Welcome to the Connecticut Z Car Club Forums




Username:  
Password:  
Log me on automatically each visit
Register 
It is currently Thu Mar 28, 2024 2:15 pm
Welcome to the Connecticut Z Car Club Discussion Forums   
If you have trouble logging in or encounter any issues, please send an email to webmaster@ctzcc.com.

All times are UTC - 5 hours





Post new topic Reply to topic  [ 4 posts ] 
  Print view Previous topic | Next topic 
Author Message
PostPosted: Sat Jun 11, 2016 7:15 pm 
Offline

Joined: Fri Dec 25, 2015 7:39 pm
Posts: 697
Location: Long Island, N.Y.
I'm not exactly sure just what each part of the manual transmissions is supposed to do, so pardon my lack of knowledge. When shifting from 1st to 2nd I can feel the gears meshing through the shifter but not hearing any grinding noises. Would that be a synchromesh issue or a clutch issue? Also, the gear will grind occasionally (not every time) when it's put into reverse from a dead stop (synchro or clutch?). When shifting from 2nd to 3rd I think I can feel the gears meshing, too. I recently changed the transmission fluid with MT 90 synthetic hoping that would resolve some of these issues but it hasn't so far. NORMAL or needs further investigation?
Is the need for SOME force (with NO grinding) to get the transmission into the different gears normal? Or should it be resistance free like when the engine is not running? Would an experienced transmission shop be sufficient to work on this or would it be preferable to use a 300ZX specialist/mechanic?
Thanks for your opinions and thoughts.

HowardJ

_________________
1985 300ZX- GLL Dark Pewter Metallic - Survivor


Top
 Profile  
 
PostPosted: Sat Jun 11, 2016 7:53 pm 
Offline

Joined: Wed Apr 09, 2008 5:53 pm
Posts: 14779
Location: CT
Finding reverse from a dead stop is often an issue for many cars. That's because the reverse shaft (or counter shaft) continues to spin a little after you de-clutch. My solution is to select a forward gear momentarily to stop the rotating shafts, then snick the lever into reverse. The balk rings/synchroniZers are on the forward gears. Reverse doesn't have one on most transmissions. Selecting a forward gear uses those synchroniZers to stop the shafts and allow a smooth shift into reverse.

Based on some of your prior posts, it also sounds as if your clutch might not be disengaging completely when you press the pedal. That would leave a very small pressure on your gears even when you de-clutch, which would make shifting a little harder than it should be. Everything about the Z is adjustable, including the pedal travel. Laying upside down under your dashboard like a coal miner, you'll notice a pedal screw-adjuster for the brake and one for the clutch as well. Turn the clutch pedal screw to allow your pedal *just* a little more travel. Also, the hydraulic clutch slave cylinder (mounted on the transmission) is adjustable. That's trickier and you should read the shop manual about adjusting your model. I found the "sweet spot" on my clutch cylinder is less than 1/8" wide. Beyond that in either direction lets the clutch slip under load, or doesn't disengage completely when I depress the pedal. Once I found the perfect degree of adjustment, I stole my GF's nail polish and painted a witness mark along the adjusting rod and cylinder housing. That locked them together and also served as a reference point for the next time I needed to remove anything ~ I wouldn't have to play adjustment games again, but could just screw the adjusting rod in until the nail polish matched up. She never knew.

_________________
1970 240Z


Top
 Profile  
 
PostPosted: Mon Jun 13, 2016 2:11 pm 
Offline
User avatar

Joined: Wed Feb 29, 2012 11:44 am
Posts: 588
Location: New Haven, CT
Grinding when going to R is pretty common. Like Frank mentioned, I always go into 1st then go into R.

Your car is a '85 non turbo, correct? This should have the 71C transmission which is pretty reliable. 84-85 turbo cars came with the borg warner T-5 which is notoriously weak and feels very notchy.

I have the same transmission and I have felt some resistance in the shifter when it goes into the various gears, not a lot but it's not totally without feedback.

Some cars use linkages on the shifter which dampen out the "feedback" that you feel on the stick when you move it into gears. Nissan stick plugs straight into the forks so you can feel it actuating a little more directly. Hard to say without seeing it myself, but I think what you are feeling is probably normal.

_________________
Justin
1986 Z31 NA 2+0


Top
 Profile  
 
PostPosted: Mon Jun 13, 2016 9:48 pm 
Offline

Joined: Fri Dec 25, 2015 7:39 pm
Posts: 697
Location: Long Island, N.Y.
Thank you Frank and Justin for your input. I think that there may be air in the hydraulic fluid line because I heard a swishing sound when I manually manipulated the clutch fork fore and aft where the slave piston connects, so I will attempt to bleed the line at the slave cylinder and the proportioning valve splitter thingy. I'll update when work is done. :roll:

Howard

Update:
The swishing was the pumping of fluid into the rubber boot of the slave cylinder. It's now been replaced and properly bled. 8) :mrgreen:

UPDATE to the Update:
Still getting some shifting feedback. I'm going to start a new thread to ask about the clutch pedal height. Zee yah.

_________________
1985 300ZX- GLL Dark Pewter Metallic - Survivor


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 10 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  









Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
mile200 v1.0.1 designed by Team -Programming forum- .