Folks I have a problem with my truck and could really use some help. Truck is

2002 CTD 6-speed HO
Current LUK ceramic clutch
150K miles

At about 120K miles I found that I started getting a slip-grab behavior when feeding out the clutch. At that time I assumed that the clutch was going. I had it replaced with a LUK ceramic and found that absolutely nothing changed with regard to this. Specifically as I pull away from a stop as smoothly as possible everything feels OK then BANG, the system catches. There is no level of smooth on the clutch that can eliminate this. I have checked the u joints out but they are fine (replaced anyway) and the rest of the suspension seems OK. I took the truck to a clutch shop and they said that I was getting suspension wind up (think drag racers without torsion bars) and this unwinding was what I was feeling. I don't buy this at all as the unwind is a hard catch. Right now the truck is drivable by me but nobody else really. I am wondering about the rear end (DC stock limited slip) but still suspect the clutch system somehow.


help and thanks for any advice folks can offer.

 

IF the driveshaft is ok (check the slip joint on the split shaft) then its time to pull the differential cover. You don't mention having a 4x4, so the slippage isn't in there.

If you don't have any problems in the diff, your trans needs a teardown and inspection.

 

my guess would be that your fly-wheel is "burnt" and it is hitting that spot, speeding up and then hitting the good part and then "locking" up like it should (resurfaceing the fly-wheel should fix the problem....the shop i worked in always sent them out and had them resurfaced when we did a clutch)....i have also seen ring gears that are missing a few teath, and the pinion is missing about half its teath....but that would cause it to slam all the time. so if i had to point my gun, close my eyes and shoot.....i would say burnt fly-wheel.

 

Should have included a couple things I think. My truck is a 4X4 and when the new clutch was put in the vendor said that they turned the flywheel. I can't confirm or deny this. I get the exact same slip catch in 4WD as in 2WD as well as loaded v. unloaded.

thanks for the inputs so far, I will have the slip joint and rear dif inspected. I'm due (actually over due) for new fluids in the dif/tranny/transfer case anyway.

thanks all.

 

You may want to look inside the clutch slave cylinder. The bore may have a groove in it that is causing the piston to hang up on and not allow the full release for the clutch until you hit a bump or the stress from the engine or tranny cause it to release and Bang clutch engages.
Just my .02