Broken Crankshaft Count?

Please pick the one that you had break


  • Total voters
    185

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,691
5,848
113
Phoenix Az
Has anyone else stopped checking this thread because they are tired of living their life in fear?

na i have a game plan already figured out if the time comes. its helps that i have not had one break on me personally but it gives me a chance to do upgrades inside ive wanted to do :D. kinda like when i put twins on and knew i would be building the engine at some point soon. 2 months later they shrank on me and off i went for the build.
 

NRA223

New member
May 20, 2015
288
0
0
I've had an intermittent low rpm vibration under load recently. Scares me but it is what it is.
 

NRA223

New member
May 20, 2015
288
0
0
Mine doesn't vibrate any more than it ever has at idle, and it runs great at WOT. It's mostly while lightly accelerating at low rpm.
 

TheDirty06

New member
Sep 28, 2014
115
0
0
Horton, KS
Add me to the list. My crank broke in my 06 LBZ. It was twinned but was on my stock tune and it just broke cruising down the highway under no load has 149k on the clock.

Now I'm gonna stop reading this thread because I'm in middle of a new build using a new lml crank and af cam and reading through this is making me wanna sell everything and abandon ship
 

MaxPF

JAFAWAM
Jan 12, 2011
182
0
16
Mesa, AZ
Looks like GM may of finally fixed the broken crank issue with the new L5P Duramax guys!!! Wonder if we will be able to use this crankshaft in builds with the excitor ring moved to the back

Short of using a more massive crank with wide radius fillets, rolled fillets are THE fix for fatigue cracking at the crank journal. This technology has been proven for decades on nodular cranks. I don't know why it took GM 16 years to implement it on the DMax. Given the gasser-crank dimensions of the DMax crank it should have had rolled fillets from day 1.
 

WolfLMM

Making Chips
Nov 21, 2006
4,005
26
48
38
AL
Well I know LML cranks are prone to breaking just like the others, but I feel like I made the right decision putting a brand new lml crank in my lmm build. I wouldn't be able to sleep knowing I had a 150k lmm time bomb in my brand new motor.
 

Fingers

Village Idiot
Vendor/Sponsor
Apr 1, 2008
1,717
96
48
White Oak, PA
Short of using a more massive crank with wide radius fillets, rolled fillets are THE fix for fatigue cracking at the crank journal. This technology has been proven for decades on nodular cranks. I don't know why it took GM 16 years to implement it on the DMax. Given the gasser-crank dimensions of the DMax crank it should have had rolled fillets from day 1.

THE improvement is the enlarged rod journals. That increases the rod/main journal overlap greatly increasing the cross section. The throws are just too thin and do not provide adequate resistance to twist.

Everything else is icing on the cake.
 

GunnDura

New member
Jan 8, 2017
22
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59
It appears, according to the poll in the OP that the LML has been perhaps less prone to breaking? Was there an upgrade to the crankshaft by GM in the LML?
 

coker6365

Coker6303's ***** Daddy
Dec 4, 2011
486
16
18
It appears, according to the poll in the OP that the LML has been perhaps less prone to breaking? Was there an upgrade to the crankshaft by GM in the LML?

More than likely that has to do with the years of service and probably less modded lml's running around. Time will tell. I bet the data source is a tad misleading in that manner vs. having a set number of variables.
 

GunnDura

New member
Jan 8, 2017
22
0
0
59
More than likely that has to do with the years of service and probably less modded lml's running around. Time will tell. I bet the data source is a tad misleading in that manner vs. having a set number of variables.


Gotcha. Makes sense. :thumb: