I am in the process of upgrading my license from HC (heavy combination, trucks up to 42.5 tonnes) to a MC (multi combination, any truck). Haven't driven a crash box for a number of years so thought it would be a good idea to do a couple of lessons to refresh my skills. One of the trucks I drove was a Kenworth T604 (cousin to the T600) but the clutch was a bit weird, insofar that there was virtually no free play and I had to basically take my foot off the clutch every time, which given the clutch height was a real pain. The actual truck and clutch can be seen here http://www.youtube.com/watch?v=MvEarMEs_Ho&feature=related I don't think that is normal but I may be wrong. All the other truck clutches I have come across have always had at least an inch of free play before starting to disengage the clutch. That way you did not have to take your foot off the clutch and was much more comfortable.
Actually thinking about it, is it possible to have the clutch height custom set to your preference? I am 185cm (6foot 2) and have fairly long legs, guess someone who has short legs would be comfortable with that clutch. I just about had my knee touching the steering wheel, which I had up as high as it would go.
If the clutch pedal has no free play, real easy to smoke the clutch.
You're going to have to adjust that....Like Willie said if there is no free play you are going to smoke that clutch.... if you get under the truck and look up at the bottom of the bellhousing for the tranny there should be a window where you can see the clutch.... on the back of the clutch pack there should be an adjustment bolt that you can turn with a wrench either left or right to get the freepaly you need. If there is no adjustment there then you might hae to go through the linkage and loosen it up that way but I'm 99 percent sure there is adjustment on the clutch pack itself
The clutch just needs to be adjusted. You need to make the bottom adjustment through the inspection hole first to obtain a 1/2" gap between the throw out bearing and clutch brake. After that adjustment is made and the 1/2" gap is correct then check your pedal free travel and you should have 1 1/2" to 2". Ordinarily the bottom adjustment returns the pedal free travel and nothing more needs to be done, but if not then the linkage can be adjusted to obtain the correct pedal free travel.
yeah what he said....there are two types of adjusters also ..one is a 5/8 nut that you push in and turn clock wise to get more free travel and on the other type you gotta remove a stopper and pry the teeth clock wise to get more travel...they make a tool for it but i use prybar and screwdriver etc. and you gotta have pedal pressed when doing this. and it takes a 1/2" socket to remove inspection cover btw.
Cheers for the replies, good to know I am not going crazy. Given that adjusting the clutch is a straight forward job and someone who knows how to do and has the tools, eg a Kenworth dealer, can do the job in 10 minutes, why would they risk damaging an expensive clutch? My theory is that the clutch has been adjusted as far as it can go and they are trying to get the maximum out of it. Spose given my luck the clutch will go when I have to demonstrate a hill start pulling a B double.
Found some vids online that show the procedure quite well http://www.youtube.com/watch?v=6-rxRm_9uZw&feature=relmfu http://www.youtube.com/watch?v=LoTTOisaKVg&feature=relmfu http://www.youtube.com/watch?v=HKkHVQHuVIw&feature=relmfu and the official pdf from eaton http://www.roadranger.com/ecm/group...roadranger/documents/content/rr_clsm-0200.pdf
Those videos pretty much describe the procedure Hendrik, I've been doing it that way for years. I only differ in one respect, when I climb in the cab, I'm don't first look at pedal free play, I first check if clutch brake is adjusted proper if it's a heavy duty clutch. Many medium duty clutches don't have a clutch brake, but a truck that would drag B doubles you describe most likely has a clutch brake, so the first thing I do is (if necessary) adjust linkage for clutch brake to work proper. Once that's done, adjust the clutch ring for proper free play. And if you're working with a cast pressure plate that requires adjusting tool like shown in video, that tool is available from OTC tools.
Guess either way way will work, Eaton say to check the bearing to transmission brake first and then check the squeeze on the tranny brake, lastly adjust the free play. The tranny brake works pretty well in the truck and it is a heavy duty one, judging by how hard it is to push down, especially after being used to a air assist clutch. Yeah if you are doing this job every know and then it would pay to get the proper tool rather than mucking around with pry bars and big screwdrivers.
There is a method for my madness Hendrik. In most cases, the clutch brake adjustment is fine. However, I have ran across a number of clutches that someone didn't adjust properly (linkage) and the clutch brake is now out of adjustment. The only way to adjust the clutch brake (where pedal squeezes brake) is by adjusting the clutch linkage. If you were to adjust the clutch first, then afterwards find out the clutch brake is not adjusted proper, well, you're gonna have to do the clutch adjustment a second time after you adjust the clutch brake proper.