thought that was the cool thing about T-3. I understood that even with no resistance on one end the other would still get power. What am I missing? I know earlier versions required some resistance on the slipping side/end. http://www.torsen.com/files/Torsen T-3 Technical Sheet.pdf

Of course this means I am going to have to put the floor jack under my back axle and drive up my driveway, or at least try And yes I know, to be fair I must unplug at the master cylinder to defeat ATRAC and VSC. That brings up the point that the ATRAC would force some power forward or backwards based on the ATRAC slowing the wheels on the spinning axle, right?

:cheers:

Chris, i read nothing in that PDF file to tell me that it is any different than previous Torsen units. The "cool" thing about the T3 unit is the variable torque split under varying surfaces (65/35, 70/30, etc.)...and that it is a compact unit.

Don't ask me to find it, but there was a story of a guy on Clublexus (or was it here?) where he submerged his front axle (on a GX470 i think) in mud and was completely stuck...until he locked his center diff.

I think that ATRAC compares speed differences between two wheels on the SAME axle...VSC (stability control) is the system that monitors all wheel speed at the same time. Thus, with ATRAC, if the whole axle loses traction, then ATRAC will find nothing wrong (since both wheels on the SAME axle are spinning at the same rate) and thus won't intervene.

So, it is quite advantageous to lock the center diff while off-roading because:
1. turn off VSC
2. keep the center diff from guessing how much power goes to each axle...50/50 fixed is what you want
3. get you out of the rare situation where either front or rear axles have completely loss traction

For more technical reasons, see: http://www.toyota-4runner.org/showthread.php?threadid=12

 

[CJ3Flyr]

Chris, i read nothing in that PDF file to tell me that it is any different than previous Torsen units. The "cool" thing about the T3 unit is the variable torque split under varying surfaces (65/35, 70/30, etc.)...and that it is a compact unit.

Don't ask me to find it, but there was a story of a guy on Clublexus (or was it here?) where he submerged his front axle (on a GX470 i think) in mud and was completely stuck...until he locked his center diff.

I think that ATRAC compares speed differences between two wheels on the SAME axle...VSC (stability control) is the system that monitors all wheel speed at the same time. Thus, with ATRAC, if the whole axle loses traction, then ATRAC will find nothing wrong (since both wheels on the SAME axle are spinning at the same rate) and thus won't intervene.

So, it is quite advantageous to lock the center diff while off-roading because:
1. turn off VSC
2. keep the center diff from guessing how much power goes to each axle...50/50 fixed is what you want
3. get you out of the rare situation where either front or rear axles have completely loss traction

For more technical reasons, see: http://www.toyota-4runner.org/showthread.php?threadid=12

Ok. I've read and reread the great post you have at that link. One of the confusing (to me) statements is this: "TORSEN T-3 Traction Differentials are available with a locking capability range of 20-30% and a nominal split from 65:35 and 35:65" That's where I'm getting confused/mislead. If one end on the ice equaled 100%/0% torque division then the above statement would be false

The stuck GX probably climbed out for two reasons: The 50/50 torque split and lack of VSC/TRAC cutting the power. My point/confusion centers around my belief that there would be some power available if the front wheels were on ice and the rears weren't. If there wasn't some power available then why have the T-3, why not just and old style open diff with a lock like a NP203?

I have no doubt what you said is true about the benefits of locked center diff for super slippery conditions, you're right I am just trying to get my head wrapped around the T-3.

:cheers:

 

[Thai]

One of the confusing (to me) statements is this: "TORSEN T-3 Traction Differentials are available with a locking capability range of 20-30% and a nominal split from 65:35 and 35:65" That's where I'm getting confused/mislead. If one end on the ice equaled 100%/0% torque division then the above statement would be false

If there wasn't some power available then why have the T-3, why not just and old style open diff with a lock like a NP203?

:cheers:

I don't know what that statement means. The new T3 diff main benefit is that it is more "on-road" friendly. Thus, around corners, the new 30/70 split provides more natural performance (aka more similar to rear wheel drive sports car). So, it is a more advanced system for your average customer. Remember, most AWD system are like this (rear drive preference). Thus, this T3 system achieves this on a vehicle with a mechanical center diff...to be similar to other on-road AWD system performance.

My opinion.

 

[CJ3Flyr]

I don't know what that statement means. The new T3 diff main benefit is that it is more "on-road" friendly. Thus, around corners, the new 30/70 split provides more natural performance (aka more similar to rear wheel drive sports car). So, it is a more advanced system for your average customer. Remember, most AWD system are like this (rear drive preference). Thus, this T3 system achieves this on a vehicle with a mechanical center diff...to be similar to other on-road AWD system performance.

My opinion.

Makes good sense... As I reflect back on the late 70's- early 80's trucks/Jeeps with full-time 4wd not one of them was known for it's fine road manners:lmao: Suby WRX's they were not. The T4R does have some damn fine on road performance, no question.


:cheers: