Clutch Problem

[rthomas]

My 2003 3500 DRW with NV5600 seems to have a clutch problem. Its not slipping but requires pedal to the floor to disengage and then after shifting will engage with only small release of the pedal. I don't remember it being this way. The truck is used very seldom now and only has 80,000 miles over 16 years of service. No drive train modifications or repairs have been made to the truck. Only the fuel lift pump has been replaced and a BD exhaust brake added. So there is a lot of clutch action on down hills when hauling a loaded horse trailer.

The clutch actuation is all hydraulic with no adjustment. Is there a way to inspect the clutch hydraulics for low fluid, leaking master/slave cylinders, etc? Is there a way to inspect the clutch facing without tearing everything apart?

 

[Prairie Dog]

When that happened to me, the hydraulics were shot. I had a VERY short warning period before it totally gave out.
I'll probably be flamed for this but I would stick with the stock hyd system.
I tried the so-called "heavy duty" aftermarket hyds and hated it. Not only are the parts (cyl) the exact same size as factory (so not really HD), they're all metal and transmit vibration from the trans to the pedal. I ended up tearing the "HD" system out and going back to stock.
BTW, the new factory hyd's are updated to isolate even more of the NVH from the trans than your original hydraulics did.
Oh and contrary to what they'd like you to believe, the factory hyd's work fine with a SBC.

Scott

 

[GCroyle]

The hydro's can be tested.

Unbolt slave cylinder, remove push rod and dust boot.
Attach steering wheel puller loosely on flange, turn puller screw out a bit until it contacts and centers on piston, now finger tighten nuts.
In cab push on clutch pedal with your FINGERS ONLY until you feel pressure being created.
Did you read FINGERS ONLY in above line?

Assessment criteria:
Distance clutch master cylinder push rod travels. Measure it.

1/8" or less, good news for the hydro's.
1/8" or more, good news for you. Travel greater than 1/8" indicates you compressed AIR first and then DOT3.

This is your only external hope. Air in hydro's. Or MC push rod pin is half way worn thru, or thick floor mat has slid under pedal and blocking full travel.

And what Scott points out is very likely, the newest factory hydro's may have added doohickey's to act as a filter to make pedal less able to transmit pulses back to your foot.

Gary

 

[sdeeter19555]

Had an OFe do the same thing, it was a warped pressure plate...

 

[KATOOM]

My 2003 3500 DRW with NV5600 seems to have a clutch problem. Its not slipping but requires pedal to the floor to disengage and then after shifting will engage with only small release of the pedal. I don't remember it being this way. The truck is used very seldom now and only has 80,000 miles over 16 years of service. No drive train modifications or repairs have been made to the truck. Only the fuel lift pump has been replaced and a BD exhaust brake added. So there is a lot of clutch action on down hills when hauling a loaded horse trailer.

The clutch actuation is all hydraulic with no adjustment. Is there a way to inspect the clutch hydraulics for low fluid, leaking master/slave cylinders, etc? Is there a way to inspect the clutch facing without tearing everything apart?

The initial "disengagement" you describe is neutral into gear, right? And then it takes less pedal distance to shift from one gear to the another, right?
Typically thats because of hydraulics but it can also be because of a dragging pilot bearing or a problem with the pressure plate and/or disc.
You can tell if the hydro's are bleeding down by parking on a flat smooth surface. Then press in the clutch, shifting into gear, and holding the clutch pedal depressed while idling. If the truck eventually starts to act like it wants to roll then thats the hydro's bleeding off pressure and allowing the clutch to slowly engage. Generally this test is done in less than a minute.

If the pilot bearing is bad then its very difficult to get into gear from a stop and you'll feel it struggling to engage into another gear. Its IMPORTANT to never force the shifter into gear either otherwise you place immense amount of stress and wear on the synchros.

As for hydraulics, I like the ones Southbend has. Much better than anything you'll find at the part store.