That's exactly why I don't even want to bother. My car is practically brand new, and shifts absolutely perfect after a mile at the most. Why the hell would I allow a dealer to mess with my new transmission, if it can be exactly the same as before? And that's the best case scenario. Chances is they'd screw something up. I honestly don't think shifting at 15 mph with the clutch depressed is really going to screw anything inside. If it does, then it's a POS. But I'll shift at 6 mph from now on, which will put 2nd at idle speed. That way I don't have to slip my clutch starting in 2nd. Or rev the engine higher when cold to skip 2nd. I drive 5K miles a year, and most of that on trips, so my tranny should last a long time, even if it keeps crunching. I'll keep experimenting and see how it can be minimized, like shifting even slower, or quicker. Blipping the throttle with the clutch depressed doesn't do anything for the shift itself. For that we'd have to double-clutch, and blip the throttle when the clutch pedal is out, and get the rpm exactly right.

For those with older Z51s, I'd do what Rick suggested. In fact, I wouldn't touch my '12 GS tranny without upgrading to those gears. Hey Rick, you never answered the question why GM supposedly put those stupid weird gears in the MZ6 tranny. There must be a reason, even if it's a stupid one.

Finally, I haven't heard anybody damaging his tranny with this cold crunching, which is a good sign, I guess. Hopefully GSFlyer will start a poll to see how many have the issue, especially with new cars. With my stupid luck, it's always something. Got 2 piston-slapping engines (LS1 and LS2), and now that I finally got a quiet engine, now this . It's always something. Oh well. At least it's not a big issue. If it continues, would just get rid of the car in a few years, and never go back to GM. If they can't get a f***ing car right after 8 years of production (especially something that has been a problem for a while), I'm done with them. And the issue is it's not a problem now, but can be a problem later. Since the tranny is absolutely perfect when warm, I'd be stupid letting a dealer mess with it now, so won't. Until I have difficulty shifting to 2nd, or it jumps out of gear, or something that actually affect drivability (if ever), then it'd be time to do something about it. And that's probably not going to happen to me at 5K miles per year. Have a good one folks.

 

There isn't any GM TSB's I know of but when TR6060 owners complained about the 2nd gear issue, Tremec started using carbon blockers for 2nd gear only. Figure that one out.

I wouldn't worry about it and enjoy the car after warmed up. I think the problem is the main shaft preload that changes after it's up to temperature.

 

Hey Rick, thanks again for chiming in. That makes more sense, since I seem to be one of only a few who have the issue, so it has to be something different than the freaking crooked-teeth gears alone. A couple of new questions:

- Do you think that eventually goes away or not?
- Is it considered a manufacturing defect?
- Why only second? The main shaft would affect ALL gears, no?

I don't want to touch my new car, at least for now. But if I ever do, I want a NEW tranny, not a local mechanic who has never done tranny work attempting to fix it. Now that it's obvious it's not the 2nd gear itself (most other trannies don't crunch), a new tranny could solve the issue; at least statistically (all bad engines and trannies always seem to find me ). But somehow, I don't think I'd ever get one even if I ask for one. A rebuilt one would be the best case scenario, if at all IMO. And for all I know, it could be just like the one I have now.

Anyway, I have bad news. Drove the car today, and stupid 2nd kept crunching well after 2 miles this time. This is my first winter with my car, and it finally started to get cold here. The high today was only 58, and it's only going to get worse as winter sets in. As a result, tranny is going to take longer and longer to heat up. I'll probably start just skipping 2nd altogether until 3 miles or so, just to be safe. But it SUCKS big time. That's why I bought this 'old' car, to avoid issues, especially mechanical ones. It's a major job, and small shops here that rarely work on Vettes are prone to screw something up. I've seen it a ton of times with other cars owned by me and friends. It's not nearly as bad as an engine removal, but a lot of crap still has to be removed.

And no, Amsoil fluid didn't make an iota of difference on this issue. Once fully hot, tranny shifts like a dream. What a pleasure to drive this car. A damn shame something always has to sour my ownership experience. Oh well. Will put up with 1-3 shifts when cold, and sell the damn thing before warranty expires.... unless it eventually goes away. Hard to know without knowing what the hell is going on in there for sure. Thanks again for all your help.

 

You are not the only one with this issue. Other members/owners have this issue when cold but some do and some don't.

-I have not experienced first hand this problem going away with time so I cannot comment.
-I have seen brand new units from GM/Tremec with the input shaft loose (spec calls for .002" preload on the main shaft) so take it for what it's worth regarding the quality control from Tremec.
-I cannot answer that question but given enough time and money, I'm sure I can figure it out.

 

Folks, does anybody have a contact number for Tremec? I'd like to have a word with them about my issue, to hear what they think. This crunching should have been fixed by now.

Talked to the closest dealer to my house, and SA said he doubts GM would authorize a new tranny. As expected. If that's his answer after I take my car and drive a tech around so he can confirm my cold 1-2 shift grinding, I'd probably just get rid of it. If GM accepts, I'd try to drive the car often, and shift A LOT when cold, so the grinding either goes away (wishful thinking ) or it messes 2nd permanently. At that point it'd be obvious tranny has to come out. But I'm almost sure dealer will mess something, like I've read in many, many cases, from vibrations that cannot be found, to recurrent alignment issues, to misaligned shifter rods. And the sad part is I could get another POS transmission, just like I did with my new car (only driven by dealer personnel, with 9 miles on the clock when I got it delivered). But at least I'd give it a try knowing I'd get a new tranny, and hopefully this dealer could prove me wrong. If any of that happens, I'd get rid of the car too. I don't have the stomach for that kind of crap. Plus the other almost given side effect is scratches, scuffs, stains... you name it. And yes, that's personal experience, not speculation. That's why I bought this 8-yr-old freaking car, to avoid crap like this. I can live with cosmetic stuff, which I usually fix myself. But major crap like this completely ruins the ownership experience for me. Rather drive a sporty Hyundai Genesis Coupe V6 or 370Z than a V8 POS. On my last 4 expensive cars I had engine problems with 3, and now the transmission. Just can't catch a break . But am not going to give up trying to keep it. With so many issues with '12 and '13 Vettes, I feel for those who will buy the first C7s. I'm done with GM, regardless of what happens with this car. Have a good one folks, and sorry for the rant .