68rfe transmission -exhaust brake operation

[chewchoo]

hello TDR People-

Please forgive my first attempt at posing a problem - maybe it's a sign that I have had no probs with my first 2 trucks that I could not cope with !!



I have had a 95 which had the 5 speed to which I added a BD brake (and a lot of power). That brake worked wonderfully. My second ram was a 05 with the g56 6speed. (and a little power) That BD brake worked almost as well -after I relocated the compressor (mounted it on rubber on the tranfer case skid plate).



My third ram is new last week - after reading issue 57 pages 52 and 53 I confess I was drawn to my favorite dealer like a magnetic force was in control of my checkbook !!



The problem is that per the owners manual and the info in issue 57 this brake is not operating as I (would like it to) think it should.



For example - when slowing down from about 60 (or more ) mph - transmission in 6 (or auto 6) - the brake works, until I get to 42 mph and then has no retarding force down to stop. I think that 42 mph maybe is when the first downshift occurs ?



If I have it in tow/haul the same thing happens at about 32 mph.

Is this normal ? Is this because the torque converter loses lockup ?



If I select lower gears the same thing occurs - at corresponding lower speeds.

Also I have seen another undesirable situation - when descending a long, variable grade in gear 3 - everything going as expected - until the grade lessened and I touched the throttle until the grade dropped again - released the throttle but had no retarding force - nada none ! !



I am not going to like this when I'm hauling the horse trailer in the mountains! ! ! I am accustumed to being able to descend high passes without ever using trailer or truck brakes - just exhaust brakes - saving regular brakes for emergencies.



Of course I am taking the truck to the dealer tuesday 10/23 but if any of you have any input I would like to know if there are any solutions or suggestions? ? ? Is this a problem ? or is this "norrmal"?



Is the trans control Module ok ? or is the turbo/brake ok?



Your input would be greatl appreciated ! ! Thank you ! !

 

[HBarlow]

Chewchoo,



A completed signature on your post would be helpful to members who wish to answer your question.



Does your truck have the standard 3. 73 differential or the optional 4. 10? It makes a difference in perceived braking force you can expect from the exhaust brake.



Does your truck have an on/off switch for the exhaust brake?



I don't have specific experience or knowledge of a 2007 beyond a couple of test drives so I'll describe my own truck.



My 2006 Ram with 48RE four speed automatic and Jacobs exhaust brake, will provide exhaust braking from whatever speed down to 40 mph when the computer momentarily disengages the exhaust brake, downshifts the transmission to third gear, then reengages the exhaust brake. Braking continues down to 20 mph when the torque converter unlocks and the exhaust brake deactivates. From 20 mph the truck coasts. If the exhaust brake switch is in the off position this doesn't happen. I think the 2007 operates the same way.



Harvey

 

[Simplysmn]

Chewchoo,



If you are going down a hill with a load I am sure the brake will work under a load just as good at your past trucks unloaded yes as you wrote it will act like it does now but have you tryed it underload yet ? If you need to get to a slower speed drop a gear with the exhaust brake on . I will also try this with my 08 on tuesday as I will be towing and see what I can find also .

 

[captaindean]

the exhaust brake will shut off at 1100rpm at least that is what mine is doing

there was a post that talked about this. dont remember where this was hope this helps.

 

[Jeepstang]

I think mine with the tow haul mode and the eb on works until it's only going a few MPH then it releases. on the hwy it seems to hold until i press on the gas pedal. with only the eb on it;s not very aggressive

 

[TKeeler]

hello TDR People-

Please forgive my first attempt at posing a problem - maybe it's a sign that I have had no probs with my first 2 trucks that I could not cope with !!



I have had a 95 which had the 5 speed to which I added a BD brake (and a lot of power). That brake worked wonderfully. My second ram was a 05 with the g56 6speed. (and a little power) That BD brake worked almost as well -after I relocated the compressor (mounted it on rubber on the tranfer case skid plate).



My third ram is new last week - after reading issue 57 pages 52 and 53 I confess I was drawn to my favorite dealer like a magnetic force was in control of my checkbook !!



The problem is that per the owners manual and the info in issue 57 this brake is not operating as I (would like it to) think it should.



For example - when slowing down from about 60 (or more ) mph - transmission in 6 (or auto 6) - the brake works, until I get to 42 mph and then has no retarding force down to stop. I think that 42 mph maybe is when the first downshift occurs ?



If I have it in tow/haul the same thing happens at about 32 mph.

Is this normal ? Is this because the torque converter loses lockup ?



If I select lower gears the same thing occurs - at corresponding lower speeds.

Also I have seen another undesirable situation - when descending a long, variable grade in gear 3 - everything going as expected - until the grade lessened and I touched the throttle until the grade dropped again - released the throttle but had no retarding force - nada none ! !



I am not going to like this when I'm hauling the horse trailer in the mountains! ! ! I am accustumed to being able to descend high passes without ever using trailer or truck brakes - just exhaust brakes - saving regular brakes for emergencies.



Of course I am taking the truck to the dealer tuesday 10/23 but if any of you have any input I would like to know if there are any solutions or suggestions? ? ? Is this a problem ? or is this "norrmal"?



Is the trans control Module ok ? or is the turbo/brake ok?



Your input would be greatl appreciated ! ! Thank you ! !

As long as the RPM is above 1100 and in a gear higher than 2nd mine works everytime I let off the throttle as long as I have turned on the switch.



Go to this thread... https://www.turbodieselregister.com...2007-5/188670-run-exhaust-brake-all-time.html

 

[jelag]

HBarlow has the operation down well... We install PacBrake and we see the same operation... Based on the year... Both the PacBrake and the Jacobs units interface with the ECM the same way... and would function the same way... .

What I've learned from hundreds of sales and installations is that not all trucks have the same software to run the brake... let me try and explain...

my 05 with the 6 speed will leave the brake on until the truck comes to a complete stop and about 10 seconds after the complete stop the ecm shuts down the brake... the only time it will run at idle and at a stop is on a fresh start up and warm up... .

My 04 with the 6 speed, will leave the brake on all the time while at rest... . cold, hot, what ever... .

The programing on the autos seems to be different from year to year as well... but I don't own one, so I'm not as strong on my knowledge on them... my experience is the test drive after installation...

I have not found a dealer that understands the software and the way the ECM runs the exhaust brake function... . for them its either working or not. .

Hope this helps... .

 

[BDW]

I have a 2007. 5 with the factory brake. It seems to work down to about 20 mph. Not sure if it is rpm or mph that triggers it off but, it doesnt seem to matter how many times I'm on and off the gas pedal it brakes every time. I have noticed that the brakeing force is a lot greater in the Tow/Haul mode.





Sig still says 06 but last week I traded it in on an 07. 5.

 

[Garlic]

My 07. 5 with the 68RFE the EB works great, loaded or unloaded. Definitely in T/H better. It will shut off at about 20 MPH or around 1000 rpm in my application. If you activate the service brake, not apply, it will begin to down shift to keep the rpm's over 1700, The more aggressively you apply the service brake the EB appears to be more aggressive. I have 3000 + miles towing in up and around southern Colorado with 11K hooked to the king pin and rarely have to use the service brake hard. The Prodigy controller that I use also helps with this because the brake lights are on and the slowing force activates the trailer brakes. It does take time to figure out how it best suits your personal needs. I have installed and sold numerous BD and Banks EB kits and I feel that the factory EB has the best feel and function paired with the 68RFE of all of them I have installed.

 

[TKeeler]

My 07. 5 with the 68RFE the EB works great, loaded or unloaded. Definitely in T/H better. It will shut off at about 20 MPH or around 1000 rpm in my application. If you activate the service brake, not apply, it will begin to down shift to keep the rpm's over 1700, The more aggressively you apply the service brake the EB appears to be more aggressive. I have 3000 + miles towing in up and around southern Colorado with 11K hooked to the king pin and rarely have to use the service brake hard. The Prodigy controller that I use also helps with this because the brake lights are on and the slowing force activates the trailer brakes. It does take time to figure out how it best suits your personal needs. I have installed and sold numerous BD and Banks EB kits and I feel that the factory EB has the best feel and function paired with the 68RFE of all of them I have installed.

Traveling down a 6% grade with 7,000+ lb travel trailer and load in the truck bed with the Tow/Haul switch and EB on I actually have to use the throttle occasionally to keep from slowing down too much. :-laf If you do need to apply the truck brakes hang on as the transmission in Tow/Haul mode does some serious down shifting. With the way this EB and transmission work together the trailer brakes hardly ever get touched. Oo.



I turn the EB on every time I start up the truck, it works excellent. After driving with this EB I wouldn't have another truck without one.