Grade Gripper

[steve r]

Have a 2016 CHU when its been wet from rain the ABS and ATC lights will come on the code Im getting is for the ABS left 2nd axle wheel . When its below freezing the grade gripper sticks  even when you have the switch disengaged . I have changed the grade gripper solenoid but it is still doing it. This dosnt happen all the time but when it does its always cold and wet. I have put my foot under the brake pedal and picked up on it and it has released not sure if it was coincidence its not sticking enough times for me to see if the problem is in the foot valve When it is stuck the brake lights are not on dont know if that rules out stuck brake pedal. Any ideas Thanks

Edited February 29 by steve r

[mowerman]

Sounds like a ground problem to me. Also, I would change that treadle valve they are very easy to get. Good luck.bob

[fjh]

if it were the griper you would think all the brakes would stick! Modulator valve comes to mind here for me! Try some brake line antifreeze !

[steve r]

Thank you for the reply I came across an article showing the plastic vent on the bottom of the  grade gripper solenoid. It says it can get wet and freeze this would make the brakes not release. Truck just got back to yard the plastic vent was froze over . Cleaned and reinstalled hand tight if and when it acts up again will unscrew it and see if that does it Will follow up if it works or not Thank you

[mechohaulic]

2016 is way too new of a unit for me ; but have to ask :: what is a grade gripper  associated to brake system/pedal ?? also where in CT are you located ?? 

[steve r]

In Enfield from what I understand the grade gripper is on auto trannys it  is tied into the ABS system the tranny and air system

like you this is to new a unit for me to understand. 

[fjh]

4 minutes ago, steve r said:

In Enfield from what I understand the grade gripper is on auto trannys it  is tied into the ABS system the tranny and air system

like you this is to new a unit for me to understand. 

Correct! its all inter connected when the Mdrive is used!

[Joey Mack]

Mech,  grade gripper replaces the driver using his trolley as a hill holder.. just more crap.  

[steve r]

You are right sir so many electronics on these things have a couple newer Freightliners also every time it rains something goes wrong. 

[fjh]

9 minutes ago, Joey Mack said:

Mech,  grade gripper replaces the driver using his trolley as a hill holder.. just more crap.  

Layers of it Joey! They had to implement this or the 10000 dollar clutch would burn up! As much as this trans works amazingly well when it screws up its pricey ! Provided all is working in harmony all is good! BUT if anything is out of tune get your wallet out ! I stopped by the shop last week the boys were doing an Mdrive clutch and front section re and re as it was to expensive for us to replace and input bearing they exchange the main box! Parts changing not mechanicing

[67RModel]

2 hours ago, mechohaulic said:

2016 is way too new of a unit for me ; but have to ask :: what is a grade gripper  associated to brake system/pedal ?? also where in CT are you located ?? 

It is a new age nanny device to help "drivers" who don't really know how to drive a manual transmission actually drive a manual transmission. It keeps air pressure applied to the service brakes for a period of 2-3 seconds after releasing the foot valve. This is supposed to give someone time to get their right foot over to the throttle and start giving the truck fuel and not roll backwards if stopped on an incline. Hence the name "grade gripper" 🙄

Edited February 29 by 67RModel

[fjh]

2 hours ago, Joey Mack said:

Mech,  grade gripper replaces the driver using his trolley as a hill holder.. just more crap.  

Layers of it Joey! They had to implement this or the 10000 dollar clutch would burn up! As much as this trans works amazingly well when it screws up its pricey ! Provided all is working in harmony all is good! BUT if anything is out of tune get your wallet out ! I stopped by the shop last week the boys were doing an Mdrive clutch and front section re and re as it was to expensive for us to replace and input bearing they exchange the main box! Parts changing not mechanicing

 

35 minutes ago, 67RModel said:

It is a new age nanny device to help "drivers" who don't really know how to drive a manual transmission actually drive a manual transmission. It keeps air pressure applied to the service brakes for a period of 2-3 seconds after releasing the foot valve. This is supposed to give someone time to get their right foot over to the throttle and start giving the truck fuel and not roll backwards if stopped on an incline. Hence the name "grade gripper" 🙄

Yep ! the New Age! If you stomp to hard to fast it will likely  derate on you 🙄! 

[67RModel]

I guess now that I think about it I'm not sure if the grade gripper is for trucks with a manual transmission or if its specific only to trucks with the M-Drive automated manual. I don't really know. It has to be a part of the M-Drive system so the air actuated clutch can engage smoothly without the truck rolling backwards. Perhaps its also a part of a manual setup now as well. Somebody more familiar with the new stuff will probably know. My passenger car with 5 speed manual has the same technology and its super annoying if you actually know how to drive a manual....

[Joey Mack]

M drives

[mowerman]

I didn’t know what it was either our trucks you can step on the brakes real hard and brakes will stay engaged to check service lines works well for triples lotsa lines to check… bob

[tjc transport]

same here, did not know what it is. 

is the M drive like the eaton fuller ultrashift where it is a automatic clutch controlled by the computer? 

my friend had two trucks with the 10 speed ultrashift. after replacing the clutches twice in each truck he traded them in on trucks with allisons. 

problem with the ultrashift is brake applied clutch is disengaged. when you step on throttle the computer engages the clutch. 

if you are doing trailer work and do brake and throttle at the same time, the computer gets confused and tears the clutch out of the truck.

[mowerman]

sounds like they didnt think this one thru

[mechohaulic]

7 hours ago, fjh said:

Layers of it Joey! They had to implement this or the 10000 dollar clutch would burn up! As much as this trans works amazingly well when it screws up its pricey ! Provided all is working in harmony all is good! BUT if anything is out of tune get your wallet out ! I stopped by the shop last week the boys were doing an Mdrive clutch and front section re and re as it was to expensive for us to replace and input bearing they exchange the main box! Parts changing not mechanicing

 

Yep ! the New Age! If you stomp to hard to fast it will likely  derate on you 🙄! 

Thanks to all the replies .I was very hesitate about asking what's a grade gripper . always willing to learn new stuff .knew it was a "bad thing" when explanation said ;;new age idea. new age phrase came in during the '70's  and it meant bad news then and still today I guess. 

[67RModel]

2 hours ago, tjc transport said:

is the M drive like the eaton fuller ultrashift where it is a automatic clutch controlled by the computer?

Yes same. Computer controlled and clutch actuated with air pressure. Detroit DT12 is another one 

[fjh]

12 hours ago, mechohaulic said:

Thanks to all the replies .I was very hesitate about asking what's a grade gripper . always willing to learn new stuff .knew it was a "bad thing" when explanation said ;;new age idea. new age phrase came in during the '70's  and it meant bad news then and still today I guess. 

Yup mechanic is our pronoun  ! Not a technician! How ever there are a few here that qualify as Techs ! 🙄

[mowerman]

Joey, Mechohaulic and Jeff Weekes, are all  the best as far as High Tech the rest of us are just old and full of experience I guess we can include Mark T…. Rob used to be top-notch, but he doesn’t post anymore.

[brandone]

On 2/29/2024 at 12:02 PM, fjh said:

Yep ! the New Age! If you stomp to hard to fast it will likely derate on you 🙄! 

Can you elaborate on this?  We've been having some issues that I think this might explain.  Is this a "feature" of these trucks, or just speculation?  Thanks

[fjh]

 Bro !  likely  is the operative word there! Grade gripper  sticks You will likly get a clutch overload Code come up on the screen AND I  would like to think  the fuel will be dialed back momentarily  But I'm Not A guru on these I just Dabbled !