C7 Tech/Performance Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

M7 grinding 1st to 2nd shift

Thread Tools
 
Search this Thread
 
Old 12-01-2016, 12:31 PM
  #1  
Cchief
Advanced
Thread Starter
 
Cchief's Avatar
 
Member Since: Aug 2016
Location: Southern NJ
Posts: 95
Received 7 Likes on 5 Posts
Default M7 grinding 1st to 2nd shift

I know this has been discussed in the past but my 2016 Z51 Stingray goes back for the second time next week to the dealer for a "fix".
I am looking for someone who had this issue that could tell me how they fixed it.
It does shift somewhat better when it warms up or the rev match is on but the grinding is not acceptable. The car has 750 miles on it.
Old 12-01-2016, 01:44 PM
  #2  
Bill Dearborn
Tech Contributor
 
Bill Dearborn's Avatar
 
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
Posts: 40,096
Received 8,930 Likes on 5,334 Posts

Default

Originally Posted by Cchief
I know this has been discussed in the past but my 2016 Z51 Stingray goes back for the second time next week to the dealer for a "fix".
I am looking for someone who had this issue that could tell me how they fixed it.
It does shift somewhat better when it warms up or the rev match is on but the grinding is not acceptable. The car has 750 miles on it.
Are you saying it is grinding on the 1-2 shift after the transmission fluid is warm? Every Tremec transmission I have had in two C5s, one C6 and now the C7 has nibbled a little on the 1-2 shift when the fluid was cold. That always disappeared by the time I had driven 1 or 2 miles even if it was 20 degrees or lower outside.

If you are getting grinding or nibbling after warm up you may not be depressing the clutch all the way or may be letting it out too soon.

If that isn't the case then something may be wrong inside the transmission or with the shifting linkage running alongside the transmission.

Has the mechanic working on the issue taken it for a drive with you in the car? If not then that is the first thing that needs to be done. This kind of thing can't be communicated by a short note written on the RO. The conditions you are describing have to be demonstrated by you and then experienced by the guy who will do the repair. Other than that you will get a NTF report.

My 97 was giving me fits when I was hitting reverse Vs fifth gear and after I took the mechanic for a ride he ordered a part but when it came time to replace the part he noticed there was nothing different between the new and old parts. He did some research and called me telling me I had to change the way I was shifting. The solenoid lock out had an over ride that permits the car to be put in reverse if there is a problem with the solenoid. I was shifting with too much force and getting into the over ride. Once I changed my shift habit I never had the problem again over the following 5 years I had the car.

Bill
The following users liked this post:
Cchief (12-01-2016)
Old 12-01-2016, 02:12 PM
  #3  
Cchief
Advanced
Thread Starter
 
Cchief's Avatar
 
Member Since: Aug 2016
Location: Southern NJ
Posts: 95
Received 7 Likes on 5 Posts
Default

Originally Posted by Bill Dearborn
Are you saying it is grinding on the 1-2 shift after the transmission fluid is warm? Every Tremec transmission I have had in two C5s, one C6 and now the C7 has nibbled a little on the 1-2 shift when the fluid was cold. That always disappeared by the time I had driven 1 or 2 miles even if it was 20 degrees or lower outside.

If you are getting grinding or nibbling after warm up you may not be depressing the clutch all the way or may be letting it out too soon.

If that isn't the case then something may be wrong inside the transmission or with the shifting linkage running alongside the transmission.

Has the mechanic working on the issue taken it for a drive with you in the car? If not then that is the first thing that needs to be done. This kind of thing can't be communicated by a short note written on the RO. The conditions you are describing have to be demonstrated by you and then experienced by the guy who will do the repair. Other than that you will get a NTF report.

My 97 was giving me fits when I was hitting reverse Vs fifth gear and after I took the mechanic for a ride he ordered a part but when it came time to replace the part he noticed there was nothing different between the new and old parts. He did some research and called me telling me I had to change the way I was shifting. The solenoid lock out had an over ride that permits the car to be put in reverse if there is a problem with the solenoid. I was shifting with too much force and getting into the over ride. Once I changed my shift habit I never had the problem again over the following 5 years I had the car.

Bill
Bill, thanks for the reply, I have even tried moving the seat in different ways to make sure the clutch was fully depressed. I have been driving manuals for over 50 years and have never experienced this type of grinding, even when it warms up. Gears 3-7 shift fine.
Old 12-02-2016, 06:42 AM
  #4  
spearfish25
Melting Slicks
 
spearfish25's Avatar
 
Member Since: Apr 2016
Location: Naples FL
Posts: 3,085
Received 727 Likes on 479 Posts
Default

Mine does it cold for the first 1/2 mile. A double clutch for the 1-2 up shift solves the problem. My CTSV did it as well and Redline fluid completely resolved it. I'm just reluctant to dump Redline into the Z06.
Old 12-05-2016, 05:24 PM
  #5  
Cchief
Advanced
Thread Starter
 
Cchief's Avatar
 
Member Since: Aug 2016
Location: Southern NJ
Posts: 95
Received 7 Likes on 5 Posts
Default

Originally Posted by Bill Dearborn
Are you saying it is grinding on the 1-2 shift after the transmission fluid is warm? Every Tremec transmission I have had in two C5s, one C6 and now the C7 has nibbled a little on the 1-2 shift when the fluid was cold. That always disappeared by the time I had driven 1 or 2 miles even if it was 20 degrees or lower outside.

If you are getting grinding or nibbling after warm up you may not be depressing the clutch all the way or may be letting it out too soon.

If that isn't the case then something may be wrong inside the transmission or with the shifting linkage running alongside the transmission.

Has the mechanic working on the issue taken it for a drive with you in the car? If not then that is the first thing that needs to be done. This kind of thing can't be communicated by a short note written on the RO. The conditions you are describing have to be demonstrated by you and then experienced by the guy who will do the repair. Other than that you will get a NTF report.

My 97 was giving me fits when I was hitting reverse Vs fifth gear and after I took the mechanic for a ride he ordered a part but when it came time to replace the part he noticed there was nothing different between the new and old parts. He did some research and called me telling me I had to change the way I was shifting. The solenoid lock out had an over ride that permits the car to be put in reverse if there is a problem with the solenoid. I was shifting with too much force and getting into the over ride. Once I changed my shift habit I never had the problem again over the following 5 years I had the car.

Bill
Took it to the dealer today, they told me it is a known issue that GM is trying to find a fix, called GM, they basically told me the dealer is blowing smoke up my butt.
Old 12-06-2016, 05:59 AM
  #6  
smonska
Racer
 
smonska's Avatar
 
Member Since: Mar 2002
Location: Northampton MA
Posts: 284
Received 2 Likes on 2 Posts

Default

Try changing the fluid to Amsoil TorqueDrive. Worked great in the TR6060 in my C6. The Dexron VI they put in these today is really too thin to be a great manual trans fluid. It's substantially thinner than the Dexron III the trans synchros were designed with back when they were the T56.

Last edited by smonska; 12-06-2016 at 06:02 AM.
Old 12-06-2016, 09:18 AM
  #7  
Doctor Mark
Racer
 
Doctor Mark's Avatar
 
Member Since: Dec 2005
Posts: 341
Received 273 Likes on 118 Posts

Default

My shifting improved with Redline ATF D4. The fluid in the box is a Dextron 3 varient not Dextron 6 which is in the AT.
That being said, you can not rush the shifts especially when cold. Mine has gotten better with additional miles. Frequently go first to third until fluid is warmer.
Old 12-07-2016, 10:05 AM
  #8  
Bill Dearborn
Tech Contributor
 
Bill Dearborn's Avatar
 
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
Posts: 40,096
Received 8,930 Likes on 5,334 Posts

Default

Originally Posted by Cchief
Took it to the dealer today, they told me it is a known issue that GM is trying to find a fix, called GM, they basically told me the dealer is blowing smoke up my butt.
Who in GM did you talk to? If it was Customer Service they are mushrooms when it comes to knowing what engineering is working on. The problem is any solution has to involve Tremec since they designed and build the transmission.

Bill
Old 12-07-2016, 10:39 AM
  #9  
Cchief
Advanced
Thread Starter
 
Cchief's Avatar
 
Member Since: Aug 2016
Location: Southern NJ
Posts: 95
Received 7 Likes on 5 Posts
Default

Originally Posted by Bill Dearborn
Who in GM did you talk to? If it was Customer Service they are mushrooms when it comes to knowing what engineering is working on. The problem is any solution has to involve Tremec since they designed and build the transmission.

Bill
Bill, i did speak with customer service but haven't received an answer, However, yesterday i reached out to Tremec directly and to American Powertrain who is the largest Tremec dealer in the US. Also had someone contact the Corvette brand manager at the corvette plant quality control. Hopefully one of the three will get back to me with an informative answer.
Stay tuned!
Len
Old 12-09-2016, 02:30 PM
  #10  
0Anthony @ LGMotorsports
Former Vendor
 
Anthony @ LGMotorsports's Avatar
 
Member Since: Aug 2005
Location: Lewisville TX
Posts: 16,898
Received 406 Likes on 300 Posts
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13


Default

I'm going to agree with Bill on this one too.. Every T56/TR6060 box I have driven has a slight click/grind going 1-2 shift until they are up to temp. Now if it is a heavy grind then I'm going to say something else is wrong and get it fixed under warranty.

RedLine D4 helped but it still had to get up to temp to shift right.
The following users liked this post:
Cchief (12-09-2016)
Old 12-09-2016, 03:34 PM
  #11  
Cchief
Advanced
Thread Starter
 
Cchief's Avatar
 
Member Since: Aug 2016
Location: Southern NJ
Posts: 95
Received 7 Likes on 5 Posts
Default

Originally Posted by Anthony @ LGMotorsports
I'm going to agree with Bill on this one too.. Every T56/TR6060 box I have driven has a slight click/grind going 1-2 shift until they are up to temp. Now if it is a heavy grind then I'm going to say something else is wrong and get it fixed under warranty.

RedLine D4 helped but it still had to get up to temp to shift right.
The saga continues, today I received a call from GM customer service telling me the dealer service manager and tech person wanted to drive it next week and go from there.
Also, yesterday spoke with Termac, they told me they pass on inquiries such as mine up to their contact at GM, so I should be expecting a call from them Independant of their customer service.
They implied it was a great transmission and I shouldn't have any issues, they really don't entertain inquiries directly from GM customers.
Old 12-10-2016, 04:09 PM
  #12  
TBEVO
Intermediate
 
TBEVO's Avatar
 
Member Since: Apr 2016
Posts: 36
Received 3 Likes on 3 Posts
Default

My 2016 seems to grind a bit as well going from first to second even when warm. Its annoying.
The following users liked this post:
Cchief (12-10-2016)
Old 12-10-2016, 07:10 PM
  #13  
black_c7
Burning Brakes
 
black_c7's Avatar
 
Member Since: Nov 2015
Location: Kuwait
Posts: 1,133
Received 36 Likes on 34 Posts
Default

i had this issue with my 2015, mine always grind if I'm shifting 1st to 2nd under 2500 rpm, when i shift above 2500 it doesn't grind, i proved that and they changed the whole transmission for me
Old 12-10-2016, 08:25 PM
  #14  
PLRX
Team Owner

 
PLRX's Avatar
 
Member Since: Aug 2005
Location: Riverside County Southern California
Posts: 34,988
Received 501 Likes on 342 Posts
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20


Default

Mine does it, took it to the dealer, and the shifter was aligned. It still do it when it's cold.
Old 12-10-2016, 10:47 PM
  #15  
cvp33
Melting Slicks
 
cvp33's Avatar
 
Member Since: Sep 2005
Location: RACE TRACK USA
Posts: 2,770
Received 1,050 Likes on 660 Posts

Default

Same here, seems to be a cold/pre-operating temp issue.
Old 12-11-2016, 09:44 AM
  #16  
Hawkbarr
Racer
 
Hawkbarr's Avatar
 
Member Since: Sep 2016
Posts: 352
Received 220 Likes on 126 Posts
Default

FWIW, Ford has this same issue with the Shelby GT500 transmissions from Tremec since 2007. No real fix identified, despite owners trying different lubricants, double clutching, changing shifters, etc. Those steps seem to help but don't 100% eliminate the issue. Plus the problem doesn't happen to everyone either. I've been lucky on my GT500's and two C7s with M7s. I make sure to warm up the tranny fluid(we all have tran. temp guages) and make sure the clutch is 100% depressed.
No real value add here, but just some perspective on the Tremecs.

Get notified of new replies

To M7 grinding 1st to 2nd shift




Quick Reply: M7 grinding 1st to 2nd shift



All times are GMT -4. The time now is 10:54 PM.