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CampingN_C_'s avatar
CampingN_C_
Explorer
Nov 04, 2015

Ram exhaust brake at slow speeds.

This issue was brought up in another tread and I didn't want to hijack it so..
On our first trip out with the new TV we went to the NC mountains...of course :B. Going up the 6-7 % grade was awesome to say the least. However, coming down didn't necessarily meet my expectations.
Now this was Hwy 226 for all you locals reading. Very twisty and slow speeds. By twisty I mean it was hard to stay in my lane on some curves.
I thought the EB would easily hold me coming down but I'm pretty sure it wasn't on. I had to keep stabbing the brakes to keep the speed down. RPM's were approaching 3K, close to redline. I wasn't really watching the speedo but I'd guess around 15-20 mph. I had it set on auto, should I have set it on full? Or will it just not work that slow.
  • Grit dog wrote:
    Just a guess but 3krpms and 15mph sounds like first gear. Idk if the TC will lock in first and the EB typically won't engage if the TC is unlocked.


    Bingo! Same deal on the DMax trucks if in 1st gear. TC wont lock.
  • Manually gear down to as low as 2nd with EB on FULL and TH on. For example I pull a lot of 6% grades in 4th gear so when cresting the grade and going to be heading down I select 4th so it holds the gear and place the cruise at 55. it will hold most grades but some are a bit steeper so I may have to apply the service brakes to bring it back to 55 and then hit the set/cruise button and repeat.

    I have 4:10's and 32,500 combined weight. So with 3:42's I would have used 3rd gear. The EB works better the higher the RPM's are.
  • Just a guess but 3krpms and 15mph sounds like first gear. Idk if the TC will lock in first and the EB typically won't engage if the TC is unlocked.
  • Full or auto depends on your goal. If you're trying to slow down, full. If you're trying to maintain, auto. A great example that I tow on is a long major grade that leads right into a small town. I have it on auto going down the grade and it holds speed like cruise control once I tap the brakes. Then near the bottom of the hill you switch to full to slow down headed into town. It takes an amazing workload off the brakes.

    If you're only going 15 mph I'm not sure the exhaust brake is going to do much either way, though.
  • CampingN.C. wrote:
    This issue was brought up in another tread and I didn't want to hijack it so..
    On our first trip out with the new TV we went to the NC mountains...of course :B. Going up the 6-7 % grade was awesome to say the least. However, coming down didn't necessarily meet my expectations.
    Now this was Hwy 226 for all you locals reading. Very twisty and slow speeds. By twisty I mean it was hard to stay in my lane on some curves.
    I thought the EB would easily hold me coming down but I'm pretty sure it wasn't on. I had to keep stabbing the brakes to keep the speed down. RPM's were approaching 3K, close to redline. I wasn't really watching the speedo but I'd guess around 15-20 mph. I had it set on auto, should I have set it on full? Or will it just not work that slow.


    You should have it on full. In the Auto mode it only tries to hold a speed at which you set by tapping the brake pedal. Also at that slow of speed (below 20) it will not react as fast as you would like it to and will not work below about 12 MPH (that's the lowest I've had mine to work). With the RPM at 3K , you would definitely know if it was working or not. The exhaust brake is not designed to stop you just to assist in a stop or help hold speed on a hill. At 15-20 MPH your brakes should be all you need and if they won't do it then you are overloaded or you have a brake problem. The computer senses acceleration and deceleration and has preset to certain specs. If you are coming up to a curve and you apply a lot of brake pressure and the truck starts to slow down quickly the exhaust brake will not come on or it will go off if is on and you start to slow down faster than the preset. Also I have found that if I want it to work below 20 I have to manually shift it to a lower gear and leave it. Once you get to a gear that the torque converter unlocks (2nd gear I believe is the lowest gear to lock) the exhaust brake will not come on.

    This is another plus for the hand shaker transmission. It will work in all gears. My 2010 6 speed would almost stop you if you went to 1st gear. It would work down to an idle.

    Next time try full on in TH mode and lock it in second gear.
  • Run the transmission in tow/haul mode with full exhaust braking. The ratios are different in my Aisin transmission plus I have higher axle gear ratios, so maybe my truck gets more engine braking benefit. Do not shift the automatic transmission into first gear since it cannot lock up the torque converter and effectively use exhaust braking.
  • Combination of EB and transmission shifted to a lower gear does wonders.
  • I run mine on the first push of the button. Second push of the button lets the exhaust brake activate when the brake pedal is pushed. I then also manually shift to lower gears on the shifter handle. It should have been roaring as in BAAAAWWAAAAAAAAAAAAA