1995 ZR1 Transmission Really Stiff...Sometimes - ZR-1 Net Registry Forums

RichieDMD · 08-09-2022

I have had my ZR1 for about a year now and I drive it occasionally. I have noticed that some days the transmission is super stiff. It seems to be more in the morning when I'm leaving the house and on my way to work so I just chalked it up to being cold. I don't live far from work so I don't think it even fully warms up in the morning.

But some days it's worse than others. Planning on driving the car this week I have left it out over night. Yesterday I drove it and it was a little hard shifting in the morning (I find that on the way to work I often get a little grind noise going into 3rd). But this morning it was even worse. It was so stiff I couldn't even get it into reverse to back it out of the driveway. Using both hands I couldn't seem to get it in gear. After a minute or two of struggling with it I put it back into first and shut it off...I drove my 2002 Camaro to work instead. It was a little hard to get it back into first but not bad.

I understand that high performance cars from this era tend to have challenging transmissions when cold...but it seems some days this is more than that. Any thoughts?

Car has 38K miles on it.

Thanks.

DRM500RUBYZR-1 · 08-09-2022

Something is amiss.
It should not be anywhere near as difficult as oyu have described.

Two suggestions.

First take it to a shop that will drain and refill the transmission with the correct lubricant. Mobil 1 or Amsoil are considered to be ideal for the ZF trans.

Second, make sure that your clutch fluid is both clean and more importantly full.

Once both of those have been done, if your effort is not greatly reduced then the transmission may have a mechanical issue.

That eliminates the simple easily correctable causes.
Good luck and keep us posted of your progress.

Marty

WARP TEN · 08-09-2022

Quote:

Originally Posted by RichieDMD

I have had my ZR1 for about a year now and I drive it occasionally. I have noticed that some days the transmission is super stiff. It seems to be more in the morning when I'm leaving the house and on my way to work so I just chalked it up to being cold. I don't live far from work so I don't think it even fully warms up in the morning.....

Boy that sounds a lot like me when I get up in the morning! --Bob

RichieDMD · 08-09-2022

Quote:

Originally Posted by DRM500RUBYZR-1

Something is amiss.
It should not be anywhere near as difficult as oyu have described.

Two suggestions.

First take it to a shop that will drain and refill the transmission with the correct lubricant. Mobil 1 or Amsoil are considered to be ideal for the ZF trans.

Second, make sure that your clutch fluid is both clean and more importantly full.

Once both of those have been done, if your effort is not greatly reduced then the transmission may have a mechanical issue.

That eliminates the simple easily correctable causes.
Good luck and keep us posted of your progress.

Marty

The fluid recommendations here call for a Castrol 10/60. Before I call around I want to make sure I'm verifying the proper oil. What should I tell them?

https://www.zr1netregistry.com/Infor...endations.aspx

DRM500RUBYZR-1 · 08-09-2022

The Castrol is fine as well!

Marty

viper107 · 08-09-2022

car should shift like butter,do not force the shifter! its either got a tired clutch or a internal worn part or parts if the fluid change doesnt fix it

lfalzarano · 08-09-2022

Check your clutch fluid level under the ECM. If the transmission fluid hasn?t been changed, get it done.

Sent from my iPhone using ZR-1 Net Registry

RichieDMD · 08-09-2022

Thanks for the advice everyone. I will get the fluid done ASAP.

RichieDMD · 08-09-2022

So I called around to a few shops today to find a place to go (everyone is super busy right now). One of the people I spoke with asked me if I had a hard time putting it in reverse when the car was shut off. I admitted I hadn't tried.

When I got home today I decided to move cars around and put the ZR-1 back in the garage for now as I won't be driving it the rest of the week. Before starting it, I tried to put it into reverse and it was easy. I then moved it back to first gear, started the car, and tried to go into reverse. I was able to get it into gear but it was much more difficult.

The person I spoke with must have had a reason for asking me this...but I'm not overly knowledgeable with transmissions. What would this indicate (if anything)?

secondchance · 08-09-2022

Quote:

Originally Posted by RichieDMD

So I called around to a few shops today to find a place to go (everyone is super busy right now). One of the people I spoke with asked me if I had a hard time putting it in reverse when the car was shut off. I admitted I hadn't tried.

When I got home today I decided to move cars around and put the ZR-1 back in the garage for now as I won't be driving it the rest of the week. Before starting it, I tried to put it into reverse and it was easy. I then moved it back to first gear, started the car, and tried to go into reverse. I was able to get it into gear but it was much more difficult.

The person I spoke with must have had a reason for asking me this...but I'm not overly knowledgeable with transmissions. What would this indicate (if anything)?

Possibly, clutch not disengaging completely.

08-09-2022	#1
RichieDMD Join Date: Feb 2020 Location: Oregon Posts: 67	1995 ZR1 Transmission Really Stiff...Sometimes I have had my ZR1 for about a year now and I drive it occasionally. I have noticed that some days the transmission is super stiff. It seems to be more in the morning when I'm leaving the house and on my way to work so I just chalked it up to being cold. I don't live far from work so I don't think it even fully warms up in the morning. But some days it's worse than others. Planning on driving the car this week I have left it out over night. Yesterday I drove it and it was a little hard shifting in the morning (I find that on the way to work I often get a little grind noise going into 3rd). But this morning it was even worse. It was so stiff I couldn't even get it into reverse to back it out of the driveway. Using both hands I couldn't seem to get it in gear. After a minute or two of struggling with it I put it back into first and shut it off...I drove my 2002 Camaro to work instead. It was a little hard to get it back into first but not bad. I understand that high performance cars from this era tend to have challenging transmissions when cold...but it seems some days this is more than that. Any thoughts? Car has 38K miles on it. Thanks. __________________ [COLOR="Red"][B]1995 Chevrolet Corvette ZR-1 #121, Red/Beige[/B][/COLOR] 2002 Chevrolet Camaro SS 35th Anniversary T-Top M6, LE #2823, SLP #6174 2017 BMW M3 DCT, Yas Marina Blue/Silverstone

08-09-2022	#2
DRM500RUBYZR-1 Join Date: Sep 2008 Location: Mullica Hill, New Jersey Posts: 2,566	Re: 1995 ZR1 Transmission Really Stiff...Sometimes Something is amiss. It should not be anywhere near as difficult as oyu have described. Two suggestions. First take it to a shop that will drain and refill the transmission with the correct lubricant. Mobil 1 or Amsoil are considered to be ideal for the ZF trans. Second, make sure that your clutch fluid is both clean and more importantly full. Once both of those have been done, if your effort is not greatly reduced then the transmission may have a mechanical issue. That eliminates the simple easily correctable causes. Good luck and keep us posted of your progress. Marty

08-09-2022	#5
DRM500RUBYZR-1 Join Date: Sep 2008 Location: Mullica Hill, New Jersey Posts: 2,566	Re: 1995 ZR1 Transmission Really Stiff...Sometimes The Castrol is fine as well! Marty

08-09-2022	#6
viper107 Join Date: Dec 2019 Location: st louis mo Posts: 746	Re: 1995 ZR1 Transmission Really Stiff...Sometimes car should shift like butter,do not force the shifter! its either got a tired clutch or a internal worn part or parts if the fluid change doesnt fix it __________________ 95 admiral blue z(sold)/ / 93 ruby z(sold) 91 steel blue z/95 aqua z haibeck 510, 91 callaway 415 areobody #5

08-09-2022	#7
lfalzarano Join Date: Feb 2011 Location: Clayton, North Carolina Posts: 1,133	Re: 1995 ZR1 Transmission Really Stiff...Sometimes Check your clutch fluid level under the ECM. If the transmission fluid hasn?t been changed, get it done. Sent from my iPhone using ZR-1 Net Registry __________________ Lou[COLOR="Red"][B][SIZE="4"][/SIZE][/B][/COLOR]