What makes a clutch brake go bad?

My clutch brake is definitely gone, because I can shift just fine but from a dead stop I can't get the input shaft to stop spinning.

*grind**grind**grind* I Is aRe Truk DriVeRt!

I wish there was some sort of indent on the clutch stroke though, so I could feel the clutch brake engage. I've got big feet and long legs, I'm sure I've pounded that clutch to the floor at times when I shouldn't have.

 

I don't shift by the Eaton book, either, 95% of my shifts are clutchless. That being said, I posted those videos to show that Taildragon was not inherently wrong, that Eaton, the manufacturer itself, has said that you can use the clutch brake if needed for a quick up-shift. By the same token, it also advised using the clutch-brake to get the truck into gear when stopped if equipped with one. Thus, both Taildragon and Real Deal/ Pedigreed Bulldog were in-fact, partially correct.

In all honesty, I was unsure of what Taildragon had said at first because I had never heard of using a clutch brake like that. But, seeing as he (if we trust the internet) has nearly 40 years of driving, I saw it fit to give him the benefit of the doubt. I knew about those videos and decided to see if that was covered anywhere in the video. It turns out it was.

To re-state, more accurately, what a certain individual in this thread said early, you can't trust everything you read on the internet. BUT, you can do your best to verify what you read with a little research.

 

I would like to Thank You once again ColoradoGreen for these excellant posts, not only for the purpose of this thread, but in addition, to the memories that came back after a few minutes of watching the videos. I drove for an outfit that had a mandatory meeting every quarter, any drivers that were in were required to be there, as well as all of the shop personel and shop management, and we were paid for the time, I have watched these videos many times and had forgotten them. I would like to point out one thing in the first video when the narrator starts talking about the clutch brake, he uses the proper clutch brake name, "The Upshift Clutch Brake", now why do you suppose they would give that particular name to this new addition that they had started installing in the clutch housing? I have one other question about this matter, and then I am going to put it behind me, and that is, "how do you think that we got these things in gear before they started putting the clutch brakes on", it was the same clutches, the same transmissions, the same engines. I don't ever remember having a problem like that, if I did, it was a fifteen minute clutch adjustment and you were on your way.

You have heard the old saying "put your money where your mouth is", well ColoradoGreen, this is why I Thank You and appreciate your time and effort, you put your time and effort where my mouth was, I was not able to find what I thought would be easy in this electronic age, and I would have appeared to be "one who occupies the room of a fool", but you put your time and effort in to something that you could have easily walked away from, My Hat is off to you ColoradoGreen, Thank You.

 

The video reffers to it as an "Up-Shift Clutch Brake" which I am wondering if that was an old style of transmission and someting inside it??? As current clutch breaks do not operate in that fashion at all.

Also, even as the video stated, you should never use the clutch brake when you are stopping or down shifting.

This is why most clutch breaks fail, as drivers will come down an exit ramp at 60-70mph and just push the clutch to the floor to coast to the stop. This is applying the clutch break at say 1500rpm against a stop, which usually either shears off the tabs or causes it to just burn up and sometimes, just crack or explode.... I've replaced many of these,

 

That is a synchronized tranny
A clutch brake does nothing more the stop the free spinning gears put in motion at idle to allow putting into gear from a standstill.

 

I’ve never heard of it being used for anything other than to put the transmission in gear at a dead stop without grinding it, and to not push the pedal all the way down with the truck moving.

That being said I’m a fan of using the clutch while executing any shift, down or up. I don’t necessarily clutch it out of gear, but I always dip the clutch before sliding it back into a hole. If you bobble a shift you can sometimes catch it before it shocks the driveline.

 

The only synchro is in the back section that is for high low range selection. No other synchro is in a twin or triple countershaft box in NA

 

What your talking about I know not.
This page is ridiculous.
For its own integrity this whole thread needs to be deleted.

Coloradogreen
Go on an toss yours out then.
If you've any clue where it's at you will know it's a pretty simple process.
Get back to us after your first ride around the lot without it.

 

This is an old thread.......but.


At one time Volvo installed self-adjusting clutches. Clutch operated the same
when driving the truck......but it would adjust itself. When the clutch was wore
out, couldn't adjust any further, the clutch brake would eventually be out of
adjustment as well. Time for a new clutch............or ignore the grinding for weeks
till the transmission needs rebuilt as well............company I drove for did that. Didn't
want to fix the clutch so they let it go till they also had to fix the transmission.

 

Eaton also called the clutch brake the “upshift brake”.
When the first Rt/Rto9513’s came out it was recommended by Fuller to be used to aid in quicker upshifts in situations were the truck can slow down in an upshift like hill climbing. It was mentioned in the manuals.