Dual mass flywheel paranoia ?

[RLDSL]

I need to know if there's really something gong wrong here or if I'm just suffering from dual mass flywheel paranoia. I just put the rebuild engine in a couple of weeks ago and checked the flywheel, no excess play, about 3/4 inch movement, no broken springs, no signs of wear in the springs, truck has about 225k on it, but the flywheel is obviously not original, doesn't look that old , very little surface wear ( I've had this thing about three years now but not many miles in that time)

the thing occasionally makes the kinds of rattly noises at idle in neutral everyone speaks of , won't make any noise in gear with the clutch in.
Doesn't make any noises when shutting down.
If I bring the rpms up a hair it goes away.

Is it most likely just the idle speed just set a bit too low and I'm worrying about nothing? I know using a dash tach to try to set idle speed isn't the most accurate thing on earth

Thanks-------Robert

 

[Double-S-Diesel]

3/4" is excessive play, that is the reason for the rattle.

 

[RLDSL]

I thought 3/4 was getting right near the limit?
What doesn't make any sense is that the thing wasn't making a peep before I pulled the engine out, It all started with the fresh engine installation which is what has me scratching my head and thinking it might be related to something else.

 

[Classicfordguy]

Could be after the rebuild your idle is set just a bit different causing the problem. My daul mass had almost an inch of play before I chucked it, went with a solid with springs in the disc when I did my rebuild and it even makes the smallest rattle at idle but goes away as soon as I depress the clutch.

-Rob

 

[towcat]

DMF issues 101....
the DMF issues is the "effect" of of a "cause" elsewhere. A cylinder imbalance or injection pump or injector issues will cause a DMF to go into rattle mode.
This has been proven at the stealerships to the point where techs must get a second verification before condemning a DMF for warranty reasons. check all the other items in the motor first.....BUT... if you have inspected your DMF and have found the springs threatening to outgrow their caged area, replace the DMF immediately. At best the DMF will shatter or at worst it will take out your bellhousing on your ZF5.
1/2"play is new. 5/8" is service acceptable. 3/4" is at the replace mark.
your truck...your wallet...your call

 

[6 Nebraska IDIs]

we put a brand new Valeo direct DMF and clutch kit into my moms green 94 CC, and the damn thing would still rattle, and we stopped driving it, condemned the engine and said screw it. We bought a new 6.9 that we're going to drop in. There's a cyl running low compression or something causing it to have a slight miss, or stumble and its just beating the crap out of the new DMF. We said at $3000 the DMF was worth more than the engine.

 

[Dsl_Dog_Treat]

3/4" is at the limit but if the springs as said aren't looking to jump out.
I do believe that if you have the injectors pop tested, you are gonna find one or more that are letting off before they should be.

 

[RLDSL]

Has anyone got pictures of what the spring area would look like healthy or worn?
I looked the thing over carefully and there was no signs of any kind of wear around the spring area . the springs themselves or the sections that retain them all looked great.

I do have two injectors that are leaking at the fittings and driving me nuts, # 1 and #3 at a pretty stout rate. I loosened and retightened them yesterday but haven't had a chance to see if it's made any difference yet. Only drove it a little and it didn't make the noise but I was shuffling a trailer around.

 

[towcat]

does the springs have any shiny marks on the coils? Also, the plastic buffer at the ends have a "half moon" cut into the metal, when it wears out, the half moon starts getting oblonged out. believe me, if the springs are starting to think of a leave of absence, it's pretty obvious.
your leaking injectors is the core of your problem. reduced pop pressure is the start of the chain of problems.

 

[RLDSL]

does the springs have any shiny marks on the coils? Also, the plastic buffer at the ends have a "half moon" cut into the metal, when it wears out, the half moon starts getting oblonged out. believe me, if the springs are starting to think of a leave of absence, it's pretty obvious.
your leaking injectors is the core of your problem. reduced pop pressure is the start of the chain of problems.

I don't recall seeing any of those things on it. I just punched up a picture on the parts america site and it looked like the one on there, plus grime.

I went out and fired the thing up and let it idle a while, It's quieted down a bit . #3 has stopped leaking after fooling with the fittings, but #1 is still leaking.

If I've got a real potential for problems here I might as well tear into it I've got a long trip planned in a couple of months, I just don't want to be jumping the gun. Just kind of gets me.. if the thing had looked bad I would have junked it a couple of weeks ago before stuffing the engine in.

 

[RLDSL]

Update:
I finally got all the injector leaks stopped thank goodness at these fuel prices ) and lo and behold, no more flywheel rattles.
Sounds just as good as it used to. doesn't make a peep now

 

[Devilish]

I think I'll have the injectors tested on both of my trucks

 

[Agnem]

Lucky mod!