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View Full Version : LMM 2007.5 2500hd broken exhaust bolts question.



ff43sc
12-13-2011, 16:43
I have a 2007.5 LMM duramax 2500hd LB with approx 55000 miles. Driving from work yesterday heard a clanking sound, pulled over to find that all three bolts that hold the Muffler/tailpipe triangular flange to triangular flange behind what i believe is either cat or DPF had broken off flush.
All 3 bolts/studs are still in place in rear flange, and didn't come out easy.
Any idea why all 3 bolts would have failed, has any else had this problem. Could the DPF regeneration cause enough heat to weaken and cause these bolts to break. And is this something that should be under the 100k power train warranty. The exhaust system is still in very good condition.

DmaxMaverick
12-13-2011, 22:43
I don't know why your bolts would break, and haven't heard of it anywhere else. Could be caused by any number of reasons.

The repair should be covered by the powertrain or emission system warranty.

Kennedy
12-14-2011, 14:09
The DPF runs so cotton pickin hot that there is a lot of corrosion and the flanges basically "heave" until the bolts pop.