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Old 02-19-2019, 03:55 PM   #1
Crazyced
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Question DCCD clutch pack test?

I was playing around with the DCCD pro for my v8 6MT the other day and noticed that idling around at full steering lock and diff at 100% would only result in a slight drag.

Now it was a snow covered surface but when I tried the same experiment in the same spot with my Dodge Durango with the center diff locked it would bring it to a stop (auto trans).

How strong is the binding when you do the same?

A couple of months ago I was able to move the car around with a broken front axle by locking the diff so it can't be that weak but I'm wondering how to test the health of the clutch pack.
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Old 02-19-2019, 04:27 PM   #2
point78
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If I lock my center diff & slowly turn like you are saying, it's a BIG drag.

If I unlock it while it's bound up, it feels like the car just broke in half...
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Old 02-19-2019, 06:15 PM   #3
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You need to ensure the DCCD is electromagnetically locked on a pre-2006 DCCD. DCCDPro may incorporate low speed unlocking to prevent parking lot stick-slip phenomena.

Post-2006, the mechanical diff. was always active until 2015 so you'll feel it more.
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Old 02-20-2019, 10:35 AM   #4
Crazyced
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Quote:
Originally Posted by mrsaturn7085 View Post
You need to ensure the DCCD is electromagnetically locked on a pre-2006 DCCD. DCCDPro may incorporate low speed unlocking to prevent parking lot stick-slip phenomena.

Post-2006, the mechanical diff. was always active until 2015 so you'll feel it more.
DCCDPro has no way to know how fast the car is going. Only has throttle, brake and handbrake sensors (plus g sensor). I also assume manual mode would actually be manual.

Speaking of which, do you know how fast a pre-2006 DCCD is to go from open to lock? I felt a good amount of delay between me twisting the knob to lock and feeling binding when doing the experiment. I'd be curious to know how fast it's supposed to react.
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Old 02-20-2019, 12:58 PM   #5
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Quote:
Originally Posted by Crazyced View Post
DCCDPro has no way to know how fast the car is going. Only has throttle, brake and handbrake sensors (plus g sensor). I also assume manual mode would actually be manual.

Speaking of which, do you know how fast a pre-2006 DCCD is to go from open to lock? I felt a good amount of delay between me twisting the knob to lock and feeling binding when doing the experiment. I'd be curious to know how fast it's supposed to react.
Well, it's an electrical signal, so somewhere around the speed of light, minus resistance of wires and processing time of the DCCDPro. In other words, there shouldn't be a delay.

DCCDPro uses algorithms not documented as well as MapDCCD - I suggest you contact the manufacturer and bounce your question off them.
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Old 02-20-2019, 02:40 PM   #6
Crazyced
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Quote:
Originally Posted by mrsaturn7085 View Post
Well, it's an electrical signal, so somewhere around the speed of light, minus resistance of wires and processing time of the DCCDPro. In other words, there shouldn't be a delay.
hahaha I'm sure there's no delay for the coil to be energized. But how long for the pilot clutch to start moving enough to push the balls into the intermediate clutch plate to the point of actually locking the diff, that's the question. I assume there's a reason they added a mechanical clutch in '06.

Good point, I'll ask DCCDPro.

Last edited by Crazyced; 02-20-2019 at 02:49 PM.
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Old 02-21-2019, 10:32 AM   #7
point78
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Quote:
Originally Posted by Crazyced View Post
DCCDPro has no way to know how fast the car is going. Only has throttle, brake and handbrake sensors (plus g sensor). I also assume manual mode would actually be manual.

Speaking of which, do you know how fast a pre-2006 DCCD is to go from open to lock? I felt a good amount of delay between me twisting the knob to lock and feeling binding when doing the experiment. I'd be curious to know how fast it's supposed to react.
Mine is a 2004 6mt.

It's been a while since I used the DCCDpro, I switched over to Mapdccd.

I do remember I would pull one notch of ebrake when doing like a full steering turn around in a parking lot. (To unlock the center diff). There always seemed to be a little lock going on, unless it turned the knob all the way down.

It's instant-there's no perceived delay.

If it was already bound up I'd get a Big "Bang" noise & you could really feel it through the whole driveline (when I pulled the ebrake )
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Old 02-21-2019, 02:56 PM   #8
Crazyced
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Quote:
Originally Posted by point78 View Post
Mine is a 2004 6mt.

It's been a while since I used the DCCDpro, I switched over to Mapdccd.

I do remember I would pull one notch of ebrake when doing like a full steering turn around in a parking lot. (To unlock the center diff). There always seemed to be a little lock going on, unless it turned the knob all the way down.

It's instant-there's no perceived delay.

If it was already bound up I'd get a Big "Bang" noise & you could really feel it through the whole driveline (when I pulled the ebrake )
Thanks for the feedback, I will keep testing.

Cedric
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Old 02-22-2019, 10:21 AM   #9
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Ok I did a little test yesterday at the shop. With the rear end completely off the ground with a jack, I was able to climb over 2" thick pieces of wood with the DCCD locked. No sign of slippage, in fact the engine would stall instead if not enough gas was used.

But doing circles on snowy surface I could barely feel the difference. Sure on one hand the snow could affect this, but on the other I think I should be able to feel a difference anyway. Then again, the clutch pulled the car over an obstacle with ease on its own so how much slippage could there be just turning?

I have a Cusco RS rear diff as well, could that affect things?
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Old 02-22-2019, 10:47 AM   #10
point78
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I can tell you there's a big difference how the car slides on a 100% snow packed parking lot withi the diff unlocked vs locked.

Unlocked the the back end goes in more of a big arc vs full lock-where the car does more of a pivot around the center.
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Old 02-22-2019, 12:46 PM   #11
Crazyced
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Quote:
Originally Posted by point78 View Post
I can tell you there's a big difference how the car slides on a 100% snow packed parking lot withi the diff unlocked vs locked.

Unlocked the the back end goes in more of a big arc vs full lock-where the car does more of a pivot around the center.
I wasn't sliding though. Just 1st gear idle speed at full steering lock to see if I could feel binding.
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Old 02-22-2019, 07:52 PM   #12
point78
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Quote:
Originally Posted by Crazyced View Post
I wasn't sliding though. Just 1st gear idle speed at full steering lock to see if I could feel binding.
I know.

Was just another way to feel what/if the center diff was doing.
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Old 03-05-2019, 09:35 AM   #13
Crazyced
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Ok so I did another test last weekend. With the DCCD at open, I got the front wheels against my trailer ramps. I got my rear wheels spinning on sheer ice in 1st gear at 1k rpm. Slowly twisting the knob, the car made it up the ramps at about 30% lockup (assuming the knob is linear).

To me that shows that the clutch is more then strong enough.
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