I have a 1978 280z 5 speed.   I installed a transmission service kit from Z Car Source of Arizona a while ago.  Attached is the order form.   Yesterday was the first time I was able to take the car for a long drive.  When I get to 2500rpm the clutch slips in 2nd and 3rd gear and I can get no more power until I change gears.  Has anyone had issues with this kit.  I am a novice in working on cars so any advice on troubleshooting would be greatly appreciated.  

SO-100005509.pdf

Did it come with a new throwout bearing sleeve (aka collar)?  I tried to find the list of parts in the kit but the company has shut down.

It's not clear what is in the "kit".

Edited October 23, 20223 yr by Zed Head
+ i

The throwout bearing sleeve looks like this.  The bearing presses on to it.

https://www.thezstore.com/product/2158/factory-clutch-collar-75-83-z-zx-2-2-82-83-280zx-turbo-84-89-300zx-non-turbo

to be honest I cant remember if it came with the sleeve.  I did all the work in early 2000 but just got the car back on the road a few months ago. 

 

This old thread might help.  You can take some measurements before you take anything apart.  It's the opposite problem, your clutch fork might be too far forward.  The "collar" might be holding the clutch disengaged.  Not applying full force.  People have reported that also.

Of course, it could also be an oily clutch disc.  

 

Do you have some free play at the top of the clutch pedal? 

Going to gather more info this weekend when I get a chance to work on it again

I took a couple of measurements.  Does this seem right?

 

Do you have play at the top of the clutch pedal? If not, that measurement is worthless as the clutch isnt moving its full amount. 

When you say play do you mean loose and squishy.  My clutch pedal does not feel like that.  Is there an adjustment I should try. Sorry for the novice questions

Reach down and grab the pedal. When you push it with your hand it should have some free play before you feel the pedal touch the master cylinder rod. If you press the pedal and it is instantly "hard" then you dont have any free play. That would be like driving with your foot on the clutch pedal. Free play ensures that the master has no pressure on it and allows the clutch to fully engage. You should be able to adjust the free play under the dash on the master. It looks like your slave cylinder is non adjustable so you may need to adjust the master. 

 

Maybe check the service manual for proper amount and a visual of how to adjust.