Exhaust brake for 03 and early 04 auto trucks
Registered User
Joined: Jan 2004
Posts: 415
Likes: 0
From: Chestermere, Alberta, Canada
Shifting with the converter locked is definitely going to cause a pretty harsh shift. Now depending on what kind of power and what is done to your tranny sometimes you can get away with it, and in some cases it can break things. You don't have to run with the converter constantly locked to use an exhaust brake. There are controllers out there that will only lock the converter when you use the exhaust brake. That would be a better option than letting it shift locked up..
DTR Advertiser
Joined: Mar 2005
Posts: 816
Likes: 1
The Pacbrake controller locks and unlocks the tq conv as needed. But in some cases with the throttle not achieving 35% to disengage the tq converter (with say Smarty 100HP) you may indeed have 2nd gear shift with the tq converter locked. Now this is not ideal when pulling 17000lb. It would be nice if the controller was set at 5%. That will not happen since the Pac has seen tq conv hunting at under 35% which i don't quite get. What other controller works like this but maybe better ??????
Registered User
Joined: Jan 2004
Posts: 415
Likes: 0
From: Chestermere, Alberta, Canada
Okay Pat,
When you say you can dial it in, can you program say 5% throttle position ? If this is true do you see torque converter lock up hunting ? If not why does the competitions controller hunt ? Curious
When you say you can dial it in, can you program say 5% throttle position ? If this is true do you see torque converter lock up hunting ? If not why does the competitions controller hunt ? Curious
DTR Advertiser
Joined: Mar 2005
Posts: 816
Likes: 1
I am not quite sure what you mean about 5%. We have a setting that allows you to program a percentage of throttle application to allow the converter to unlock easing the load on the lockup clutch, but I dont think that is what you are looking at.
When we command the converter to lockup it will stay locked up with out hunting until you get to the set release rpm. Then depending on what gear you are in it will either downshift or if you are in 2nd gear already it will release the lockup.
Registered User
Joined: Jan 2004
Posts: 415
Likes: 0
From: Chestermere, Alberta, Canada
Yes i'm talking about 5% throttle. I hear anything below 35% throttle on the Pacbrake auto controller (for 03-04 trucks with 48RE), you start getting torque converter hunting which i just don't understand and no one seems to have answers ? I think you should be able to have the ECM take control of the TQ conv lock up the second you get on the throttle. The Pacbrake (for my 04 48re) does not let the tq conv unlock until 35% throttle which can be a pita when the truck shifts say from 2nd to 3rd etc. They can reprogram the controller but they warn against the tq conv hunting. I know Georend, DTT etc have been trying to come up with a better solution. It seems like most guys are running a mystery switch but i just don't know if that is the right solution. How does the BD controller work ? Ideas ?
DTR Advertiser
Joined: Mar 2005
Posts: 816
Likes: 1
With either our Torqloc which operates off speed or our Towloc which operates off of rpm for cutout, the module has complete control of lockup. Very much like a mystery switch, but with a cutout. We don't use a percentage of throttle disengagement. When the pedal returns to idle and the torqloc is functional with the brake it will hold the converter locked until you hit the cut out speed. With the towloc it is basically the same, except it is using a programmed rpm to drop lockup.
Registered User
Joined: Jan 2004
Posts: 415
Likes: 0
From: Chestermere, Alberta, Canada
Pat, i get the throttle cut out part, which is when the trq conv locks and brake comes on part. But how does the rpm engagement piece work for tq conv unlock work. Every grade is different and with a downdshift rpm can and will increase. Would a certain rpm un lock the tq conv if your navigating a steep decent with a downshift and rpm increase. Sorry just trying to understand it in my head. Is it possible to contact you about this. It seems like the keyboarding surfing is taking to long, LOL
DTR Advertiser
Joined: Mar 2005
Posts: 816
Likes: 1
Pat, i get the throttle cut out part, which is when the trq conv locks and brake comes on part. But how does the rpm engagement piece work for tq conv unlock work. Every grade is different and with a downdshift rpm can and will increase. Would a certain rpm un lock the tq conv if your navigating a steep decent with a downshift and rpm increase. Sorry just trying to understand it in my head. Is it possible to contact you about this. It seems like the keyboarding surfing is taking to long, LOL
Registered User
Joined: Jan 2004
Posts: 415
Likes: 0
From: Chestermere, Alberta, Canada
I wanted to start a new post on the BD forum but i don't have privy yet. I have the following questions after reading the manuals:
1. How does the cruise work. I know it does not stay engaged etc. When you hit the brake or hit cancel (cruise) does the trq lock up and brake engage etc.
2. Also i know you get a 4 to 3 shift with the Tow Loc but what about 2nd ?
3. I see there is a setting for TQ conv release at say 80-85% Is this the setting that actually release the brake ???? I thought (i might just not be looking at it right) the brake was released and Tq conv unlocked as soon as the throttle was re applied.
4. What is the purpose of Auto Loc if it is the same thing more or less as Tow Loc.
5. With the parameters what is the lowest speed you can have the brake engaged at etc.
6. How does the 2004 tow haul fit into this ?
6. So in general when i let off the throttle the tq conv will lock and brake engages. If it needs to down shift, the tq conv unlocks and shifts and then re locks. When i get back on the throttle (1% throttle etc) the brake turns off and the tq conv unlocks.
So i do not have issues like tq conv lock up during a shift while getting back on the gas, like the PacBrake unit possibly could.
Sorry for all the questions but it seems like the year really affects your final outcome, LOL
1. How does the cruise work. I know it does not stay engaged etc. When you hit the brake or hit cancel (cruise) does the trq lock up and brake engage etc.
2. Also i know you get a 4 to 3 shift with the Tow Loc but what about 2nd ?
3. I see there is a setting for TQ conv release at say 80-85% Is this the setting that actually release the brake ???? I thought (i might just not be looking at it right) the brake was released and Tq conv unlocked as soon as the throttle was re applied.
4. What is the purpose of Auto Loc if it is the same thing more or less as Tow Loc.
5. With the parameters what is the lowest speed you can have the brake engaged at etc.
6. How does the 2004 tow haul fit into this ?
6. So in general when i let off the throttle the tq conv will lock and brake engages. If it needs to down shift, the tq conv unlocks and shifts and then re locks. When i get back on the throttle (1% throttle etc) the brake turns off and the tq conv unlocks.
So i do not have issues like tq conv lock up during a shift while getting back on the gas, like the PacBrake unit possibly could.
Sorry for all the questions but it seems like the year really affects your final outcome, LOL
DTR Advertiser
Joined: Mar 2005
Posts: 816
Likes: 1
I wanted to start a new post on the BD forum but i don't have privy yet. I have the following questions after reading the manuals:
1. How does the cruise work. I know it does not stay engaged etc. When you hit the brake or hit cancel (cruise) does the trq lock up and brake engage etc.
If your cruise is on and active, when the brake operates it will cancel cruise control. Cruise is disabled as a safety so you dont have the brake slowing you down and cruise speeding you up.
2. Also i know you get a 4 to 3 shift with the Tow Loc but what about 2nd ?
Yes it will make a down shift into 2nd as well.
3. I see there is a setting for TQ conv release at say 80-85% Is this the setting that actually release the brake ???? I thought (i might just not be looking at it right) the brake was released and Tq conv unlocked as soon as the throttle was re applied.
This is for acceleration only. It is there to help protect a torque converter. The exhaust brake isnt activated when this function activates.
4. What is the purpose of Auto Loc if it is the same thing more or less as Tow Loc.
That is the position you would want to leave it in for exhaust brake use. This way when it is in the autoloc position every time the accelerator goes back to idle the brake comes on.
5. With the parameters what is the lowest speed you can have the brake engaged at etc.
Typically you can go down to about 13-15mph. That is about the lowest it will generate useable back pressure.
6. How does the 2004 tow haul fit into this ?
The tow haul button on yours is nothing more than an OD off button. The towloc will know if you are in od or not and will respond accordingly.
6. So in general when i let off the throttle the tq conv will lock and brake engages. If it needs to down shift, the tq conv unlocks and shifts and then re locks. When i get back on the throttle (1% throttle etc) the brake turns off and the tq conv unlocks.
Almost correct here. When you step back on the throttle the converter most likely wont unlock. It just reverts back to the pcm controlling it.
So i do not have issues like tq conv lock up during a shift while getting back on the gas, like the PacBrake unit possibly could.
No issues like that at all.
Sorry for all the questions but it seems like the year really affects your final outcome, LOL
1. How does the cruise work. I know it does not stay engaged etc. When you hit the brake or hit cancel (cruise) does the trq lock up and brake engage etc.
If your cruise is on and active, when the brake operates it will cancel cruise control. Cruise is disabled as a safety so you dont have the brake slowing you down and cruise speeding you up.
2. Also i know you get a 4 to 3 shift with the Tow Loc but what about 2nd ?
Yes it will make a down shift into 2nd as well.
3. I see there is a setting for TQ conv release at say 80-85% Is this the setting that actually release the brake ???? I thought (i might just not be looking at it right) the brake was released and Tq conv unlocked as soon as the throttle was re applied.
This is for acceleration only. It is there to help protect a torque converter. The exhaust brake isnt activated when this function activates.
4. What is the purpose of Auto Loc if it is the same thing more or less as Tow Loc.
That is the position you would want to leave it in for exhaust brake use. This way when it is in the autoloc position every time the accelerator goes back to idle the brake comes on.
5. With the parameters what is the lowest speed you can have the brake engaged at etc.
Typically you can go down to about 13-15mph. That is about the lowest it will generate useable back pressure.
6. How does the 2004 tow haul fit into this ?
The tow haul button on yours is nothing more than an OD off button. The towloc will know if you are in od or not and will respond accordingly.
6. So in general when i let off the throttle the tq conv will lock and brake engages. If it needs to down shift, the tq conv unlocks and shifts and then re locks. When i get back on the throttle (1% throttle etc) the brake turns off and the tq conv unlocks.
Almost correct here. When you step back on the throttle the converter most likely wont unlock. It just reverts back to the pcm controlling it.
So i do not have issues like tq conv lock up during a shift while getting back on the gas, like the PacBrake unit possibly could.
No issues like that at all.
Sorry for all the questions but it seems like the year really affects your final outcome, LOL
Registered User
Joined: Jan 2004
Posts: 415
Likes: 0
From: Chestermere, Alberta, Canada
6. So in general when i let off the throttle the tq conv will lock and brake engages. If it needs to down shift, the tq conv unlocks and shifts and then re locks. When i get back on the throttle (1% throttle etc) the brake turns off and the tq conv unlocks.
Almost correct here. When you step back on the throttle the converter most likely wont unlock. It just reverts back to the pcm controlling it.
This happens instantly with a small amount of throttle ?
Thanks
Almost correct here. When you step back on the throttle the converter most likely wont unlock. It just reverts back to the pcm controlling it.
This happens instantly with a small amount of throttle ?
Thanks
DTR Advertiser
Joined: Mar 2005
Posts: 816
Likes: 1
6. So in general when i let off the throttle the tq conv will lock and brake engages. If it needs to down shift, the tq conv unlocks and shifts and then re locks. When i get back on the throttle (1% throttle etc) the brake turns off and the tq conv unlocks.
Almost correct here. When you step back on the throttle the converter most likely wont unlock. It just reverts back to the pcm controlling it.
This happens instantly with a small amount of throttle ?
Thanks
Almost correct here. When you step back on the throttle the converter most likely wont unlock. It just reverts back to the pcm controlling it.
This happens instantly with a small amount of throttle ?
Thanks
Registered User
Joined: Jan 2004
Posts: 415
Likes: 0
From: Chestermere, Alberta, Canada
Sweet. Sounds like this is the ticket. Will be in touch Pat. Thanks for all the great information thus far. Its nice to see some customer service out there, although i'm not a customer yet, LOL. Will be shortly, though.
C
C
Thread Starter
Registered User
Joined: Aug 2002
Posts: 8,803
Likes: 0
From: Northern Virginia
Any 03-04 owners running an E-Brake without replacing the aforementioned thrust washer? Any issues with your trans? I want an E-Brake badly but if I have to pull the trans to replace that washer then there would be no question that I also upgrade the internals. The problem is that I really can't afford to do all that right now. Any opinions???