So I replaced my clutch/flywheel etc. with the kit from import parts pro about 3500 miles ago. I did the install myself with some help from a couple friends of mine. Everything went smooth. Well ever since I replaced the clutch It's been a little hard to get it into each gear. It's not grinding at all. So I assumed it wasn't the syncros going bad. (I know i shouldnt assume) I also replaced the master cylinder and slave cylinder about 1000 miles ago with the same results. I've bled the clutch numerous times and adjusted the shifter and clutch pedal about 10 times. I never got around to putting the stainless line in because the screw on the fender it attaches is stripped out. (I used a box wrench 10mm instead of a flare nut wrench) so my question is where do I start to try and fix this problem? I'm out of ideas. I had a friend of mine tell me that I could have a faulty throwout bearing or pilot bushing. Oh and when I replaced the oem clutch it wasn't worn out. It wasn't even close to hitting the rivets yet. I just wanted to start at the drive train because i plan to spray nitrous if I can ever get this problem sorted out.

I drive an 06 6mt 350z enthusiast with 95k miles
Any help would be greatly appreciated

 

Sorry for the long post in advance.

 

Stock fluid?

 

I put in pennzoil synthetic 75w90 then changed it to Valvoline synpower 75w90 about 1500 miles ago thinking that might be the issue.

 

The clutch fluid is dot 3 synthetic. Can't remember the manufacturer right this second.

 

http://www.performanceonline.com/ima...brakefluid.png
There's the clutch fluid I used.

 

Both of those are GL-5 gear oils. They are formulated for handling the higher pressures and shearing forces inherent to hypoid gears, such as your differential's ring and pinion. For your transmission, you want to use a GL-4 transmission oil. Pennzoil Synchromesh is a readily available option at most auto stores.

Will

 

Yeah you are having synchro trouble from the fluid. Go back to oem or redline's fluid that is spec'd for these transmissions and see how it feels.

 

What weight redline fluid? Or can you send me a link?

 

Redline MT-85. Do you still have the bottle for the old fluid you put in? Many gear oils come in both GL-4 and GL-5. The pennzoil syn 75w-90 definitely comes in both GL-4 and GL-5, so I would not get your hopes up on this being the fix.

edit: I googled the Valv. synpower 75-90 you were using it it is in fact GL-5 only, so maybe it will be as easy as just changing out the fluid. Good luck!

 

Is it possible that the pilot bushing or throwout bearing are faulty? And/or that the clutch isn't fully disengaging and that's why the gears are rough?

 

But I'm gonna put pennzoil synchromesh gl4 in it today and see if that changes anything. Thanks for the help guys.

 

I don't see how the pilot bushing would be the cause, did you not change this out for the pilot bearing included with the kit? Did you replace the throwout bearing when you did your install?

Also, are you using an aftermarket short throw shifter?

 

Yes I replaced the oem one with the included roller pilot bushing. And yes I'm using the stock shifter. H

 

And yes I replaced the throwout bearing with the included one.

 

I've always wondered about Pennzoil Synchromesh fluid. I must have a million posts spreading the word about Redline MT-85 and Nissan MTF as good fluids to use. Let us know how that works for you! Also, did you do your clutch job with a set of jackstands or on a lift? That must have been fun!

 

I actually am good friends with the manager of a local oil change place that I used to work at. So I used one of their bays for about 5 hours lol the transmission only weighs about 90-100 lbs which was very surprising. It's just awkward weight. If I end up removing the transmission again then ill do it on jack stands and use a little transmission jack.

 

So I replaced the fluid with synchromesh today and Its 1000 times better so better. I'm hoping it'll get a little bit smoother after the fluid gets hot a couple times and coats everything again. I guess I need to drive another 350z or g35 around here and see how there's feels before doing anything else.

 

You do realize that when you drain and fill you only end up getting like 3.5 quarts and I think the tranny holds like 9 quarts or more. You will need to do 3 fluid swaps (drain and fill) to end up with 93% new fluid. It is typically when you steer away from OEM fluid that you run into issues with the gear box. I would drive it for a 3 days and then drain and fill it again with OEM fluid and do it a third and final time. That is a cheap fix and should take care of most of your issues.

 

the manual trans holds 9 quarts? You sure about that???