Differential Rotation (under car video)
Thread Starter
Le Mans Master
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From: Van Steel Corvettes
St. Jude Donor '12-'13
Differential Rotation (under car video)
Is it normal for the diff to rotate slightly? Is this what the ZFdoc c-beam plates eliminate, or did I bust yet another c-beam bolt?
I'll be crawling under the car this weekend to check regardless, but wanted to see what y'all thought.
I'll be crawling under the car this weekend to check regardless, but wanted to see what y'all thought.
Thread Starter
Le Mans Master
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From: Van Steel Corvettes
St. Jude Donor '12-'13
Thanks. Hell I'm running 34psi now. Not even rolling over all the way to the side groove yet (technical term is escaping me at the moment). Actually a good distance from it.
Certainly didn't over tighten them, at least I didn't. Only changed the rear bolts a few months ago.
Certainly didn't over tighten them, at least I didn't. Only changed the rear bolts a few months ago.
Last edited by shakedown067; Mar 15, 2013 at 04:33 PM.
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CTS-V, camera mounted sideways...
Last edited by Tom400CFI; Mar 15, 2013 at 06:01 PM.
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St. Jude Donor '09 thru '20
These are great videos, but the FSM calls for 59 ft-lbs at the differential, and 37 ft-lbs at the transmission.
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Talking about the mounting bushings on the bat wing and suspension. If parts don't give they break. Think about it, diff & drive line connected to trans & bolted to the engine which moves quite a bit under hard throttle.
Last edited by kimmer; Mar 15, 2013 at 07:16 PM.
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From: Park City Utah
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I gotta agree with Mr Tom...
the C-beam is solid mount at both ends to prevent movement in that way.. the batwing ears are 90 degrees to that so they would have to be gone to allow that movement.
So...the batwing and trans should move together...if at all but it has to be very limited..only what the diff mount ears would allow and that ain;t much.
I'd start by looking hard at the trans bolts in the beam...rear end bolts too.. I'd even take a close look at the lattice of the batwing! thats tweaking way too much for aluminum to be happy...thats a loose or broken mount or possibly broken batwing the way it twist with the torque.
somethins not right !
the C-beam is solid mount at both ends to prevent movement in that way.. the batwing ears are 90 degrees to that so they would have to be gone to allow that movement.
So...the batwing and trans should move together...if at all but it has to be very limited..only what the diff mount ears would allow and that ain;t much.
I'd start by looking hard at the trans bolts in the beam...rear end bolts too.. I'd even take a close look at the lattice of the batwing! thats tweaking way too much for aluminum to be happy...thats a loose or broken mount or possibly broken batwing the way it twist with the torque.
somethins not right !
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If those bushings are rotten it will move. Those bushings are a PITA to replace.
Pro
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From: Texas
Sure doesnt look right to me. Hard for me to believe the c beam can deflect that much without something being loose or broken.
for it to move like that I would think it would be at diff end of the c beam.
Very neat video
for it to move like that I would think it would be at diff end of the c beam.
Very neat video
Thread Starter
Le Mans Master
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From: Van Steel Corvettes
St. Jude Donor '12-'13
Diff doesn't deflect left or right, so talking to Paul at Van Steel, we've ruled out bushings! Will let you know when I check out the c-beam bolts.
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That may very well be what's missing! STOCK PARTS ! It would be interesting to put at least the stock lower control arms back in the car and do the same "visual". Beam plates are conversational, but with one video in "the can" I believe I'd go about replacing everything that has "heim joints" with conventional bushing stock parts and try it. There's nothing to be lost and it could be very educational. If the "heim joints" create this issue there's no doubt that there's wear being created at the rear and front beam mounts and the "beam plates" would certainly aid in the constant re-torquing that's going to be required. This might be a very good reason to consider the beam plates. It would seem that what's been documented here would indicate there's constant wear on both the transmission and differential mounting bolt bores.
Do you have all of the OE parts still?
Do you have all of the OE parts still?
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I don't see how the batwing bushings could deflect in that direction, that much. Look at the angle of deflection...not just the amount in inches...
How could heim joints for the suspension possibly have an effect on this issue??
The issue is the rearward rotation of the diff, under acceleration. The suspension (no matter how it's secured) has no impact on those forces. It's ALL about the C-beam. That is 1 of the 2, C-beam's jobs, is to prevent the rearward or forward rotation of the diff, under acceleration and deceleration, respectively. LONG before slapping stock, mushy bushings back into the suspension, as a test, I'd inspect the item who's job is to prevent that motion. I'd inspect the C-beam.
That may very well be what's missing! STOCK PARTS ! It would be interesting to put at least the stock lower control arms back in the car and do the same "visual". Beam plates are conversational, but with one video in "the can" I believe I'd go about replacing everything that has "heim joints" with conventional bushing stock parts and try it. There's nothing to be lost and it could be very educational. If the "heim joints" create this issue there's no doubt that there's wear being created at the rear and front beam mounts and the "beam plates" would certainly aid in the constant re-torquing that's going to be required. This might be a very good reason to consider the beam plates. It would seem that what's been documented here would indicate there's constant wear on both the transmission and differential mounting bolt bores.
Do you have all of the OE parts still?
Do you have all of the OE parts still?
The issue is the rearward rotation of the diff, under acceleration. The suspension (no matter how it's secured) has no impact on those forces. It's ALL about the C-beam. That is 1 of the 2, C-beam's jobs, is to prevent the rearward or forward rotation of the diff, under acceleration and deceleration, respectively. LONG before slapping stock, mushy bushings back into the suspension, as a test, I'd inspect the item who's job is to prevent that motion. I'd inspect the C-beam.
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