DMF failure symptoms?

[fiverpuller]

How does one know when the old dual mass flywheel is ready to fly off? At idle something down near the tranny makes a scary rattling/chattering vibration that shakes the truck. If I push the clutch in it goes away. If I bump the rpm over 1200 it goes away. I am totally lost here. Just had the flywheel out during engine swap but the friction disc looked ok so I wasn't ready for the Lucky Mod. There was some rotational play between the two halves but I didn't measure it. Also this flywheel is on a 6.9...could it be out of balance? I have so many issues with the Limo I just want to push it off a cliff. Only got to drive it 20 miles so far!

 

[towcat]

how do the dampner springs look like? you can tell if they are ready to pop out of the sheet metal housings and if the plastic dampner is shot.

 

[fiverpuller]

I only did a brief inspection and nothing looked broken or ready to fail. How much play can these have? Or is any play too much? If it's just regular DMF noise then I can live with it for now.

 

[towcat]

If memory serves me right, it should be 1/2 to 5/8 inch lock to lock. Do a search on the used flywheel Dozer was haggling over. I was more sober then than I am tonite.

 

[Agnem]

Sorry to hear you didn't do the Lucky Mod while you were in there. It seems DMF failure occurs often right after a clutch change out. The Ford dealer we bought our 93 from had just replaced the clutch about 1000 miles before our DMF started to go. When I did the lucky mod, the clutch parts looked like they had just come out of the box. When you shut the truck off, is the last sound you hear a kind of tinkling or sqeak? If so, I'd say your DMF is going. It will run for quite a few miles yet, but the noise will get so bad you'll be embarrassed to drive it. There is also the possibility of the bell housing cracking if it gets bad enough. I know this isn't good news for you, but look at it this way, it won't cost you anything but time to mod it.

 

[fiverpuller]

I will need to buy the friction disc with the springs though. Is the Luk disc that best way to go. Something like $175? A new clutch is easy...only a few hours work. I just want to drive this thing already.

BTW...I think the engine miss is what wakes up the DMF noise.

ON EDIT: There was a pretty good clunking sound coming from down there when I shut it off.

 

[geonc]

When the DMFW in my old IDI was going it siunded like a washing machine that is out of balance on the spin cycle

When the DMFW went on my '96 it flet like the u-joints were disentegrating----BAD vibration---so bad that I immediatly pulled to side of the interstate and started grabbing the drive shafts---all were fine

So I limped home only to have the vibration worsen....got home and dropped the clutch cover and tried the pry bar trick....do you think it was a problem when I was moving the TRANS case

It almost caused me to cancel my IDI labor day gathering last year

I post the pics as often as possible to show the damage caused by neglecting the warning signs

There is a total of 42 inches of tig weld

Take care of that ASAP!

 

[fiverpuller]

Nice pictures. I do plan on the Lucky mod in the near future. I think this noise is minor compared to what you describe. And it goes away above 1200rpm with no vibrations. Don't get me wrong...the mod IS on my list of things to do. Here is what I got off the ZF link:

Condition: (Noise While Stopped — Transmission in Neutral)
Noise disappears when engine RPM exceeds 1500 without depressing clutch pedal.
Possible cause:
Neutral rollover is caused by the engine firing pulses transmitted through the gear set.
Action:
Check engine idle quality and speed. A rough or low idle will aggravate this concern.

My truck idles extremely rough right now and if the noise/vibration goes away after a "tune up" I will drive it for a bit. Like I said...I WILL do the lucky mod in the future...or now if noise doesn't go away. I just need to get the parts still...mainly ZF friction disc with springs. That and the stupid turbo piping has to be removed to pull the tranny.

 

[fiverpuller]

Got the spare IP in and she purrs now. :draw I blew the 30amp glow plug fuse and it still fires up in a few seconds cold. What's with the huge fuse anyway? My point of this reply is the flywheel noise went away. That's not to say the DMF is not a potential problem...it just doesn't scare me anymore. So maybe tomorrow I will get to drive it around a bit for a better feel. In the meantime who sells the springed friction disc? Just Luk?

 

[Dsl_Dog_Treat]

In a good way but a bad way also the DMF does tell ya if you are have in some engine/fuel issues as the motor at an idle if not running smoothly will transfer that unevenness thru to the DMF rattle. On the other hand leaving it running like that over time does take out the DMF as weird as they are.

As for the Friction disc kit. I got one thru Pep Boys and was around $200.00 as a replacement kit. Had clutch, P/P TOB and pilot bearing. Was just what was needed for the Lucky Mod as well if in yer future.

Ron