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Is this normal??

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837 views 5 replies 5 participants last post by  mgray1982  
M
#1 ·
Usually noticed when going downhill at speed (but happens any time vehicle speed is over 50kph), when the brake is applied, RPM`s drop to about 600rpm, take the foot off the brake and RPM`s go back up to about 1000. It worries me because oil pressure goes down with the RPM`s.

I also notice that when I take my foot off the gas, the transmission disengages and the vehicle runs free. Only when RPMs get high enough to match the current speed does it engage again. Maybe this is normal for diesels?? But usually the transmission stays connected the whole time with every other gasser I`ve driven.

Normal?
 
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#2 ·
You just described the working of the TCC... torque converter clutch lockup. Brake tap unlocks it (like pressing the clutch on a stick shift). Once you reapply power (within reason) it will lock in again. RPM change is normal. In fact, you may hear the engine almost go totally mute in decelleration... or at least bus 1 used to do this.
 
#3 ·
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#5 ·
yerp thats normal
 
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M
#6 ·
Right on, thats what I thought but just wanted to make sure. I am definately paranoid right now as I want to make sure I make it back to my own country before anything serious happens

thanks again
 
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