exploding clutch
#1
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exploding clutch
Who's done it? Fess up. You come to a long hill and don't want to shift out of low range so you just put the clutch in and coast, speed picks up, then a loud bang is emitted from under the truck. The clutch over revved and exceeded its rpm rating, causing it to simply explode.
I did the starter a couple weeks ago and found that there was a chunk of the bell housing missing the size of a penny. The bellhousing also had weird chips in it that seem almost like the chip peeled without any scratching to the bellhousing. I couldn't figure how those came from a any outside blow, but I never thought about an impact from the inside...
I did the starter a couple weeks ago and found that there was a chunk of the bell housing missing the size of a penny. The bellhousing also had weird chips in it that seem almost like the chip peeled without any scratching to the bellhousing. I couldn't figure how those came from a any outside blow, but I never thought about an impact from the inside...
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The only way a clutch could over-rev is if the ENGINE was over-revving as well; they're ATTACHED....???
Now, if you were in 2nd gear on a 15% grade and hit 90 mph, I could understand....
Now, if you were in 2nd gear on a 15% grade and hit 90 mph, I could understand....
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#9
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So apparently its the part that isn't attached to the engine that over-revs and explodes.
Last edited by mt_goat; 03-27-2009 at 06:49 AM.
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i've seen some nasty clutches about to fully fail but never failed. Theres some pics of a guys skyline where the flywheel exploded and cut thru anything in its path tho.
edit.
http://pic.phyrefile.com/2007/07/02/780039wy7.jpg
http://pic.phyrefile.com/2007/07/02/780050oh0.jpg
edit.
http://pic.phyrefile.com/2007/07/02/780039wy7.jpg
http://pic.phyrefile.com/2007/07/02/780050oh0.jpg
Last edited by shancerlelby; 03-27-2009 at 09:06 AM.
#13
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The only time you would need to worry about this is in 4low. Think how fast you can go in 1st gear low. Now if you come to a down hill in 4low and 1st gear and just push in the clutch how fast do you think that disengaged clutch disk is spinning at 20MPH? I'm not going to do the math but its fast, probably 8-9000rpm at least. Most clutch disks are only rated to a free spin of 8000rpm, I would think on a 4x4 even lower as most would never go that high.
The Skyline damage was most likely caused my the Flywheel blowing apart. Its fairly common with hi revving hi powered cars. Not really the same as what Matt was talking about. On a 4x4 in Low its much easier to blow up a clutch disk.
Jeremy
The Skyline damage was most likely caused my the Flywheel blowing apart. Its fairly common with hi revving hi powered cars. Not really the same as what Matt was talking about. On a 4x4 in Low its much easier to blow up a clutch disk.
Jeremy
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The only time you would need to worry about this is in 4low. Think how fast you can go in 1st gear low. Now if you come to a down hill in 4low and 1st gear and just push in the clutch how fast do you think that disengaged clutch disk is spinning at 20MPH? I'm not going to do the math but its fast, probably 8-9000rpm at least. Most clutch disks are only rated to a free spin of 8000rpm, I would think on a 4x4 even lower as most would never go that high.
The Skyline damage was most likely caused my the Flywheel blowing apart. Its fairly common with hi revving hi powered cars. Not really the same as what Matt was talking about. On a 4x4 in Low its much easier to blow up a clutch disk.
Jeremy
The Skyline damage was most likely caused my the Flywheel blowing apart. Its fairly common with hi revving hi powered cars. Not really the same as what Matt was talking about. On a 4x4 in Low its much easier to blow up a clutch disk.
Jeremy
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that is what it looks like! hahaha that happened on a couple early powerstroke's because they used a two piece flywheel and they would come apart during high load/performance situations. they replaced them with one piece flywheels and it solved the problems. our clutches are all one piece and seem relatively stout for a smaller engine. When i put in my MC clutch, i made sure to use grade 8 bolts and loctite on the pressure plate. don't want that thing to come off hahaa
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#18
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Now lets say you're in 4lo with a set of 4.7 gears in your transfer case. You're still in 1st, and decide to coast down a hill with the clutch pushed in. you reach a speed of 22.6MPH. Normally, in high your clutch disk would be spinning at 5000rpm, but because it's in low-range, it's now spinning at 23,500rpm! You don't notice this of course, because you have no way of telling how fast the clutch disk is spinning when it's dis-engaged from the motor. Boom.
Those pictures of the Skyline were in Edmonton about a year ago. I believe it was due to a cracked flywheel.
#19
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No, the Pressure plate is bolted to the flywheel, and spins at the speed of the motor. The clutch disk is on the transmission input shaft, and spins whatever speed it's spinning at. A W56 1st gear is 3.9:1. Say you're running 33" tires, and a 5.29 rear-end. You're in gear, and the motor is at 5000rpm. You're doing 22.6MPH.
Now lets say you're in 4lo with a set of 4.7 gears in your transfer case. You're still in 1st, and decide to coast down a hill with the clutch pushed in. you reach a speed of 22.6MPH. Normally, in high your clutch disk would be spinning at 5000rpm, but because it's in low-range, it's now spinning at 23,500rpm! You don't notice this of course, because you have no way of telling how fast the clutch disk is spinning when it's dis-engaged from the motor. Boom.
Those pictures of the Skyline were in Edmonton about a year ago. I believe it was due to a cracked flywheel.
Now lets say you're in 4lo with a set of 4.7 gears in your transfer case. You're still in 1st, and decide to coast down a hill with the clutch pushed in. you reach a speed of 22.6MPH. Normally, in high your clutch disk would be spinning at 5000rpm, but because it's in low-range, it's now spinning at 23,500rpm! You don't notice this of course, because you have no way of telling how fast the clutch disk is spinning when it's dis-engaged from the motor. Boom.
Those pictures of the Skyline were in Edmonton about a year ago. I believe it was due to a cracked flywheel.
i knew i noticed that pic from somewhere
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