Torque converter lock up.

Just to shy gave the best description of how the Ram exhaust brake works that I have ever seen. All I have to add is that I am extremely happy with the way it performs. I have used it in Colorado on passes as steep as 11% and always felt in total control. I love it.

Rbertalotto wrote:
On my 2006 Dodge diesel 2500, pulling a 8000 pound trailer. If the torque converter is unlocked, the transmission temp goes from 175 degrees to 200.

Is there a way to keep the converter locked when not in OD?

Tow/haul mode will let it lock in 3rd gear.

On my 2006 Dodge diesel 2500, pulling a 8000 pound trailer. If the torque converter is unlocked, the transmission temp goes from 175 degrees to 200.

Is there a way to keep the converter locked when not in OD?

Thanks guys, great info.

Buddylam,

None of the new automatic transmissions lock the torque converter in first gear, and second gear at 1000rpm does not do much for exhaust braking on any brand. I drive a 2011 F350 6.7 4x4 at work 83,000+ miles, almost all of my driving is in the Sierras, and can honestly say from my experience that the exhuast brake doesn't even compare to working as well as the Ram/Cummins or the GM/Duramax. This isn't a slam on the Ford, it just doesn't work as well as the others until the 2015 model year. The truck in my signature will unlock the torque converter using the ebrake at 20 mph, and does not work below that. The GM/Durmax ebrake works down to about 15 mph in second gear, but as I said, does not hold back much at that low of rpm's.

I previously had a 2007 Dodge 5.9 Cummins Dually with the 6 speed manual (G56) and with the PacBrake exhaust brake. Not even a comparison using the ebrake at low speeds. It worked in first gear all the way to idle speed, which is much lower than any of the automatics first gear, and second gear on the manual is still much lower that the automatics second gear and ebraking was great at slow speeds.

For hiway use such as I-80 for example, with my camper and towing my Jeep, I could go down from Donner Summit to Truckee at about 2100 rpm's and hold speed where I wanted without using the brakes at all on either of the Duallys which both had 3.73's. It was only on the secondary roads at slow speeds that I was actually disappointed with the factory ebrake and automatic.

Just my experience and honest opinion comparing the automatic to the manual. If Hiway driving is the majority of your driving the automatic is really nice. For slow speeds you can't beat the manual for exhuast braking. Also, comparing the horsepower difference between the two, which wasn't as big of a difference as it is with the new trucks, the 5.9 performed great and there wasn't really that much difference pulling the grades with the 6.7. With the new manual trucks having 350 Horsepower, it's not like it's lacking in the power department.

Rich

Drive them all with the transmission you want. I think you will be surprised how well they work, auto or manual.

I have a 99 dodge cummins, automatic. I have a torque converter lock up switch. I use it on hills saving the brakes. Works great.

buddyIam wrote:
I have been inclined to look at the Ram Cummins because of it's manual transmission availability. I always thought it would give better EB on the steep two lane mountain roads that I travel on.

But last night I noticed that the Ford auto can stay locked up down to 900 rpm. If that's true that is about what you would expect from a manual transmission.

Anyone know about the torque converter lock ups on the Chevy and the Ram. Or if any of them work as claimed.

Such as does the Ford 900 rpm apply to any gear?

Well being a RAM owner, here's my experience with the exhaust brake (68RFE transmission):
1. There are 2 modes, Auto and Full-on. When you have it set to Auto, then the exhaust brake will engage whenever your vehicle is accelerating and throttle is not applied (coasting down a hill) or whenever you press the brakes. Under both of these situations, the torque converter must be locked, which means engine speed around 1,000 to 1,100 rpm during lock. Full-on applies the exhaust brake any time you lift your foot off the accelerator and the torque converter is locked.

2. The exhaust brake has slightly different behavior when you are in tow-haul versus no tow-haul. When you are in tow haul, the transmission will continue to down shift as the truck decelerates and re-lock the torque converter and re-engage the exhaust brake with every down shift until you're at about 25 or 30 mph. Without tow-haul, the exhaust brake will only continue to engage until the transmission releases torque converter lockup (around 1,000 to 1,100 rpm) and then the torque converter remains disengaged until the throttle is applied again, then the transmission will re-lock the torque converter once the vehicle is moving quick enough.

So that's how it works on the RAM.

My 2007 Dodge didn't come with an Exhaust Brake.
I added an aftermarket one.

Automatic tranny (48RE) and 5.9L CTD

In Tow/Haul mode, EB ON with 14K 5vr in tow I hold 45 mph on a 6% down grade

Tow/Haul and EB.........better than sliced bread
Newer models I hear are even better

Not sure about the 900 RPM deal. But when in tow/haul, it downshifts at the appropriate time. If RPM's get too low, it downshifts for optimum engine braking. And I really don t need to be concerned about RPM. It's automatic.