280Z 5th gear synchro's gone bad?

[FunkytownZ]

Hi all -

I noticed when i bought my Z three months ago it was tough to shift into 5th gear... either the gear was hard to find, or the shift once the gear engaged was a little rough.  I thought this was due to sloppy shifter pin and bushings - I've bought new but yet to replace (need some special tools to knock old bushings out and press new in).

A couple weeks ago, I shifted into 5th and went to release the clutch and it popped the shifter back into neutral. 

Since then, I can shift into 5th at lower speeds and RPM's, but not during hard acceleration.  same result, pops the shifter back into my hand and into neutral.

Is it a synchro issue?  Or could it be something bigger?

Thanks in advance.

[Zed Head]

I can't remember exactly, but "loose countershaft nut" and "broken shift fork roll pin" come to mind.  If I recall correctly, neither is huge or expensive deal but both require removal and disassembly of the rear case from the adapter plate.  Sunchro problems can make it difficult to get in to gear but once it's there it stays there.  Popping out of gear is not a synchro problem.  The fact that it's changing over time suggests the loosening nut problem.  Probably want to catch that early.

[FunkytownZ]

I can't remember exactly, but "loose countershaft nut" and "broken shift fork roll pin" come to mind.  If I recall correctly, neither is huge or expensive deal but both require removal and disassembly of the rear case from the adapter plate.  Sunchro problems can make it difficult to get in to gear but once it's there it stays there.  Popping out of gear is not a synchro problem.  The fact that it's changing over time suggests the loosening nut problem.  Probably want to catch that early.

Awesome Zed Head - thanks for the response. That's the plan - just was hoping it wasn't real serious


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[Chickenman]

Delete. Just found out OP has a 280Z. My Information not relevant.

Edited April 4, 2017 by Chickenman

[Chickenman]

Delete. Double post.

 

Edited April 4, 2017 by Chickenman

[siteunseen]

You may be able to get it to stay in gear by grinding the shifter a little, that's what fixed mine.  When you take it out to replace the bushings look for nicks at the front and backside down at the bottom above the ball.  A few people have had issue with that and a little grinding fixed there's too.

 

[FunkytownZ]

yea i remember having those knicks on my shifter when i took it out and looked it over.. 

[Chickenman]

2 hours ago, siteunseen said:

You may be able to get it to stay in gear by grinding the shifter a little, that's what fixed mine.  When you take it out to replace the bushings look for nicks at the front and backside down at the bottom above the ball.  A few people have had issue with that and a little grinding fixed there's too.

 

I remember seeing that thread and was looking for it. Do you have the link?

 

[Zed Head]

The shifter would be the first place to look.  It's been talked about a lot, I assumed that you would have looked there.  Here's the thread, #86 is where the shifter interference pops up.

 

[EuroDat]

If you have the console out. Remove the rubber boot on the floor and take it for a spin and see if it still does it. The boot can sometimes cause this problem, especially if the rear transmission mount is worn and sloppy.

Does it clunk when you accelerate and de accelerate. A loose rear cluster gear will often make a clunk sound when it moves back and forth. Compare it with 3rd.

Edited April 4, 2017 by EuroDat

[FunkytownZ]

9 minutes ago, EuroDat said:

If you have the console out. Remove the rubber boot on the floor and take it for a spin and see if it still does it. The boot can sometimes cause this problem, especially if the rear transmission mount is worn and sloppy.

Does it clunk when you accelerate and de accelerate. A loose rear cluster gear will often make a clunk sound when it moves back and forth. Compare it with 3rd.

i was also thinking it might be the boot because I added those shift boot clips to hold the leather boot in place and thinking when it tightened the boot it might be interfering with 5th gear and the long reach.

so you'd recommend removing the leather boot AND the rubber boot?  or just the rubber boot?

No, does not clunk in 5th and no other gears clunk either

[Zed Head]

I would remove all of that stuff, take the shifter out and put some machinists blue or even black sharpie, or paint or a piece of tape on the spots of the shifter that site showed in the other thread, then go drive it.  It will either work fine and you'll know it was the boot, or it won't and you'll have some evidence on the shifter.  You might find it's some other weird thing like a console wire hanging or the console doesn't fit right.  

Edit - sometimes you just have to do what's necessary to see the source.  I was working on some plumbing yesterday trying to find a leak and I finally just stuck my head down on the concrete so I could see the bottom of the fitting.  The leak was not coming from where I had calculated from the landing point of the drops.  I wasted a lot of time trying to brain it out, when a little dirt on my head and some contortions would have found it earlier.

Edited April 4, 2017 by Zed Head