auto conversion and engine damage
10-06-2012, 12:00 PM
#1
Melting Slicks
Thread Starter
auto conversion and engine damage?
what is the history on this, and what is the consensus?
i think i may have a problem.. well i know i do, but it only exists with the auto drivetrain hooked up.
i'm starting to think that you may HAVE to use the solid billet slip drive vs. stock spline drive/lock collar with billet driveshaft couplers... and pretty concerned it might have hurt the bottom end in some fashion.
*last night followed the stock procedure for warm up and lock down of spline drive.
today it stalled out within a couple minutes.
went under car, cracked loose spline collar and just snugged it up, idling fine??
i think i may have a problem.. well i know i do, but it only exists with the auto drivetrain hooked up.
i'm starting to think that you may HAVE to use the solid billet slip drive vs. stock spline drive/lock collar with billet driveshaft couplers... and pretty concerned it might have hurt the bottom end in some fashion.
*last night followed the stock procedure for warm up and lock down of spline drive.
today it stalled out within a couple minutes.
went under car, cracked loose spline collar and just snugged it up, idling fine??
Last edited by MIGHTYM0USE; 10-07-2012 at 10:47 AM.
10-06-2012, 01:39 PM
#2
Le Mans Master
We had the regular one in our car when we went 8.5... Is its stalling out like the motor is being pulled down? You will need to change the tune for the auto bc of more load at idle.
10-06-2012, 02:16 PM
#3
Melting Slicks
Thread Starter
did you have solid alum couplers and how tight did you run the spline collar bolt?
yes the motor is being drug down to a stop. unrelated to tune because is still spinning the drivetrain weather the bolt is snug or very tight. its some load into the back of the engine or into the front of the trans
go keep it running when it happens i need about 30% throttle says the scanner, not like an extra 3 unfortunately.
yes the motor is being drug down to a stop. unrelated to tune because is still spinning the drivetrain weather the bolt is snug or very tight. its some load into the back of the engine or into the front of the trans
go keep it running when it happens i need about 30% throttle says the scanner, not like an extra 3 unfortunately.
10-07-2012, 10:57 AM
#5
Racer
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St. Jude Donor '13
what is the history on this, and what is the consensus?
i think i may have a problem.. well i know i do, but it only exists with the auto drivetrain hooked up.
i'm starting to think that you may HAVE to use the solid billet slip drive vs. stock spline drive/lock collar with billet driveshaft couplers... and pretty concerned it might have hurt the bottom end in some fashion.
*last night followed the stock procedure for warm up and lock down of spline drive.
today it stalled out within a couple minutes.
went under car, cracked loose spline collar and just snugged it up, idling fine??
i think i may have a problem.. well i know i do, but it only exists with the auto drivetrain hooked up.
i'm starting to think that you may HAVE to use the solid billet slip drive vs. stock spline drive/lock collar with billet driveshaft couplers... and pretty concerned it might have hurt the bottom end in some fashion.
*last night followed the stock procedure for warm up and lock down of spline drive.
today it stalled out within a couple minutes.
went under car, cracked loose spline collar and just snugged it up, idling fine??
10-07-2012, 12:08 PM
#7
You can/will damage the thrust bearing if you run it long like that.
Also, is that a crack in the splined hub? hard to tell in your picture.
Also, is that a crack in the splined hub? hard to tell in your picture.
Last edited by QuickZoh6; 10-07-2012 at 12:10 PM.
10-08-2012, 09:01 AM
#9
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Been there, done that.. The rattle of the aftermarket coupler is the next thing I want to work on eliminating though, but its a necessary evil.
10-08-2012, 09:17 AM
#10
Melting Slicks
Thread Starter
fran, were you solid all the way up to this coupler and had it locked down?
Doug after i got the car pulled down and got to drinking I may have a suggestion for that.
if i could please get a short description of what happened in each case (your particular cause/effect) did you check the end-play with engine in the car?
i guess before i put it back together need to check that
Doug after i got the car pulled down and got to drinking I may have a suggestion for that.
if i could please get a short description of what happened in each case (your particular cause/effect) did you check the end-play with engine in the car?
i guess before i put it back together need to check that
10-08-2012, 09:39 AM
#11
Melting Slicks
Thread Starter
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
10-08-2012, 01:25 PM
#12
Former Vendor
However, the torque tube its self can have some movement within.
10-08-2012, 06:14 PM
#15
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10-18-2012, 11:16 AM
#16
Melting Slicks
Thread Starter
results: TOAST
here it is documented so that hopefully others can avoid this failure
when you start taking out the flexible stock components from your c5/6 driveline, you are removing things that gm did for a reason.
a solid converter drive plate, solid front starter / drive plate, solid drive shaft couplers.. leave no room for converter thrust / drivetrain movement or expansion.
the above happened because i locked the factory spline coupler following the OEM procedure. turns out this procedure is no longer applicable (and damaging as you see) when the factory flexible components are changed out for solid. very dissapointing how one bolt and a lack of a couple sentences of proper knowledge made for such an aggravating and expensive problem. this is/was all completely avoidable.
if you choose to upgrade any of these parts, either leave the spline coupler lock collar loose (just snug enough to still spin the lock around the drive without rattling) or remove it completely as i have now seen in some pictures. OR get the one piece unit from the aftermarket. there has to be some place for the drivetrain to move so this union must float when you go to removing other flexible components.
also important to check your driveshaft for run out whenever upgrading or replacing components, since it will no longer flex the run out will go directly into your torque tube and or front coupler / crank. as seen above this can crack the spline drive if you use one, and it also gouged the converter nose bushing in my transmission. I'm also confident it exaggerated my thrust bearing problem instead of getting constant pressure it was actually taking a beating. Don't assume any of the components, stock or aftermarket, are perfect.
http://forums.corvetteforum.com/c6-t...ction-vid.html
those with experience.. is this crankshaft servicable?
here it is documented so that hopefully others can avoid this failure
when you start taking out the flexible stock components from your c5/6 driveline, you are removing things that gm did for a reason.
a solid converter drive plate, solid front starter / drive plate, solid drive shaft couplers.. leave no room for converter thrust / drivetrain movement or expansion.
the above happened because i locked the factory spline coupler following the OEM procedure. turns out this procedure is no longer applicable (and damaging as you see) when the factory flexible components are changed out for solid. very dissapointing how one bolt and a lack of a couple sentences of proper knowledge made for such an aggravating and expensive problem. this is/was all completely avoidable.
if you choose to upgrade any of these parts, either leave the spline coupler lock collar loose (just snug enough to still spin the lock around the drive without rattling) or remove it completely as i have now seen in some pictures. OR get the one piece unit from the aftermarket. there has to be some place for the drivetrain to move so this union must float when you go to removing other flexible components.
also important to check your driveshaft for run out whenever upgrading or replacing components, since it will no longer flex the run out will go directly into your torque tube and or front coupler / crank. as seen above this can crack the spline drive if you use one, and it also gouged the converter nose bushing in my transmission. I'm also confident it exaggerated my thrust bearing problem instead of getting constant pressure it was actually taking a beating. Don't assume any of the components, stock or aftermarket, are perfect.
http://forums.corvetteforum.com/c6-t...ction-vid.html
those with experience.. is this crankshaft servicable?
10-18-2012, 12:40 PM
#18
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We have seen that several times now on high HP cars with solid drive line parts and a locking/stock coupler. It still amazes me because the tq tube cannot move forward in the housing, yet it will cause that issue every time.
Get a coupler from RPM and you will be good to go.
Get a coupler from RPM and you will be good to go.
10-18-2012, 01:48 PM
#19
Le Mans Master
Mighty Mouse,
Sorry this happened to you! But I do appreciate you posting this info.... I will be doing an auto conversion next year and this is something I never thought/knew about. I'll make a point to keep the stock rubber couplers etc etc..
On a similar note, I have noticed my Scat flexplate on my BBC has gotten a little "bowed" over the years, now I can see how it happened...Probably from my converter driving foreward against it on hard launches. I added some spacers between the converter and flex plate to take up some of the slack and not have to pull the converter snout too far out of the tranny pump....Maybe I have it shimmed too tight... Been like this for 11k miles and 60 passes though so..... I'm a let it ride til something Fs up...
Sorry this happened to you! But I do appreciate you posting this info.... I will be doing an auto conversion next year and this is something I never thought/knew about. I'll make a point to keep the stock rubber couplers etc etc..
On a similar note, I have noticed my Scat flexplate on my BBC has gotten a little "bowed" over the years, now I can see how it happened...Probably from my converter driving foreward against it on hard launches. I added some spacers between the converter and flex plate to take up some of the slack and not have to pull the converter snout too far out of the tranny pump....Maybe I have it shimmed too tight... Been like this for 11k miles and 60 passes though so..... I'm a let it ride til something Fs up...
