Duramax cracked flex plate knock

The bd flexplate is designed to handle up to 1500 ftlbs of torque and is billet machined and precision balanced for ultimate strength. I really hope thats what it is, and that the noise will go away when replaced. Unlike other manufacturers, bd is reusing the stock flywheel assembly to reduce costs and unnecessary part changes. All duramax tm engines are manufactured to very close tolerances to meet the durability and reliability standards. The one i heard was on my brothers 89 34 ton ext cab with a 350. Oil filter was clean no silver in the filter that was noticeable on the element and very very little residue on the filter mag. Well my 2004 lly duramax has developed a loud knock. I just thought id post a short video of what a cracked flexplate on a 6. After they checked it out, they said it was a cracked flex plate between the tranny and engine, and that this is a known issue with gm.

Powered by the lmm duramax 365hp660tq coupled to the mw7 allison 6speed through the np1 np263xhd transfercase. Noise in my chevrolet silverado sounds like flywheel. The sound is very similar to a bad engine rod and is often misdiagnosed. It bolts to the end of the crankshaft and the transmissions torque converter bolts to it. Over the years these trucks have been really good performers, but they do have some common problems. Fits 0615 lbz, lmm, lml this replaces the factory flywheel flex plate with a improved bil let steel one piece design and eliminates the heavy cast iron and the weak stamped steel flex plate. Give a guess in the comments section and stay tuned. In the past few days my 94 has been knocking while in gear and at low rpms. Just got off the phone and was told it has a cracked flywheel. I hadnt removed the inspection plate yet to see if i had a broken tq converter bolt or a cracked flex plate.

Proposed the issue was the flex plate rather then the engine. Thought they saw a crack in flex plate, i have a warranty that covers the flex plate, i had to authorize the removal of trans for further inspection, but the shop said the spacer looks bad and they found no cracks. Duramax 0104 lb7 billet flex plate socal diesel inc. I told them for the amount of miles these parts should not have broken, etc.

When additional horsepower and torque are added to your duramax, you run the risk of cracking the stock flexplate. I did check the converter bolts and they were good. I only say this because it happened to my 2000 and the dealer told me i had an engine knock and that my engine was toast. These units are a direct boltin and fit any oem or aftermarket torque converter. High to low socal diesel billet flex plate 20012005 lb7lly. The sound is very similar to a bad connecting rod and is often misdiagnosed. Those flywheel bolts are really tight, and they require a 14mm allen wrench driver. I took in my 2005 chevrolet duramax diesel to dealer with cracked fly wheel and flex plate. While various versions of the engine have surfaced over the years, all generations of the duramax are based on the same foundation. A flex plate with a crack like you describe can break at any time for any reason, and is a prescription for leaving you stranded, even if you are trying to be gentle with it. If you only tow 5% of the time and this is a daily driver, then a 34 ton might be ok but it is no 12 ton as far as comfort and mileage. If a thud is heard, the flywheel may be loose or damaged. Your flexplate could also be cracked as well, certainly not unheard of on a 6. When a flexplate cracks, it often produces a loud knocking noise as it rotates.

And probably, some lessthanawesome mechanics might even mistake said noise for an engine knock wristpin knock. Dec 28, 2004 right off the bat, they said it didnt sound like piston slap. A cracked flexplate knock can sound exactly like a rod knock however no matter what you do to the engine you can not find a way to get it to stop. Engine build variation from engine to engine contributes to differences in perceived volume. If so, more than likely its just the triple clutch setup makeing noise in the converter. With increased torque from the engine, it can crack andor rip the center out of a stock flex plate. As a result, this can cause the flexplate to wobble. How to know if a flexplate is warped it still runs. In this video i talk about a noise coming between the engine and transmission.

Injector knock or cracked flexplate diagnosis series featuring my 2009 chevrolet duramax lmm dually. The reason for the sound involves the flexplates location and its function. Loose torque converterto flywheel or flywheel tocrankshaft bolts will sound similar to bearing knock. This is a must with the high torque in conjunction with a better designed torque converter that can transfer the torque with no. The classic and most obvious symptom of a cracked flexplate involves the sound it makes while the engine is running.

It made a knocking sound similar to a cracked flexplate. I was told by several people it could be a cracked flex plate. Oil pressure is good, 45 at idle up to 75 at 4500 rpm. No noise what so everi took the trans out and the flex plate looked like brand new with no cracks. Finally, you might notice rhythmic clunking or grinding noises. Than there is a chance that it could be a cracked flexplate that is causing the noise. All 6600 duramax tm diesel engines have this condition. Chevrolet silverado 1500 questions loud knocking noise 5. Apr 22, 2018 i just thought id post a short video of what a cracked flexplate on a 6. Even though the 0610 duramax s are equipped with slightly stronger, forgedsteel rods than what was used in the 0105 engines lb7 and lly, the problem moves upward, into the pistons, on the lbz and lmm engines.

To determine if the flexplate is cracked for sure the transmission would have to be removed to inspect it. The truck has a lift kit and dealer told me not covered under gm warranty, etc. If you have ever changed a flywheel then the procedure will be familiar. Ats diesel billet flexplate for gm duramax 20012004 6. My uncle thinks it may be a cracked flex plate from how i described it to him. Duramax lmm diesel engine knock unplugging injectors manually. The sun coast a1bfp billet flex plate for your 20012005 gm 6. Injector knock or cracked flex plate diagnosis w 2009 chevrolet duramax lmm dually. Featured items newest items bestselling alphabetical.

The flex plate replaces the flywheel in automatic transmission cars. I had a 86 k20 t400 350 gasser company truck that would break the center out of the flexplate every 5000 miles. Rotational knocking when engine is warm duramax tuning, logging, and gauges. Duramax 1116 lml billet flex plate socal diesel inc. I have a loud knocking noise coming from the engine. I have had a lly with a cracked piston, the blowby gave it away. I have had one do that before, and it sounds exactly like what you are describing. It threw me off because it sounds like its coming from motor by the fire wall from inside unless you stick your head by the floor you can hear it. To test for a loose or cracked flywheel, operate the vehicle at approximately 32 kmh 20 mph and shut off the engine. Common issues and problems we see in the shop with the lb7 6.

Random rattling noise from bellhousing area the truck stop. Common issues and problems we see in the shop with the lb7. Designed to handle up to 1500 ftlbs of torque, the new duramax black oxide coated flexplate is corrosion resistent to prevent hydrogen embrittlement, billet machined and precision balanced for ultimate strength. Loose flexplate converter bolts make a nasty sound similar to a rod knock, but immediately go away as soon as you try to accelerate the mass. Usual failure mode is the crankcase bolts or the torque converter bolts work loose, allowing the parts to start moving in different directions, the clicking sound you heard. Socal duramax billet flex plate danville performance. Cracked fly wheel usually gets louder as it gets hotter, or under heavier load. Sounds like cracked flex plate, damaged torque convertor or transmission related. I had posted a similar question when i first got my vehicle around sep. To me it sounded like a mad woodpecker somewhere under the truck. Sometimes you can actually get a little movement of the flywheel just before the torque converter moves. Jan 19, 2011 i just put a flex plate in my hd 2500 6. A loose or cracked flywheel will produce an irregular thud or click.

Put a new flex plate in, it must have been a newer style but still worked. The truck still runs great and doesnt effect performance at all. If the alarm has been activated, it must be reset in order to turn it off. I wasnt even thinking the fly wheel since i hear the noise the best with the hood open. Those factors ensure that when the engine starts and the driver puts it in. Injector knock or cracked flexplate diagnosis w 2009 chevrolet duramax lmm dually. A sfi certified flywheel flex plate is re quired on drag. It runs fine in park but in any other gear with my foot on the brake it has a very noticeable, almost loud knocking sound. Most cracked piston scenarios play out at power levels well beyond stock roughly 650 to. Im not ruling out possibly a cracked flex plate but im leaning away from it cause the noise is from up front. Many models of the dodge durango are equipped with a factoryinstalled alarm system that monitors sensors mounted on the vehicle to detect unauthorized entry attempts. Aug 04, 2011 loose flexplate converter bolts make a nasty sound similar to a rod knock, but immediately go away as soon as you try to accelerate the mass.

Dec 19, 2017 dont think bearings is an issue then, when bearings go, the knock will get louder as oil thins out from heat, you will have less oil pressure also. This saturday i slid the torque converter off the flex plate and got the engine hot. Now finally invesigated a slight knock that i couldnt tell if it was normal diesel sound or not. This flex plate is twice as thick as stock and has passed the stringent 29. A loose bolt will hollow out the hole, and can cause a crack from the hole toward the middle real hard to see.

I would take that cover off and turn the flywheel by hand to see if you can see a loose bolt. The reason for the sound involves the flexplate s location and its function. Broken or loose bolts on the crankshaft end of the flexplate, or on the torque. Give a guess in the comments section and stay tuned for pt. A loose bolt on a flexplate or a crack between its bolt holes. A couple of weeks ago i bought a 2002 chevy 2500hd crew cab diesel lb7 with 118,000 miles off of a private seller. The rear cover came loose pretty violently and ended up ruining the dowels in the upper pan anyways. I had the transmission rebuilt thinking it was the flywheel or torque convertor and wasnt the problem but transmission was in bad shape. Just crawled under and were the tranny hooks up to the motor it has a knock, like its dieseling. A mirror andor opaque color laser cut acrylic design is permanently attached to the stainless steel surface to create a threedimensional finish. Fuel knock and black smoke after replacing injectors. I took in my 2005 chevrolet duramax diesel to dealer with. At first i thought it was comin from the top but when i get under it its alot louder sounds like its comin from the oil pan. Mine cracked all over the place on me, didnt know it until i was doin some instals though and when i removed the starter i seen.