Diagnosing cracked flex plate 454

The flex plate replaces the flywheel in automatic transmission cars. This item scat crankshafts fp454sfi flexplate for big block chevrolet. There may be some external clues that will point more one way than another especially since the 454 was made for 30 some years. Engine overheating can occur if a cracked engine block is severe enough to allow engine antifreeze to leak out of the engine, which causes engine temperatures to rise, and the engine to overheat. Slight misalignment may only cause a single flexplate to break in the life of the vehicle. Ways, some of which require a wellequipped workshop in order to diagnose but some common ones are. Cracked flexplates arent as rare on these vans as they are on other cars. Symptoms of a bad or failing crankshaft harmonic balancer. Dude, looking at your questions for the past 2 weeks, you should give up trying to fix your own vehicle. Scat crankshafts fp454sfi flexplate for big block chevrolet. And like gearcruncher said, the flex plate does have a spacershim and maybe they didnt install it.

Has anybody had any luck welding up cracks in a 6 cyl flex plate. I had a cracked flex plate on my 1999 land rover discovery 2, but before i knew what it was i had trouble finding information on diagnosing what it could be. The flex plate dampens this vibration from the engine to the driveline and reduces the noise that we hear. There should be 2 dowels, one on each side, to align the bellhousing of the transmission with the engine block. More severe misalignment can break a flexplate in 15,000 to 30,000 miles. 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. I have a chevy 454 motor my flex plate and starter are not close enough to start the truck makes alot of noise answered by a verified classic car mechanic. Mine was cracked all the way around the center mounting holes shop the new one is like. Like bill mentioned, there is a proper torque sequence to follow to tighten the flex plate to the crankshaft.

Hope this helps others trying to diagnose this engine noise. It is critical that you use the correct design for your specific engine application. It sounded like a big end knock at idle, went quiet when put into drive. A dropped bolt will definitely make noise but the noise typically doesnt last long since something breaks. External 168 teeth balance chromoly steel flexplate for chevy 454 197090, early.

Flexall vitamin e enriched pain relieving gel, 4 oz. Then whom ever replaced the fp before me didnt catch the peened bellhousing and tightened it down causing a alignment problem. A loose bolt on a flexplate or a crack between its bolt holes. I have a chevy 454 motor my flex plate and starter are not. Sounds just like when the flex plate on my 200 tdi auto was buggered. Cracked flexplate how can i tell the chrysler minivan. Also, does the tranny need to be dropped to replace the plate, or can i simply unbolt it from the torque converter and throw in a new one. As its name suggests, the flex plates thinness and light weight allows it to flex and. The other task the flexplate must perform is joining the crankshaft to the torque converter. Chevy big block flexplate 168t external balance 10185034. He was totally not expecting the cause of the valve train noise to be driveline related, namely a cracked flex. Fp454 oem part number fp454 additional information.

I just thought id post a short video of what a cracked flexplate on a 6. Mine was cracked all the way around the center mounting holes shop the new one is. Any metal shop can make you one using the cracked one as a pattern. Flexplate technology and choosing the flexplate for you. There are several telltale signs that there is a problem with either the. Carburetor tools ignition tools and testers trailer tools diagnostic tools lube. Pulled the passenger rocker off, check to see if there were any broken springs but everything seems to be fine. A vital part of an automobile engine equipped with automatic transmission, a flexplate consists of a piece of thick sheet metal that bolts to the crankshaft and. Descriptions of the sound include clanking, chirping and a light knocking. So i figured i had a broken crankshaft and disassembled the. As a result, this can cause the flexplate to wobble.

After checking the flexplate id pull the valve covers to see if theres damage up top that is preventing the engine from turnung over. I have also seen the alignment dowels go missing between the bell housing and the engine block. They do run hotter than other small blocks because they are a siamese bore,no space in the block casting between the cylinder bores. Flywheels and flexplates chevrolet performance offers both internally and externally balanced flywheels and flexplates. A cracked flex plate is almost always a sign of other problems. Great for anyone who suffers from arthritis, bursitis, tendonitis, backache, muscular tension, strains, sprains, bruises and cramps. Chevrolet performance 10185034 chevrolet performance flexplates compare flexplate, 168tooth, external engine balance, 1piece rear main seal, chevy, big, block, 454 7. Flywheel flex plate flywheel flex plate 8 454 7 4l fits 73 90 chevrolet forward control 18195. Mine was inspected through the little inpection hole at the bottom looking for radial cracks, but on full engine removal found it has split into two concentric rings, drive only.

Cant pinpoint the source of the noise im thinking either the flexplate or torque converter its a 2000 5. I have a tired 366 chevy big block in one of my trucks. Do i have have to remove the tranny or can i just loosen the torque converter and slide it back enough to get to the flex plate. My uncle thinks it may be a cracked flex plate from how i described it to him. The first cracked fp for me i ignorantly assumed the missing torque converter bolt was the problem so i missed the bellhousing problem. Top rated products in automotive replacement flexplates. The flexplate can crack or warp due to an out of balance engine or torque converter. Rattles at idle but the force of driving jams the bits together so no rattle when driving. Shr trans,ati flex plate,ati overdrive pulley,getrag 3. For warranty information about this product, please click here. We use cookies to give you the best possible experience on our website.

Symptoms of a cracked flexplate general discussion. The starter is an electric motor that spins a small gear. As i start to move the knock speed increases slightly with rpm but then stops and the engine runs fine. The plate in question is bolted to the flywheel and transfers power to the input shaft of the transmission via a splined coupling. Pull lower pan,check rod movement,or remove bearing cap. The crankshaft harmonic balancer is a device connected to the front of an engines crankshaft, usually built into the crankshaft pulley. Lots of experience with 427s and 454s but not a lot with a 366. I discoved the flex plate was cracked in several spots.

Sfi 168 tooth sfi 168 tooth big block chevy 454 502 flexplate 1991 up bbc heavy duty 1 piece. Similar in function to a flywheel in manual transmission engines and called a flexplate due to its expansion, or flexing, during the operation of the engine, flexplate. I have talked to other mechanics about this and i have changed the timing chain and the flex plate to the trans and the fuel pump, and i still had the noise. Pics of a cracked flex plate peachparts mercedesbenz forum. The teeth around the edges can also break off, causing. Fiy damper plate replacement first of all, the signs that a damper plate is going bad will be a knocking noise coming from the bell housing of the transmission. 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. This video demonstrates the sound, diagnosis and solution to what sounded like a rod knocking on a 1999 toyota 4runner with a 3.

It bolts to the end of the crankshaft and the transmissions torque converter bolts to it. The weight on the flywheel is critical,or you can use a 350 flywheel with a balance plate sold by summit or others. Theres also a chance they didnt gradually torque the bolts that hold the flex plate to the torque converter and maybe its not balanced. When stripped down, the plate had split around all 6 bolt holes.

Its purpose is to absorb and reduce harmonic vibrations from the engine as the crankshaft rotates, as harmonic vibrations at high engine speeds can cause accelerated wear and damage to the components. Prw 1845400 sfirated external 168 teeth balance chromoly steel flexplate for chevy 454 197090, early. The sound is very similar to a bad connecting rod and is often misdiagnosed. Flexall provides powerful soothing relief to joints and muscles. If you really stop and think about a highhorsepower pro modified car planting the tires and launching to a subone second 60foot times, realizing there is a small, relatively thin plate of metal transferring 4,000 horsepower rearward at one of the key junctions in the powertrain, you begin to see the. As he had some other work to be done on his truck that required some professional expertise, he took the truck to a gm dealer workshop. I investigated it and it sounded like it was coming from the. Most likely you will have to find a casting number on the block to know for sure. Engine antifreeze circulates deep within an engine block, in and around the main engine combustion chambers. Weve had a few forum members get broken flex plates in the last few years. Its possible the rear exhaust manifold or even the crossover pipe cracked and developed a leak. There are a crapload of different flexplates for the 454 since it came with th350th4004l80etc. I have heard that a 366 and 454 flywheel have the same weights on the flywheel and are inter changeable but no one i talk to is sure 100%.

Typically this occurs because the torque converter bolts come loose, or if the transmission was ever removed and the bolts were not torqued properly this will. Proper transmissiontorque converter installation duration. I had the usaf metal shop make me one from a scrap of aircraft grade stainless. If anything thing goes wrong in this process, it can cause the engine not to start at all. Pulled the driver side valve covers off and rockers seem tight and no bent pushrods or broken springs. Questions bmw bmw 528i 2000 bmw 528i is a cracked flexplate. Atp z166 automatic transmission flywheel flexplate product image. I went from an externally balanced 454 to a internally balanced stroker 489 which. Those factors ensure that when the engine starts and the driver puts it in drive, the cracked flexplates movement will create a noise. Allstar performance all26825 168t 454 standard external balance flexplate. The flex plate has a ring gear around its circumference, which mates with the starter motor when you start your car. The flex plate is a metal disk that mounts the torque converter in an automatic transmission to the rear of the engines crankshaft.

This may occur in worn engines or engine that have been poorly rebuilt. Patc sells billet flexplates, performance flexplates. Bbc big block chevy 454 flexplate flex plate 168 tooth external balance. A serious crack can cause a mild vibration when driving, so can a faulty torque converter. A vital part of an automobile engine equipped with automatic transmission, a flexplate consists of a piece of thick sheet metal that bolts to the crankshaft and torque converter. Hughes performance hp3994 sfi rated hd flexplate with external balance for big block chevy.