Cracked Bell Housing
Thread Starter
Racer
Joined: May 2004
Posts: 370
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From: Orlando FL
Cracked Bell Housing
Car was in a crash that impacted in the LF and resulted in L frame rail replacement. Right rail was pushed right a few mm but pulled back in before L was replaced. During repair of a blown clutch slave cyl., they dioscovered the BH was cracked and will require replacement.
Question is, should I be concerned about other engine areas that may seem visually intact but may, based on this new finding, now be suspect? I'm wondering if the slave was blown as a result of the BH incident, and not due to clutch breakage at the master as previously suspected. If so, what took the hit, motor mounts and block or other drive train components like torque tube or flywheel, etc.? If the block took a tweaking sufficient to break the BH, should I worry about cracks or internal block damage? Is the BH an engineered weak point that broke when the axis shifted slightly right and I'm being overly paranoid?
I realize we all want our cars as safe and sound as they can be, but I do tend to push mine from time to time and explore the limits (auto-X and HPDE events), and don't want a surprise at a bad moment.
If this was your car, what else would you want looked at?
Thanks,
Jim
Question is, should I be concerned about other engine areas that may seem visually intact but may, based on this new finding, now be suspect? I'm wondering if the slave was blown as a result of the BH incident, and not due to clutch breakage at the master as previously suspected. If so, what took the hit, motor mounts and block or other drive train components like torque tube or flywheel, etc.? If the block took a tweaking sufficient to break the BH, should I worry about cracks or internal block damage? Is the BH an engineered weak point that broke when the axis shifted slightly right and I'm being overly paranoid?
I realize we all want our cars as safe and sound as they can be, but I do tend to push mine from time to time and explore the limits (auto-X and HPDE events), and don't want a surprise at a bad moment.
If this was your car, what else would you want looked at?
Thanks,
Jim
Pro
Joined: Mar 2002
Posts: 632
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From: Enterprise AL
I would want the entire drivetrain looked at, if the impact was sufficient to crack the BH, then it may have been enough to cause other damage to the non-moving support components. The strain that caused the cracked BH could have been transmitted back to the rear by the torque tube and that could mean more trouble back there.
The car must have taken quite a whack to crack the bell housing. If the frame rails were displaced, then the entire drive train has the potential to be out of alignment now, if not replaced or repaired then a few thousand miles down the line things will mysteriously begin to break or wear prematurely.
The car must have taken quite a whack to crack the bell housing. If the frame rails were displaced, then the entire drive train has the potential to be out of alignment now, if not replaced or repaired then a few thousand miles down the line things will mysteriously begin to break or wear prematurely.
Drifting
Joined: Oct 2004
Posts: 1,384
Likes: 8
From: Southwest Virginia
It is pretty common to break the BH in these cars during a crash. I have seen a few, specially in side impacts. If you think about the design the engine is supported on each side in the front and then the differential is supported at the center of the rear of the car. You have a large heavy engine at the front, and a heavy transmission and differential tied together with this light weight aluminum tube and thin light weight cast aluminum BH. So these two heavy items hanging out at the ends can stress these light weight (weak) items in the middle while being shook around in a crash. I would not worry about the engine or transmission, but would look real close at the torque tube.
Do you have pictures of the crack? I'm rebuilding a Z06 now that was hit fairly light in the rear. I have looked at my BH very close and don't see any cracks but would like to see exactly where your BH cracked. The last one I seen was on an automatic car side impact and it broke a circle crack all the way around the front BH just ahead of the torque tube.
Do you have pictures of the crack? I'm rebuilding a Z06 now that was hit fairly light in the rear. I have looked at my BH very close and don't see any cracks but would like to see exactly where your BH cracked. The last one I seen was on an automatic car side impact and it broke a circle crack all the way around the front BH just ahead of the torque tube.
Le Mans Master
Joined: Jul 2002
Posts: 7,370
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From: Slave to the evil empire
Cruise-In V Veteran
St. Jude Donor '04
Originally Posted by SpeedyZ
It is pretty common to break the BH in these cars during a crash. I have seen a few, specially in side impacts. If you think about the design the engine is supported on each side in the front and then the differential is supported at the center of the rear of the car. You have a large heavy engine at the front, and a heavy transmission and differential tied together with this light weight aluminum tube and thin light weight cast aluminum BH. So these two heavy items hanging out at the ends can stress these light weight (weak) items in the middle while being shook around in a crash. I would not worry about the engine or transmission, but would look real close at the torque tube.
but if your really worried about it tell them that you won't accept your car after the work is completed until you can take a lengthy test drive
Thread Starter
Racer
Joined: May 2004
Posts: 370
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From: Orlando FL
Originally Posted by SpeedyZ
Do you have pictures of the crack? I'm rebuilding a Z06 now that was hit fairly light in the rear. I have looked at my BH very close and don't see any cracks but would like to see exactly where your BH cracked. The last one I seen was on an automatic car side impact and it broke a circle crack all the way around the front BH just ahead of the torque tube.
Meanwhile, I'll be harping on them to triple check the torque tube and all other drivetrain components.
Team Owner
Joined: Mar 1999
Posts: 22,025
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From: At the beach in little Rhody
Unfortunately, most of these parts are cast aluminum which do not survive well when subjected to a shock situation. I would check over the cast pieces very closely, even to the point of doing some dye penetrant testing for surface cracks. Look hard in the area of sharp corners or where the casting goes from a thick to thin section. I would also take a look at the pilot bearing, which may have taken a good load from bending in the torque tube. Look at the rear seal cover as well while the bell housing is off. You may need to get someone from a machine shop to do the dye penetrant testing. Good luck.
