Turning flywheel specs

Do you already have the tranny pulled? You can get a good electronic micrometer for 20$, and any machine shop will have professional micrometers.
Call a different freightliner dealer, they should have access to the exact part number based on your Vin. Parts may not know, but I guarantee the shop foreman will. Ask the dealers who they outsource flywheels to, and call the vendor directly.
Most dealerships farm out a lot of work these days, it's faster and cheaper than retaining an in-house setup.

 

With the flywheel on the engine, use a straight edge across the flywheel housing (where the trans bolts). Pry the crank back so the thrust clearance is toward the rear. Use a mic or dial caliper to measure the distance from the friction surface to the transmission mounting surface. A new flywheel is 2.5". Measure from outside the contact area to get an unworn measurement. If it's 2.5", then it's never been turned. If it's more, then it has been turned.

You have the lightweight flywheel, and I don't know the specs, so if you're confident in your .508mm spec go from there, but it will still be 2.5" new and you can tell if it's been turned. .508 mm seems wrong to me, most flywheels have more wear than that and I can't see needing a new flywheel every clutch job. For a standard flywheel, you can turn them quite a few times, the replacement spec is 2.73". Those #'s are not a mistake, you can literally take almost a 1/4" off of a standard HD flywheel before it needs to be replaced, so that .508mm spec seems unlikely to me, even for a lightweight flywheel.

Where did you get that $2000 price? I found that part # on google for under $500.

Also use that measurement to determine if you should use a clutch brake spacer or thicker clutch brake. Once you turn a flywheel, if you need to adjust the linkage too much to get the clutch brake right, you'll end up adjusting the clutch to get the free play and wasting clutch adjustment, which shortens it's wear life. Cutting the flywheel moves the clutch closer to the engine, it's best to match that with a clutch brake spacer, not use up clutch adjustment.

 

Personally, the deepest I have ever seen on a flywheel was 2.6" ish, meaning a total of .100" or so was taken off and this was an older truck. I've been doing this for almost 30 years and have never replaced a flywheel for being cut too much. I've changed them for other reasons, but not that. The splicer book says 2.73"

Here's copy from the book for future reference:

 

I have only seen one flywheel cut too much. was a old cat with close to 2 mil miles. the clutch hub hit the head of flywheel bolts. thats about the only time one didnt work. but dealerships and cat didnt know specs either.

 

Hard to say, but maybe a linkage issue? Is it really bottomed out? It's possible that it's just stuck? I've had them that would not move and had to remove the adjuster and shake it with an air hammer to free them up. This really isn't uncommon with good drivers that float gears. The longer you go between clutch adjustments, the better chance it has of seizing. I've seen a lot of linkages adjusted wrong, I've even see people adjust linkages to get more clutch free play. On a new clutch, I set up the linkage for correct clutch brake operation. Then if the correct clutch brake (or spacer) was used, you have very little adjustment to get the right free play. Or is could simply have been a clutch that wasn't built right to being with. Spicer is pretty good with quality control, but I'm sure some out of spec clutches slip through occasionally.

 

Hello I have a similar question I just replaced clutch on a 1994 Peterbilt 377 it's a glider motor is 1992 Detroit 60 12.7 9 speed transmission no I have a vibration like a shudder between 800 and 1000 rpm also at 1400 rpm does not matter in neutral or in gear I did get the flywheel cut and used a rebuilt mid America clutch what do you think is the problem flywheel cut wrong or clutch thanks