2nd Time... in 5k miles 2001 GMC with Flywheel Issues

[Howlan]

I looking for some info as I just purchased a used 2001 GMC Duramax Oct 31st that now has 37,500 miles on it and I apear to having some major problems. On the way home from work last Thursday it started making a really bad knocking sound when I would slow to stop or be idling. I went straight to my GM dealer (also where I bought the truck in Oct) to get them to check. They are saying that it has something to do with the flywheel, and that it is a major problem. They also said that the truck is out of warrenty now (I've put over 2k miles on since I bought it from them and it has over 36k too). They said they would try and help me, but couldn't promise anything. It will be up to what the Service Mgr can get taken care of if anything. He will not be back from vacation until tomorrow.

Anything that stands out that this problem might be, or that might help me with my issue. I'm really worried I getting ready to get raked over the coals. I really like this truck and want to get back on the road soon.

Thanks for any help!!

Howlan in Wilson, NC

[ 04-18-2005, 05:51 AM: Message edited by: Howlan ]

[More Power]

Click HERE (http://www.thedieselpage.com/duramax/ZFS-650.htm) to see an article on the ZF trans, which also mentions the flywheel upgrade.

MP

[Howlan]

Thanks More Power, The transmission in my truck is automatic, not sure if that changes anything.

Thanks again, Howlan

[More Power]

To my knowledge people aren't having ongoing problems with the Dmax/Allison flexplate/FW. These are heavy-duty units (combination of cast iron and steel). There are no moving parts - bolts to the engine using eight large fasteners and to the Allison torque converter using six bolts.

http://www.thedieselpage.com/images/dmaxflexplate.jpg

In the early days of the Duramax introduction there were a few trucks that made it to dealer lots with improperly installed TC bolts (either no thread locking compound or left loose). The bolts eventually worked loose, and caused a knocking sound near idle. All new bolts come with locking compound pre-applied.

MP

[precision37]

Should be covered under the 100,000 mile powertrain waranty.

[MaxACL]

Look in your warranty booklet (Page 12 I think) wnder specific items that ARE covered (small print) and you'll see "Flywheel".

I found out the hard way after I paid AAMCO $1200 for my flywheel replacement. (ZF6)

Mike

[Howlan]

Thanks for all the info! smile.gif

[Howlan]

Hard to believe this, but I got my truck back in January repaired with a new Flywheel. Well after about 5,000 miles she had to go back in with the same problem at the end of March. Flywheel/FP replaced again, under warenty again. My truck has a pretty easy life as most of the miles are highway without towing. I pull a camper (8,000lbs) every once and a while. Any thoughts about why this happened again? I can't understand why this is a continued problem, and I'm worried it is just going to happen again.

[Kennedy]

So was it knocking again? There were some issues with loose torque converter bolts on 2001 models particularly. Red loctite on the bolts should cure them loosening in the future.

Knowing what actually failed on this truck would be very helpful.

GM "good faith" or "good will" warranty should cover this...

[Howlan]

Yes, she began knocking again. They have repaired it again and it was covered. Just a hassle, and no truck for a week or two each time. Hope it doesn't come back again, kinda worried it will. Not sure if they loctited, but hope they did!

[madmatt]

every time the flywheel is removed, the bolts are to be replaced. Are they replacing them and torquing them correctly? I'd suspect they skipped a step somewhere.