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Discussion Starter · #1 ·
Well I went back to the track today without the donaldson-I ran my stock modified airbox with a fram CA3914 filter and get this I ran [email protected], [email protected], [email protected], [email protected] I made a total of 25 passes and everyone was a 12.50 or better. My very first pass was a [email protected] Then something weird happened on my last pass my tranny would not come out of 4th. I let it cool down a bit and still only 4th. So i head home driving in 4th at 60mph then try to shift into 5th-it worked, all of a sudden all gears worked until i come to a stop. At this point the car only goes into the gear that it was last in. I thought these trannies were tough-what could of happened?
 

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Wow, those are some sweet numbers!


It sounds like you may have chewed some syncros. The broken pieces in the tranny can cause further damage :(
 

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I believe I've heard this story before

vortech, great runs but sorry to hear about your trans!!! :(

I think I have a link for you though, check this out:

http://64.225.48.150/chspeedfreaks/c5_t56break01.html

"The shifter was hard as a rock and felt like it was stuck in 4th. With some forceful coaxing I was able to find neutral then 3rd then 4th before realizing something was terribly wrong and just getting home would be a good thing...."

Maybe you bent the same tab this guy did... man does that suck. Hope the general fixes her right for you.

I did six passes today, pulling 12.57 as my best. You were smokin' while the trans lasted! :D

After hearing your story, I don't think there is going to be any powershifting for me, I'll live with my 12.57...
 

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What kind of MPH were you running w/ the Donaldson, and did you cut the shroud?
 

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Discussion Starter · #5 ·
donaldson

my best run with the donaldson was [email protected] with a 2.047 sixty foot. Stock box cut out be me [email protected] with a 2.003. Go figure the stock stuff really does work-apparently the donaldson was causing too much turbulance at the mouth of the meter causing incorrect readings. The 02's have no screen so perhaps if the screen was there it would of made a difference. I personaly think that the injectors on these cars need to be bigger to compensate for any additional airflow. I might be testing a sidewinder soon to see if it can better my 12.314. I cannot beleive the tranny broke-that's a real pisser-i never even powershifted the car-I always lifted cause powershifting caused me to hit the rev limter.
 

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Re: donaldson

Interesting stuff regarding the donaldson... I run one on my car, but have yet to run it in the 1/4(waiting for cooler air here in FL). I believe you have(by the sounds of it) some clutch related issues there. I could be mistaken, but if it were gearbox, loud crunching noises would most likely be heard, immediately turning your stomach in knots--good luck!!!

George
 

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Vortech, great runs, sucks about the tranny. :( I guess you did not get a warning re tranny overheating?
 

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Re: I believe I've heard this story before

pmontelo said:
I think I have a link for you though, check this out:

http://64.225.48.150/chspeedfreaks/c5_t56break01.html

"The shifter was hard as a rock and felt like it was stuck in 4th. With some forceful coaxing I was able to find neutral then 3rd then 4th before realizing something was terribly wrong and just getting home would be a good thing...."
That link is from my site.

Unfortunately I think you've done the same thing I did to my M6. I don't think your linkage is to blame. The reason I say this is because I had to replace my linkage right after MTI repaired the tranny (it fell apart while cruising?!? The POS is held together by some really weak pins) and when I dragrace I beat the hell out of the tranny and the linkage wasn't bent at all upon inspection/comparison with the new unit. Also, there have been 2 '01 Zs I know of that have had the same thing happen from powershifting.

I really think your problem is internal...sorry.

Hopefully you can find a good dealer and have them replace it for ya...good Luck.

Thanks
 

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When you say weak pins, I *think* I know what you mean but I'm not certain.

Transmission linkages are often held together with 'rolled pins' or 'roll pins'.

*REAL* roll pins are just that - they are metal rolled many times to form an expansion pin. They are very strong. The core is almost solid spiral metal.

However, 98% of what you see available is just pretending to be a real rolled pin. The commonly available pins are just metal shaped in the form of a C. Those are more prone to shearing.

I do my own trans work on my toploaders (though probably not for a trans that has a warranty). I use real roll pins in the shift linkage. I do that to prevent fatigue failure during one of those 1400 shift road course days, not because I am a hard shifter.

But if I were the one underwriting the warranty on your street trans, I might use the C pins. Why? So you break the pins before you break the gears. Or, so I could see abuse by the wear on the pins.

Now if I put my business hat on and pretend I'm building transmissions to feed my family.. A customer who bends their Ripper and damages the trans is not going to get warranty coverage on a street trans. I do not see how you can bend a ripper and not call it abuse.

If you want a bullet proof racing trans, I suggest you go that route and get one. But don't expect it to have syncros, because they usually don't. Some shops will re-machine your syncros for faster shifting, but that is a bit of a kludge.

Liberty's Transmissions in Taylor Michigan can do this. For quite some time they were building Bob Glidden's drag transmissions (maybe they still do, for his son). The real racing transmissions, of course, have dog-gears instead of syncros.

But generally, you can't have everything. A bullet-proof drag trans is going to be a bear to drive on the street. I'm not aware of any exceptions to that.

Me, in my opinion power shifting a trans and expecting warranty coverage is abusing the system. A few powershifts, okay.. But a bunch??

I wonder how many would do it if they were on the hook for the repair bills? If you say you would, great - then pay the bill and don't ask everyone else who buys a Z06 to cover the cost of your transmission consumption.

Or maybe I'm just getting too conservative and righteous since turning 30. Maybe I've rebuilt too many transmissions and the thought of someone else fixing my trans for free is just too good to be true.

This is my first new Corvette.. Maybe an owner benefit of buying a new Z *is* to drive it really hard and let the General sort it out??? If that's the consensus, then I will get in line and proudly salute the General! :lol:
 

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BrianK said:
When you say weak pins, I *think* I know what you mean but I'm not certain.

Transmission linkages are often held together with 'rolled pins' or 'roll pins'.

*REAL* roll pins are just that - they are metal rolled many times to form an expansion pin. They are very strong. The core is almost solid spiral metal.
I agree. The pins themselves are very strong as far as material but the expansion design that they have won't hold up to any real use imo, the linkage material is a lot softer and the groove/collar is soo small. When my linkage came out it was in pieces and I can easily slip the pin that failed in and out of it's slot without any tools. Because of this, when mine failed, I had no shifting ability at all...the shifter just floated around in the boot...I had to limp home in 4th gear.

I'll try and post some pics of my old linkage for everyone to see. Hopefully they will help out my poor verbal explanation. I know you have a lot more experience and appreciate your opinion.

BTW, I was happy to tweak the synchro instead of shattering the gears like I have done with other manuals in the past. I think this is the weak link in the system instead of the linkgage. Either way you have to rip the rear half of the car off to replace/rebuild any of it and that sucks. :(

I think that receiving warranty work for a few powershifts is ok vs. beating the hell out of it, too.

I also think that the M12 is a weaker unit than the M6 because the ones that have failed around me did so under a lot less abuse. Hopefully, Im wrong.
 

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Discussion Starter · #15 ·
No Powershifting!

Okay lets get some things clear-I never powershifted the car at the track-I only once tried it on the street but hit the rev limiter due to excessive wheelspin. Now let's talk powershifting-to my knowledge that meant never lifting the gas pedal while shifting-right? Well I always lifted when shifting to get these #'s. How the ripper bent is beyond me-maybe some faulty or undergraded steel. One thing for sure is that once I put the stock shifter back in which is straight the car shifts fine except in 3rd and 4th were it grinds a bit. I think this could be due to bent fork or some misaligned linkage which is in turn due to the b&m being bent. The t56 is very strong-I've seen guys go 10's with them without a problem-it is the best compromise of a street-strip tranny. I had a Liberty 5-speed in my 8 sec stang and yes Billy Glidden still uses one in his mustang-that's why I bought one. They are awesome but guess what-I broke 1 every 4 passes. I know i drive the car hard-but like I said i never powershifted it and blame the bent ripper for the damage. I'll find out on thursday what the dealer finds.
 

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Wow! :eek: I can't believe that you bent your Ripper. I mean I believe you but mine is still straight and people have told me that it looks like I'm trying to bend it.

Your symptoms sound just like mine before the tranny decided enough was enough. It started to grind between 3rd and 4th while racing then started doing it will granny shifting as well. I was willing to live with it but after a couple months the synchro system became too damaged.

No powershifting? You really deserve a brand new out of the box tranny replaced under warranty.
 

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How the ripper bent is beyond me-maybe some faulty or undergraded steel.
I assume they heat treat the shifter. It could be bad heat treat.

I once bought a stud girdle from Probe Industries. It came with new rocker nuts that were longer.. Switching all of the nuts and putting it on takes quite a bit of time. After I made the switch, I kept losing valve lash on my solid roller valve train. I'd never lost lash before. I was constantly chasing lash. Off came the girdle!

A month later, I tried it again. Same thing - lost lash. Off it came. I called Probe. Turns out the nuts were junk - bad heat treat. Sure enough, I could scribe the soft junk ones with a good one.

They sent me a set of Crane nuts free of charge (guess making the girdle out of aluminum is easy compared to making the nuts). I never put the girdle back on and have since sold those heads. I curse whenever I see that girdle in the garage.
 

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Okay lets get some things clear-I never powershifted the car at the track-I only once tried it on the street but hit the rev limiter due to excessive wheelspin.
Just to be clear, I wasn't implying that *you* had (especially since you'd already said you weren't).

I just wanted to frame the questions about warranty coverage around guys who are powershifting.
 

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Discussion Starter · #19 ·
synchros

I don't think the syncros are gone-the tranny never grinded until after my last pass when the car was stuck in 4th. Hell I've only had the car for month and have been to treack only 3 times yet. I hope they can fix it before the 10/20/01 as I'm going back to the track with the new Halltech T-1 airfilter and my own cold air setup I'm going to try.
 

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Powershifting or Hardshifting?

I've heard various people define "Powershifting" in different ways.

The "no-lift-to-shift" part has always alluded me... If you don't lift, you *will* hit the rev-limiter, no doubt about it. I think, ideally you just want to re-apply full throttle at the same time you release the clutch (but then I've only run a 12.57 so far :lol: ). The RPMs have to drop back to 4400 in most of the gears after a rev limit shift anyway. I would think keeping the engine at 6600 while releasing the clutch will only help to break the tires loose.

I think the part of "Powershifting" that concerns me most (where the real tranny damage is going to occur) comes from a quick stab of the clutch and the hard-as-hell pull or push of the shifter.

When I drag race I do try to shift as quickly as possible, but without forcing the shifter into the gear. I think forcing the shifter on a 2-3 upshift could definately bend the shifter if you missed the gate.
 
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