48RE + Exhaust Brake: Current Status

[dandlwiley]

RMcColloch: The way you suggested to use the Jake is the way we do it. We don't tow in OD anyway. We drop down to 2nd if the situation calls for it. We only towed once with the new truck last year, so the upcoming season will be the real test. We didn't have any trouble knowing when it was lock or unlocked. Thanks

 

[JRG]

Soon as you take your foot back off after it locks up (3rd) it will come backed un locked. I think that is because the "EB" funtion in the 'puter is disabled from factory.



My only hope is that maybe I can get my PCM replaced or flashed while following up on the new recall, then have my transmission burn up before 70k to get the new upgrades, as my dealer is on the hook.



JRG

 

[Matt400]

Originally posted by JRG

Soon as you take your foot back off after it locks up (3rd) it will come backed un locked. I think that is because the "EB" funtion in the 'puter is disabled from factory.

I bet that particular bit of programing is to meet federal EPA mileage requirements. I haven't looked to see if the TPS is adjustable, you don't suppose a simple adjustment would tell the TCM its off idle and then lock it up longer? Then again messing with that would most likely cause idle trouble.



I will have to pay more attention but if the cut-off is 1600 then for EB use it would be wise to drop into second anyway.

 

[jrobinson2]

Since the OD and lockup are electrically controlled you could tap into the solenoid wire with a small LED light to verify the lockup is engaged when using the engine brake.

Jared

 

[Matt400]

Originally posted by jrobinson2

you could tap into the solenoid wire with a small LED light to verify the lockup is engaged when using the engine brake.

Jared

Thats an excellent idea, it would take allot of concern away for those unsure.

 

[Carlton Bale]

By the way, I spoke with the editor of Trailer Life last week; he owns a Ram with a Cummins engines. There will be a statement in next months magazine stating that the brake is not yet approved for the 48RE.



A far a lockup is concerned; it is definitely difficult to determine when the transmission is actually locked. This is especially true after a downshift during braking, with no throttle applied. On some of our 48RE/exhaust brake test trucks, we have installed an LED just as was mentioned above. This LED only indicates when lockup is commanded, not when it is actually achieved. Detecting actual lockup is one of the planned software changes. There can be problems if the trans is trying to relock and can't because the exhaust brake is activated and the engine speed is too low (as I've discussed previously. ) The LED would be on but the trans wouldn’t be locked.

 

[RMcCulloch]

One [I think] good way to spot the TC unlock is to keep an eye on the tach: the engine speed will suddenly drop to idle when it unlocks.



When that happens, I either disengage the EB, "goose" the throttle to cause lockup again, or downshift (with a "goose") depending upon the circumstances.



Although, usually, the decelleration provided by the service brakes and drivetrain are adequate even at 23K combined, the EB does a wonderful job - especially when dealing with abrupt speed change requirements.

 

[brillmtb]

If you use one of the advertised aftermarket TC (ie triple loc) and the electronic TC control unit and put them in an 03 will that make the truck safe to use with an EB?



I realize your warrently might be void but is there anything else the truck needs to functionally be EB capable.

 

[RMcCulloch]

Given the nature of the problem of the thrust washer, I'm not so sure that I want to be the one to try it.



Given the way that the 48RE acts without the EB, I might be asking for even more problems than those I already face.



Consider: if the primary failure is the result of unpowered retardation, then forcing lockup will simply compound the issue.



As it is, I'm hoping that infrequent use of the exhaust brake [only when actually needed] won't be a major factor in any potential transmission.



With any luck, I'll be able to avoid the problem and, if not, blame it upon the use of OD when towing.

 

[JRG]

Carlton,



Thanks for staying on top of this. I was wondering what you thought of the possible replacement of the PCM/harness under the '03 recall. Would this have and/or be able to be updated to the new program needed for EB use in an '03? (minus the hardware upgrades of coarse)



JRG

 

[ACerf]

E brake

I guess I am kind of a worry wort. But if installing anything that helps make the Trans stay in Lockup seems okay, until that unit fails! This may in turn cause damage to the trans! If you are willing to take that risk, I guess it is that is the chance one takes!

The other problem is, does DC really know what or if the trans would fail using an EB and under what conditions need to be present for this to happen? I keep reading so many different threads about the subject, that I am beginning to wonder if DC is just like me... worry worts!



Another thought; If companies can come out with gadgets that can lockup the trans... given the fact that it is necessary. Why couldn't DC come out with one themselves? This would solve the problem for us and them! Which leads me back to, do they really have a handle on the problem? Seems to me that DC is making this a bigger deal than it really is, if they would just step up the plate and fix the problem! As well as, giving the early 2003-2004 a fix! Maybe Carlton can answer these questions.

 

[Matt400]

Re: E brake

Originally posted by ACerf

Another thought; If companies can come out with gadgets that can lockup the trans... given the fact that it is necessary. Why couldn't DC come out with one themselves? This would solve the problem for us and them! Which leads me back to, do they really have a handle on the problem? Seems to me that DC is making this a bigger deal than it really is, if they would just step up the plate and fix the problem! As well as, giving the early 2003-2004 a fix! Maybe Carlton can answer these questions.

As for the other companies products, remember this quote?



Carlton wrote:

There is a lot more to locking up the torque converter than sending a lock-up signal. During development, we datalogged a very frequent situation during exhaust braking where the lockup signal was sent but, due to the differential in engine speed and transmission speed, the converter would not actually lock. This is a very bad condition because the trans is devoting all fluid flow to build pressure to lock the torque converter. Until it locks, there is no cooling of the transmission fluid. This is OK for short periods of time but if the trans stays in the "lock commanded but still unlocked mode", it will get very, very hot inside the trans (not in the trans pan where the temp sensor is. )



Banks may offer a lockup kit, but I bet they don't offer any type of warranty on the transmission. Durability is not their primary goal. I have no authority to explain the DaimlerChrysler warranty, but I don't think you'll ever see a Banks-style lockup device approved.



As I stated previously, we are working to develop software that commands lockup in conditions where it can actually be achieved and also monitors various speed sensors to make sure lockup is achieved. There is currently no third-party lockup device that can do this or anything even close to this.

While the above covers the software side, Carlton also mentioned the hardware issue that is being worked on-



Carlton wrote:

I know that DaimlerChrysler engineering is also working to revise one or more thrust washers within the transmission to be sure that they can withstand the reverse-torque encountered during exhaust braking.

I for one am interested to see the final outcome, who knows the next 48RE might be the one to judge all others by. Those of us that didn't make it- well... just didn't make it.



Its very possible that what engineering is doing now will pave the way for future upgrades when/ if rebuild time comes. Did they release the 48 too soon? well if so then we would all be running 47's and I for one would rather have my 48.

 

[ACerf]

E brake

It would seem to me that if GM (aka Allison) and Ford can make a trans that can handle a E-Brake, so could DC. I would rather have the Cummins engine over the othe two. But I think DC has gotten off on the wrong foot with there transmissions in general. In other words not thought out! They knew most people who where going to buy the 03 with the auto, where going to want an E-brake, I know I did! That is what happens when you are in hurry to get something out there to the public! But now the best anyone can hope for is that a late 2004 or 05 will have the benefit of the E-brake. I told my field rep the other day, that DC screwed the 03 and 04 folks... and he somewhat agreed!

 

[t6_man]

Re: Re: E brake

Originally posted by Matt400

Did they release the 48 too soon? well if so then we would all be running 47's and I for one would rather have my 48.

Amen!!!

 

[Carlton Bale]

Originally posted by JRG

I was wondering what you thought of the possible replacement of the PCM/harness under the '03 recall. Would this have and/or be able to be updated to the new program needed for EB use in an '03? (minus the hardware upgrades of coarse)

JRG, the software change for the exhaust brake would be for the control module mounted on the engine. This could only be done for 2004 and later vehicles with the transmission controls integrated into the engine control module.



I'm not sure if GM and Ford transmissions can handle exhaust brakes but I'm fairly sure that their engines can't. At least not like the Cummins engine can. Their engines both use hydraulic lash adjusters so if valves start to float during braking, the lash changes, and the valve won't fully close. So, the Cummins engine can handle higher backpressures and produce more braking power.

 

[Matt400]

Originally posted by Carlton Bale

I do believe that the software would be made available for older vehicles even though warranty approval would not due to hardware changes. This could only be done for 2003. 5 and later vehicles with the transmission controls integrated into the engine control module.

Don't you mean the 2004's where there is only the one controller vs those 03's that have separate engine and trans modules?

I don't understand why the 03 48RE's are referred to as 03. 5. My truck was built on 01/03 and has the 48.

 

[Carlton Bale]

Originally posted by Matt400

Don't you mean the 2004's where there is only the one controller vs those 03's that have separate engine and trans modules?

I don't understand why the 03 48RE's are referred to as 03. 5. My truck was built on 01/03 and has the 48.

Matt, my mistake. You are absolutely right, 2004 started the common controller, not 2003. 5.



Generally, changes occur at each half model year. MY2003 production started in July, 2002 with the 47RE. MY2003. 5 production started in January, 2003 with the 48RE. Half-model year changes are generally used for option/build changes. The new 'Cummins 600' engine was a half model year introduction: 2004. 5.

 

[ACerf]

Originally posted by Carlton Bale

JRG, the software change for the exhaust brake would be for the control module mounted on the engine. I do believe that the software would be made available for older vehicles even though warranty approval would not due to hardware changes. This could only be done for 2004 and later vehicles with the transmission controls integrated into the engine control module.



I'm not sure if GM and Ford transmissions can handle exhaust brakes but I'm fairly sure that their engine can't. At least not like the Cummins engine can. Their engines both use hydraulic lash adjusters so if valves start to float during braking, the lash changes, and the valve won't fully close. So, the Cummins engine can handle higher backpressures and produce more braking power.

I am not sure about the Ford or GM engines, but you have to admit that both of them have made good transmission choices. Well at least GM anyway! I think the jury is still out on the Ford trans. My experience with Ford, they don't always have a "Better Idea"! My new saying is "Serious Pickups Have A Cummins Diesel"!

 

[brillmtb]

CB,



My tech told me that the 03 TC is locked up in manual 3rd and 2rd and that an EB would work and they have put them in.



A friend of mine, engineer, spoke to an engineer inside DC and was told that the reason for no EB approval on 03 was not that it couldnt safely be done but that the user could manually unlock the TQ (probably by hitting the OD button off and on based on what the local tech told me) and that was the real reason. They wanted the TQ lockup NOT to be under the control of the driver for approval so that it could not be manually changed to a setting that would cause problems.



Besides other things that have come out on this washer wearing does this sound correct to you?

 

[Cliffman]

guys, I'm looking at buying my wife a truck. I'm a six speed man but the better half perfers an auto. I really don't feel like reading this intire thread. What's the bottom line with the E-break for the new 04. 5's