That would be machanical failure and should be covered under warranty, unless he was hauling over gcwr or has a box on his truck!

I've seen several with the center busted out.

 

i think i get what you guys are saying about letting the clutch out before gas but you drive a gas vehicle the same way dont ya???? its called NOT RIDING THE CLUTCH!
wether gas or diesel just drive right!
you have to give a clutch some gas to keep it goin....thats a fact.
if your pulling a 30ft trailer down the highway and you go to slip into 5th and dont give it gas untill your foot is off the clutch.......whatch ya truck drop rpm's and learch forwared....NOT how you drive a clutch.

 

Not trying to start an internet peeing contest, but if you have ever driven a semi, it kind of changes your way of thinking toward shifting your truck. I rarely use my clutch for shifting, only when stopping and starting, I shift on the float 90% of the time. The 6 speed is good for this. If its real cold outside and the oil is cold in the tranny it doesnt always work so you do wind up shifting with the clutch for a bit till the oil warms.
With 4.10s, I leave stoplights in second, let off the clutch steady and quickly without any throttle application, then go thru my normal shifting schedule. Maybe I'm doing it right, maybe I'm doing it wrong, maybe I'm practicing for my Sout Bend Con FE, I don't know, but it seems to work for me.

 

I've only been over 10,000 lbs once for 10 miles, and I've only towed a 3,000 lb trailer a dozen times for 20 miles or so and twice for 400 miles. The rest of the the time I'm empty. I only touch the throttle enough during take off to even out the little lurch you get if you don't. Even if that was too much, I don't think it wears out a clutch at 65,000. That's way less wear than if I were regularly operating near max GW regardless of clutch technique.

Of course, now I cannot compare back to what I had, but there are little lurches that are gone that in retrospect must have been the clutch slipping.

Overall, it is just completely DIFFERENT than it has ever been. More like other trucks that I've had that have all gone 150K plus on their clutches.

Tad

 

Another thing...need12v's comments about shifting without a clutch I can relate to. My dad used to run a portable building business back in the 80s. I drove plenty of big trucks in the Ford 700 class (way big since I was only 130lbs back then!) and learned that they shifted much better without the clutch. I was very surprised when I first got this truck that it simply wouldn't do that. Sounds like I need to see if that is different too.

Tad

 

The difference is that the "big trucks" you drove had non-synchronized transmissions. The NV5600 is synchronized and not designed to be shifted without the clutch.

Rusty

 

is it even possible to slip out and into another gear without the clutch when driving the 6-speed in our trucks????

i know ya can do that in a semi, and i know people who drive semi's but they dont jump in a pick-up and start to drive it like a semi...like Rusty said its a NON-SYNC tranny....thats NOT the same thing.

and to say using the clutch on these trannys is more damaging than just...what i would say....forcing it into the next gear...i dont think so.....

everyone drives diferent...not that there are not "rights" and "wrongs" of "how to's" but using your clutch is NOT wrong. and to say that because a man lost his clutch at 65K was driving wrong cant be said unless you have driven with him...right??

 

Tad, goodluck with your new clutch. If I was you I wouldn't try to perfect shifting without the clutch like in a non syncro tranny. In our trucks it can be done but if you mess it up it can be costly in the long run.

Bummer this thread turned out to be a edit match by someone who seems to know everything...even knows his truck has an Allison six speed manual vs. the NV 5600 our trucks have

 

 

I think if it was defective then you have your answer . I just replaced my stocker at 100K and it looked almost new, even after a few power pulls and it slipped. I installed a SBC con ofe and peddel pressure was nothing. but it is starting to firm up again.

 

It most definitely will not shift without a clutch. No big deal now that it shifts so much nicer. This truck is fun to drive again!

 

Now that you have a new clutch maybe try starting in 1st gear instead?

 

Doh! A friend of mine pointed out the obvious connection... It make sense that the leaking rear main seal would cause oil to get onto the clutch, causing problems. Sure enough, the old clutch plate does smell slightly of oil. Mystery solved.

 

Talking about starting in first vs. second gear, my truck around town unloaded rarely sees 1st, 3rd or 5th, mind you I have 4.11's.

 

My original clutch had right at 160,000 on it when i changed it. I pull heavy loads almost everyday( dozer or backhoe). Loaded i start out in first, empty i use second, i have done it since the truck was brand new. My second clutch has almost a 100,000 on it. My truck has 4.10s in it and i do not touch the throttle until the clutch is fully engaged in any gear. Dave