Trouble shifting from 1st to 2nd

[macpac91]

I have a '06 z51. When accelerating hard (say 3000rpm or higher) I can't get a clean shift into second gear it either grinds or 'hits hard' - not smooth. All the other gears shift smoothly under hard acceleration. I changed all oils (accept for the differential) this week. Also had the clutch fluid replaced.

Any ideas? Is this normal in anyway?

 

[KANE]

I have a '06 z51. When accelerating hard (say 3000rpm or higher) I can't get a clean shift into second gear it either grinds or 'hits hard' - not smooth. All the other gears shift smoothly under hard acceleration. I changed all oils (accept for the differential) this week. Also had the clutch fluid replaced.

Any ideas? Is this normal in anyway?

Grinding isn't normal. What is your driving style? Sounds like a bad synchro if it is only one gear. Which, is entirely possible since most folks don't shift hard into first- hard shifting comes to 2, 3, and 4 as folks accelerate.

 

[macpac91]

Grinding isn't normal. What is your driving style? Sounds like a bad synchro if it is only one gear. Which, is entirely possible since most folks don't shift hard into first- hard shifting comes to 2, 3, and 4 as folks accelerate.

Thanks. I don't consider my style to harsh, but I do like to launch it a handful of times each month. I've put about 3.5k on it since I purchased it in October. I've never taken it to the track or strip, but was considering it now I'm having second thoughts. I'll have the dealer look check it out.

 

[Hib Halverson]

When you changed the clutch fluid, did you bleed the system per the Service Manual?

I ask that because sometimes, "hard shifting" problems can be clutch- rather than transmisison-related.

I also must ask about shift technique. I sometimes find that complaints of a missed or high-effor 1-2 shift when trying to shift quickly are "operator problems" relating to improper coordination of clutch action and shifter movement during a quick shift. I sometimes find that people tend to move the shifter into 2nd just a hair too soon or they are too slow in getting the clutch on the floor. Either of those will cause a missed or "hard" 1-2 shift.

If there's no problem with clutch and no trouble with shift technique, then the trans is probably at fault.

You mentioned you changed the lube...what kind of lubricant did you put in it?

 

[macpac91]

Thanks. The dealership just informed me its a bad synchro - covered under warranty.

 

[KANE]

Grinding isn't normal. What is your driving style? Sounds like a bad synchro if it is only one gear. Which, is entirely possible since most folks don't shift hard into first- hard shifting comes to 2, 3, and 4 as folks accelerate.

Thanks. The dealership just informed me its a bad synchro - covered under warranty.

Glad to hear GM will cover it. Seemed really premature for a synchro... but sounded like one (based on your description) for sure.

 

[Vette_06]

Same car and issue?

I have the same car and have almost the same issue, I am having the 1st gear lock out issue. Hard to shift into 1st at lights or downshifting. My dealer said they need to take aprt transmission to replace the first gear or syncro. I am not very happy about it. I have very low miles and too many problems so far.:confused
This issue turned out to be a broken snap-ring inside the transmission holding the 1st gear assembly in place on the shaft, it tore it all up.

Perfect?

Glad to hear GM will cover it. Seemed really premature for a synchro... but sounded like one (based on your description) for sure.