auto conversion and engine damage
Former Vendor
Joined: May 2003
Posts: 2,173
Likes: 2
From: Dallas Texas
while the torque tube is bolted, the driveshaft is not. Its in a floating bearing housing in the torque tube at the front of the engine. it can expand at different rates vs the torque tube. There is a lot going on there, for sure.
I have a fresh crank with the proper bobweight out of an LS7 that was sent out and inspected and mag'ed if you are interested.
I have a fresh crank with the proper bobweight out of an LS7 that was sent out and inspected and mag'ed if you are interested.
Thread Starter
Melting Slicks
Joined: Dec 2011
Posts: 2,690
Likes: 116
From: Richmond area Va
i think the machine shop said they need to take .007 off the crank thrust wall, which would make the need for a .014 bearing from outside to outside of thrust flange.
i am betting that does not exist, or anything close to it?
Louis, thanks for the offer. feel free to pm me.. tho probably going to have to take the dragonslayer option pending a pm response about it's specs.
thanks guys.
i found today a thread about this exact same thing happening to more than one ''innocent bystander'' on here.. there MUST be a way to prevent this.
i am betting that does not exist, or anything close to it?
Louis, thanks for the offer. feel free to pm me.. tho probably going to have to take the dragonslayer option pending a pm response about it's specs.
thanks guys.
i found today a thread about this exact same thing happening to more than one ''innocent bystander'' on here.. there MUST be a way to prevent this.
Thread Starter
Melting Slicks
Joined: Dec 2011
Posts: 2,690
Likes: 116
From: Richmond area Va
i have an idea for a separate fix.. not that it will make it to production with me not being a company.. anyways.
nick i agree that rubber couplers wont make it at high hp. its my opinion with ongoing review that the alum couplers not being flat, created a wobble/vibration that tore up the bushing in the converter, and cracked the spline drive. but did not necessarily cause the thrust bearing failure, tho it may have exaggerated it.
i think at this time the rpm billet slip coupler is a must-have. especially once you choose to not run the factory front flex plate for strength or sfi regulations. you have to have something to accommodate the movement.
i believe so much so that i don't think any of the above should be sold without the other... it has and will cost people engines. any of the parts should also come with a warning/disclaimer if you choose not to install the set (if was my business to sell them)
nick i agree that rubber couplers wont make it at high hp. its my opinion with ongoing review that the alum couplers not being flat, created a wobble/vibration that tore up the bushing in the converter, and cracked the spline drive. but did not necessarily cause the thrust bearing failure, tho it may have exaggerated it.
i think at this time the rpm billet slip coupler is a must-have. especially once you choose to not run the factory front flex plate for strength or sfi regulations. you have to have something to accommodate the movement.
i believe so much so that i don't think any of the above should be sold without the other... it has and will cost people engines. any of the parts should also come with a warning/disclaimer if you choose not to install the set (if was my business to sell them)
Le Mans Master
Joined: Oct 2003
Posts: 8,863
Likes: 86
From: PA
St. Jude Donor '08
Good info ...
When installing new Tilton clutch I pulled out shaft out of torque tube to inspect and rubber couplers look good. I didn't expect to find any issues as low miles and very little track time. As with most parts life expectancy is greatly shorted with traction.
If track visits are occasional then I see no problem running rubbers couplers on a nice DSS shaft with stock flex plate cone/coupler. Tell me if you disagree.
When installing new Tilton clutch I pulled out shaft out of torque tube to inspect and rubber couplers look good. I didn't expect to find any issues as low miles and very little track time. As with most parts life expectancy is greatly shorted with traction.
If track visits are occasional then I see no problem running rubbers couplers on a nice DSS shaft with stock flex plate cone/coupler. Tell me if you disagree.
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Thread Starter
Melting Slicks
Joined: Dec 2011
Posts: 2,690
Likes: 116
From: Richmond area Va
yay crank will be done today.
remove drivetrain, remove engine, disassemble (free)
new crank (used, clean) $625
new clevite hx bearings $200
reverse balance crank $225
reuse all gaskets, fasteners (free)
oil, filter $50
reassemble engine, reininstall engine, reinstall drivetrain (free)
2 months of car sitting.. hmm $?
total costs $1100 doing the most affordable way possible.
please take my word for it on this subject.. you don't want this to happen to you.
remove drivetrain, remove engine, disassemble (free)
new crank (used, clean) $625
new clevite hx bearings $200
reverse balance crank $225
reuse all gaskets, fasteners (free)
oil, filter $50
reassemble engine, reininstall engine, reinstall drivetrain (free)
2 months of car sitting.. hmm $?
total costs $1100 doing the most affordable way possible.
please take my word for it on this subject.. you don't want this to happen to you.
Burning Brakes
Joined: Apr 2009
Posts: 762
Likes: 2
From: Kopavogur in Iceland
damn that´s awful
but i´m trying to understand how was your driveline setup when this happened what aftermarket parts and what GM parts where you using
and how are you gona hooke it up now.
good luck
Baezi
but i´m trying to understand how was your driveline setup when this happened what aftermarket parts and what GM parts where you using
and how are you gona hooke it up now.
good luck
Baezi
Melting Slicks
Joined: Oct 2003
Posts: 2,859
Likes: 4
From: Greensboro NC
Sorry to hear about this. This should be all over the forum. I have just installed a new 402 A4 and replaced the couplers with six shooters by prothane. Has anyone had this failure happen with the prothane couplers installed?
Melting Slicks
Joined: Jan 2009
Posts: 2,420
Likes: 6
From: Miami FL
some unrelated pictures till i measure the crank movement this evening
i ran 4 passes before the engine started grinding to a stop while idling.. so if i was to skip ahead a few thoughts, that's how long it takes before you start scuffing the block with the crank
the fact that it 'seems' ok with the crank unclamped to the drivetrain makes sense.
also check out this vid i found, cool
http://www.youtube.com/watch?v=YEfqKoilLkI
i ran 4 passes before the engine started grinding to a stop while idling.. so if i was to skip ahead a few thoughts, that's how long it takes before you start scuffing the block with the crank
the fact that it 'seems' ok with the crank unclamped to the drivetrain makes sense.also check out this vid i found, cool
http://www.youtube.com/watch?v=YEfqKoilLkI
Melting Slicks
Joined: Feb 2006
Posts: 2,007
Likes: 1
From: Eastern PA:ECS Paxton Novi 1500(676rwhp,585tq on stock engine),LG headers, 410's, Corsa Sports, ECS Alky Kit
St. Jude Donor '08-'09
some unrelated pictures till i measure the crank movement this evening
i ran 4 passes before the engine started grinding to a stop while idling.. so if i was to skip ahead a few thoughts, that's how long it takes before you start scuffing the block with the crank the fact that it 'seems' ok with the crank unclamped to the drivetrain makes sense.
also check out this vid i found, cool
http://www.youtube.com/watch?v=YEfqKoilLkI
i ran 4 passes before the engine started grinding to a stop while idling.. so if i was to skip ahead a few thoughts, that's how long it takes before you start scuffing the block with the crank
the fact that it 'seems' ok with the crank unclamped to the drivetrain makes sense.also check out this vid i found, cool
http://www.youtube.com/watch?v=YEfqKoilLkI
5th Gear
Joined: Sep 2012
Posts: 5
Likes: 0
From: COLUMBUS GA
Beat me to it^^^^^ . But I just had this issue with a friend of mine. Strange thing was it just toss the serp belt at high rpm all the time. When he brought it to me it was allready toast. We are re doing his engine now the crank walk so bad it split the mains and slightly bent the rods, And cut into the cylinder walls. Im going to call rpm for the fix. Also Im going to show him this tread. Good luck Dave sorry bout the hi jack.
Melting Slicks
Joined: Oct 2003
Posts: 2,859
Likes: 4
From: Greensboro NC
I am pulling my drivetrain back out. I am not taking a chance with the Prothane Six Shooter Couplers. I am wondering if I should go back to stock OEM couplers or what options I would have. Is this RPM fix a slip spline coupler that stays loose for movement? Or is it just replacement rubber couplers with the use of OEM spline?
http://www.rpmtransmissions.com/drivetrain-upgrades
http://www.rpmtransmissions.com/drivetrain-upgrades
Last edited by JeremiahsC5; Feb 18, 2013 at 08:06 PM.
