Consequence of a rear end breaking exiting under power?
01-30-2007, 11:53 AM
#1
Le Mans Master
Thread Starter
Consequence of a rear end breaking exiting under power?
Circumstances:
Is the above an indication of a right side half-shaft failure
or perhaps the differential?
.
Past the apex of a 70º left turn, while a car is accelerating
and just starting to move off the outside kerbing back toward
the main portion of the track, it begins to oversteer slightly
(more sharply to left) and then arcs hard to the right and drives
nose first into adjacent Armco.
The car was in traffic and cars ahead/after were travelling at
similar velocity and cornering attitude without issue. The oversteer
started out as nothing more than a wiggle as the rear stepped out
a bit. The driver counter-steered and may have been at or close
to full opposite lock. The speed of the transition and the nearness
of the barrier meant contact was inevitable, even though the brakes
were applied (the wheels at lock-up just before impact.)
Question:and just starting to move off the outside kerbing back toward
the main portion of the track, it begins to oversteer slightly
(more sharply to left) and then arcs hard to the right and drives
nose first into adjacent Armco.
The car was in traffic and cars ahead/after were travelling at
similar velocity and cornering attitude without issue. The oversteer
started out as nothing more than a wiggle as the rear stepped out
a bit. The driver counter-steered and may have been at or close
to full opposite lock. The speed of the transition and the nearness
of the barrier meant contact was inevitable, even though the brakes
were applied (the wheels at lock-up just before impact.)
Is the above an indication of a right side half-shaft failure
or perhaps the differential?
.
01-30-2007, 12:00 PM
#3
Le Mans Master
Thread Starter
Hollinger sequential 6-spd.
Also out of character for the situation: bumper-to-bumper in
traffic as the parade negotiates the turn. The car had cleared
the turn and was in accel mode.
.
Also out of character for the situation: bumper-to-bumper in
traffic as the parade negotiates the turn. The car had cleared
the turn and was in accel mode.
.
01-30-2007, 12:09 PM
#4
Melting Slicks
I am glad it wasn't you. Was this a Corvette? The reason I ask is that when I had worn rubber bushings in the rear suspension, my car developed a snap oversteer under similar conditions when in my opinion, the rear wheel started to toe out under load. If he has heim jointed links, discount this theory.
Last edited by Sidney004; 01-30-2007 at 12:32 PM.
01-30-2007, 12:29 PM
#5
Tech Contributor
I would say suspension related versus halfshaft or differential.
Both could certainly cause that, however....
When a halfshaft goes, there's usually a heck of a racket to go with it as it destroys the rear storage compartment fiberglass on the passenger side, as well as other parts of the body (depending on where the break occured). Lots of other evidence to show what happened as a result.
When the differential goes, you loose power to both wheels or both can lockup. Also much noise and the inside of the differential will look like a grenade went off.
Both could certainly cause that, however....
When a halfshaft goes, there's usually a heck of a racket to go with it as it destroys the rear storage compartment fiberglass on the passenger side, as well as other parts of the body (depending on where the break occured). Lots of other evidence to show what happened as a result.
When the differential goes, you loose power to both wheels or both can lockup. Also much noise and the inside of the differential will look like a grenade went off.
01-30-2007, 08:28 PM
#6
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Circumstances:
Is the above an indication of a right side half-shaft failure
or perhaps the differential?
.
Past the apex of a 70º left turn, while a car is accelerating
and just starting to move off the outside kerbing back toward
the main portion of the track, it begins to oversteer slightly
(more sharply to left) and then arcs hard to the right and drives
nose first into adjacent Armco.
The car was in traffic and cars ahead/after were travelling at
similar velocity and cornering attitude without issue. The oversteer
started out as nothing more than a wiggle as the rear stepped out
a bit. The driver counter-steered and may have been at or close
to full opposite lock. The speed of the transition and the nearness
of the barrier meant contact was inevitable, even though the brakes
were applied (the wheels at lock-up just before impact.)
Question:and just starting to move off the outside kerbing back toward
the main portion of the track, it begins to oversteer slightly
(more sharply to left) and then arcs hard to the right and drives
nose first into adjacent Armco.
The car was in traffic and cars ahead/after were travelling at
similar velocity and cornering attitude without issue. The oversteer
started out as nothing more than a wiggle as the rear stepped out
a bit. The driver counter-steered and may have been at or close
to full opposite lock. The speed of the transition and the nearness
of the barrier meant contact was inevitable, even though the brakes
were applied (the wheels at lock-up just before impact.)
Is the above an indication of a right side half-shaft failure
or perhaps the differential?
.
Bill
03-21-2007, 11:05 PM
#8
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I ain't skeered! See if you kin keep up!
Uh... I notice this is a little old. Has the question been answered by examination of the evidence yet?
I'm curious because, I reckon it takes a whole lot of "ooops" to get from and
to
!!
And isn't it true that
make it hard to steer anyway?
Just thinking out loud... And noticing you didn't mention throttle steer & what effect it had on the situation. Seeing as how that involves the drive wheels, it seems somehow pertinent to the question at hand. Of course, that has to happen sometime before you lock up the brakes. Was the driver counter-steering the slight oversteer or the hard arc to the right?
Sounds to me like a good opportunity for the rest of us to borrow someone else's experience. Or something like that
I'm curious because, I reckon it takes a whole lot of "ooops" to get from and
the rear stepped out a bit
at or close to full opposite lock
And isn't it true that
the wheels at lock-up
Just thinking out loud... And noticing you didn't mention throttle steer & what effect it had on the situation. Seeing as how that involves the drive wheels, it seems somehow pertinent to the question at hand. Of course, that has to happen sometime before you lock up the brakes. Was the driver counter-steering the slight oversteer or the hard arc to the right?
Sounds to me like a good opportunity for the rest of us to borrow someone else's experience. Or something like that