UPDATE (4/7):
The dealer called back, today. The rep said they will be changing the whole third gear.

UPDATE (4/10):

• Dealer suggested GM if they should change the whole transmission, instead. We're waiting for their reply.
• I also asked, now that transmission is out, if we could replace the clutch without much additional labor (on my expense).I don't have issues with the clutch, but renewing it while transmission is out makes sense.

UPDATE (4/13):

• Received Singular side plates for the GTC-500 wing. These will supposedly reduce the turbulence by the end sides of the wing, making those sections more effective. When the wing becomes more effective, you can then get the same downforce with lower AOA, helping you reduce the drag.
• Looks like GM will be fixing the original transmission by replacing parts (3rd gear, etc.). I got the dealer to ask about replacement transmission, but I presume it was not approved.
• While the transmission is out, I decided to replace the clutch as well with a new unit. The dealer will charge only 1.5 hours for the clutch replacement. I am not replacing the flywheel, but also ordered a Monster clutch remote bleeder.

The side plate is considerably bigger than the original one.


They will instantly add 3 lbs of downforce AT EVERY SPEED. WIN/WIN : P
For comparison, the original side plates are cf (instead of aluminum), and weigh next to nothing.

NOTE: Their product description:
"Up to 40% increase in downforce on the outer 1/3rds of the wing – that is a 25% increase in overall downforce!
Raise your top speed! Add these endplates and reduce your wing’s angle of attack to achieve the same downforce as before with far less drag.
With the standard APR endplates, the wing is less effective near the outer sides.
These improved endplates were designed around real-world airflow and pressure data to improve the downforce and efficiency of your wing"

 

I tried a few clutch bleeders and this one is the only perfect fit I found. https://www.tickperformance.com/tick...rvette-c7-z06/ I didn't try the monster but for some reason the threads didn't match up on the others. Also when the engine blew on my 15z I had 15k miles on it. The clutch looked just like the new one so I didn't install a new clutch.I got the dealer to order a new one, and compared them side by side, but they just kept it and didn't charge. ymmv

 

Himm, perhaps I should just cancel this clutch change? I'm just doing it since it's cheap to do so at the moment..

 

I'd compare. They, or you, can look at the old clutch and see what it looks like. They may charge you the 1.5 labor anyway. On mine they had to transfer the clutch from one engine to the other so I didn't get charged.

 

To be honest, if it's damaged, it'd likely be due to the transmission/shifter issue anyway, and they would likely cover it under warranty. I was planning to do this for the regular wear, and judging from your experience, this one would likely be in pretty good shape, too, being at only 9K miles or so.

 

Mine looked new and I had over 10k track miles. The control arm bushings were toast though. front and rear

 

Anyway to tell what caused the 3rd gear issue? You think the out of alignment would really do that? I keep getting grinding when on track trying to hit 3rd exiting corners. Sometimes I just stay in 3rd which on some turns might be just as fast.

 

Cool, I replaced them already with Delrin : )) Once the car is out, I will get the AMT camber kit on it as well, and I plan to grease the surfaces of those delrin bushings with my chassis lube (Amsoil NLGI #2). They got very noisy after install, after a few rides in rain, and I fixed it temporarily by spraying WD40, but I'm sure properly lubing it would help. Finally, if LG can also ship the front splitter in the next few weeks, the car will be ready for testing.

 

I got Mark to fix me a set of monoball arms and then traded the 15 for a 19. Put the monoballs, camber kit, z07 springs, and DSC shocks on and it all works great. The monoballs are a little too harsh for the street but I don't drive on the street much anyway.

 

Sorry @djnice , I must have missed this post!

My 2 cents:
Alignment or not, what causes it is not shifting all the way in, in my opinion. We need to not rush shifts on this car, no matter how tempting it is sometimes. Every time you grind the gears, it likely means we either rushed it beyond it can handle, or even worse, perhaps our clutch timing was a wee bit off, not disengaging on time. Another important part is making sure it is fully in, which I think alignment and stock seat has a part in. Now I have race seat in the car, and I will forcefully be pushing the gear each time (instead of being too kind to it). I'm hoping this will do the trick.

I should get the car back, soon. The dealer said all the parts were shipped, last week.

 

Yeah I know what you mean. Likely rushing the shift and late on the clutch, but I did flog the spring mountain cars without that issue popping up. I haven't had it happen in the ZL1 either, but no linkage in that car.

 

I think my car was indeed misaligned as the TSB suggested, since the shifting feedback was improved after the realignment. That said, driving without that feedback for more than two years likely took its toll.

 

Is the alignment TSB the one that uses a centering tool for the neutral position when tightening the clamp or did I miss a TSB?

 

I think that's the one. 3rd gear is by neutral. Per the dealer, transmission fix is now finished, and I'll apparently wait for them to change diff fluid on Monday. The service rep also told me that one of the Granatelli toe links is cracked. I don't know what happened to it, but I 'd definitely not want to buy the very same part that failed before, so I've just placed an order for LG Motorsports' HD rear toe links. I'm guessing they are more stout anyway, and they already come with the blocking plates within the $199 price, so I think it's a good value. It's funny that after going around, I keep coming back to LG Motorsports : )

LG also stated they would ship my splitter by end of next week. If that happens, I might possibly get the car finished before the track day that will take place the following weekend; that would be nice!!

In summary:

• 1 of the rear Granatelli toe links is cracked per the dealer. I ordered a new set from LG Motorsports this time.
• LG's front splitter should be shipped end of next week.
• The transmission is now fixed, and they will hopefully release the car on Monday. I intend to drive it for a bit and change the transmission fluid again for possible break-in.
• I will definitely switch to AMT camber kit + LG's rear toe links before the next track day on May 7th, and might get the splitter on as well, if they ship it very soon.
• Oh, I will also have the Singular end plates installed, so it will likely look more serious already..

In the meantime, I'll be playing with my new DJi Air 2S drone : )

 

If you think about it take a picture of the cracked link. I got a 2s and love it!

 

Did you wind up getting a new clutch?

 

I decided to skip replacing the clutch. FYI, the dealer quoted me 1.5 hours for the clutch replacement (with tranny out), and I found the OEM clutch for $575, so it would definitely be an 'affordable' clutch replacement, if I ended up doing so : )

I think if I ever go with clutch replacement, I might try losing a bit of weight as well. It'd be nice if we had a flywheel option that's heavier than Katech's to not need tune, but still lost some significant amount of weight.

Update (4/25):
I received the new liners. Once I get the car back, I will also replace all the liners and wheel spats. With 0-degree rear caster, much less-flexible Delrin control arm bushings, and end of 335 front tire experiments, the liners will hopefully hold up longer. I'm tired of collecting rocks from under the liners : P

 

I picked up my car, and it turns out I missed it! I very much enjoyed driving it back home. Transmission/shifts feel great, and everything felt good (except rear end, which is likely out of alignment with the stock links I got them to put since Granatelli links are cracked).



Yay, they washed my car; it needed a good wash. The rear, without a wing or spoiler, looks so bland. The car actually looks more like a Stingray than a Z06 this way. I'm sure my top speed is increased, though :P


This is how the back of the conical joint looks when in good shape.


Looks like it sheared on the other side. The dealer said there was only 2 or so threads holding on to it, so they decided to ask me for replacements (I provided OEM links instead to save time).


My new LG HD links will be delivered, tomorrow. My alignment shop won't have time until next week's track event for the full alignment with camber kit (which takes at least half a day), but will install links and fix rear toe for me, to make it work for the time being.


UPDATE 4/30/2021
Decided to test out the car at the track close by on Saturday before I head out to Oregon, next week. I installed the wing back, switched to larger side plates, and also switched to Hoosiers.


I had to drill a third hole since APR's hole locations have changed in 2020, and Singular side plates use the old locations.


This one compares the new side plate to the APR's original one.


I'm keeping the wing angle low-ish, since I have not yet received LG's front splitter.



Finished.

 

Update 5/1/2021:
Tested out the car at the local track, and the car feels fine. I am no longer rushing on shifts as an extra precaution, but I'm not losing too much time due to that. I have actually improved on my personal best today, while playing around with a small formula car.

• The steering was still locking up a wee bit due to wide 11.5" front wheels. One really needs a stiffer front suspension to get to use a wheel this wide, or we'd need to try spacing it out (since it only touches on the inside). Anyhow, I'll switch to the good old 18"x11" wheels up front.
• I've also not pushed as much as I could on a few corners (like T1 by the end of straight) since I still don't have the splitter.
• Looks like things can improve if I can reduce understeer, so splitter will hopefully fix quite a few issues on this lap. My brother is also suggesting that increasing rake could also help, but I'll only get into that if the splitter can't fix things.

 

I've decided to just get the transmission rebuilt by RPM, and hopefully not worry about anything about it, anymore. We've gotten my brother's C5 Z06 transmission rebuilt when we bought the car used, almost 2 decades ago, and that transmission has held up very well at the track. GM's warranty process is taking very long (and my dealer has been pretty slow as well, I think), and looks like transmissions are on back order with no ETA. If I wait for all this, I think I'll just lose the whole season, and that would be awful : )

RPM's Level 6 rebuild does the following:
https://www.rpmtransmissions.com/page72.html
*Media blast transmission case
*Hand fit sliders and hubs
*Assembly to our specifications
*Bronze fork pads on all gears 1-6 including reverse
*Micropolish by Performance Metal
*Bronze shifter bushing when applicable
*Transmissions fitted with pump are upgraded to ZR1 pickup tube
*Carbon blocking rings

Now, here is the issue: I CAN'T FIND ANY HOW-TO on how to remove the transmission! I've found the service manual, and the transmission replacement section looks nothing but outrageous (i.e. I bet is not the fastest method), and requires spring compressor tool which you shouldn't need. I've watched videos on how it's done on C5/6 Corvettes, and I presume most of the steps will be very similar. That said, having no video or how-to on this for C7 is scary. I think I can do it, but having no friendly instructions is a bit scary.

I talked to a local shop here that's an RPM transmissions affiliate, and they can do the R&R for $2090 (16.1 hrs). The race shop I work with on alignment etc. also quoted me 16 hours but at $100/hr rate ($1600), but he doesn't want to keep my car on hoist while the transmission is out at RPM for weeks. The dealer's quote is $2200. I've talked to RPM, and they said they could do the install for much much cheaper and could finish up the tranny in a day if I can drive there, but their shop is 33 hrs of driving away(!!!). That sounds like 3 days of driving there, and another 3 days coming back, and 1-2 days of them taking care of the rebuild; I am not sure I'd want to have that much time away.

Anyway, I'm currently planning to use RPM's local installer affiliate, but man, that's so much labor!

What do you guys think? Would you do it yourself, or just let the pros take care of it? How much did you guys pay for similar work? Any place you'd trust around WA state?

I keep thinking about just starting to remove it, but then I think about what would happen if I break something, and how much it would extend the timeline in the middle of the season. Needless to say, not happy at all with our local labor prices : )