G35 grind 2nd sometimes

[SlashBack]

Hey I have a 2005 Infiniti G35 6mt. When im just driving normally Im shifting 1st to 2nd with occasional grinding. Seems to happen more frequently when I 1st start it up and the engine is colder. When I crank out the gears I never have a problem the engine has had time to get to get up to temp. Also noticed a lot of rattling when shifting with the window open especially from a stop. I initially thought bad synchro or shift linkage loose. But leaning more twords low trans oil and or need clutch.

Also when I 1st start driving 1st gear stays engaged even when I push the clutch in maybe this is why 2nd grinds.

Trying to get some feedback before I go to a shop thanks.

[audtatious]

How old is the clutch?

[el_blacky06]

I get the same effects on my 2007 Altima 2.5 and assuming that my clutch is well over 100k miles into it, it can definitely be the clutch

[telcoman]

Sounds like a clutch problem to me.
If you drive a stick shift properly and don't slip the clutch it should last around 200k miles.
I had 171796 miles on my 06 G35 when I traded it in last August and still had the original clutch.

Telcoman

[SteveTheTech]

Sounds like a trans problem to me.

Sounds like the synchros are toast.

Incorrect fluid could make this worse.

If flushed you might notice brass powder in the fluid too.

The noise that you would hear with the pedal pushed in at idle would be either a partially sticking pilot bushing or (more likely) a worn throughout bearing.

If you drive a stick shift properly and don't slip the clutch it should last around 200k miles.
I had 171796 miles on my 06 G35 when I traded it in last August and still had the original clutch.

Exactly.

[el_blacky06]

Thanks the the reply, for the synchros how does it work?
I didn't noticed the pieces of metal since I had drained & filled the transmission fluids but never flushed it out

[SteveTheTech]

I think if you see what the synchro is and how it works you might get a better idea of how it could fail and what it would feel like if the synchro is not able to speed up the main shaft before the driver has completed the gear change.
[youtube]http://www.youtube.com/watch?v=XunM7yUC06M[/youtube]
The synchro section starts at 2:10

[SlashBack]

Thanks all for posts. My car has 66k miles. Im 95% sure the problem is fixed now. I took the car to a good shop (needing a battery), but hey found the clutch switch was going bad. I have yet to grind a gear.

Thought I might add this for possible cheap options to anyone having similar problems.

[SteveTheTech]

That is quite interesting. Although realistically the only thing the clutch switch does is send a pedal position input to computer, to allow the car to start. There are two plugs on the transmission, one for a speed signal and one for reverse lights. Any grinding associated with a gear change would be a mechanical item and totally separate from any sort of electrical concern.

I am glad to hear that you have no heard the noise, but I wonder if it has more to do with an increase in ambient temperature.

The most common complaint associated with a failed clutch switch is a no start.

[SlashBack]

That is quite interesting. Although realistically the only thing the clutch switch does is send a pedal position input to computer, to allow the car to start. There are two plugs on the transmission, one for a speed signal and one for reverse lights. Any grinding associated with a gear change would be a mechanical item and totally separate from any sort of electrical concern.

I am glad to hear that you have no heard the noise, but I wonder if it has more to do with an increase in ambient temperature.

The most common complaint associated with a failed clutch switch is a no start.

I was having an occasional fail to start due to the switch and I had occasional grind on 2nd gear. I agree with possible ambient temp being a factor. Ill have to check when winter comes again. I'm not sure about all the functions of the switch. It seems to work much better now. Currently I do have a lot of racket if i get out of my car and listen to it idle in neutral. Probably need a clutch?

[SlashBack]

Little update:

I wanted to ask SteveTheTech or anyone reading. I think I am having trouble with the master and/or slave cylinder(s). If i drive for 30+ mins in the heat the clutch pedal will start to stick and I loose 1/2 to 2/3 of the total clutch pedal travel distance opposed to the "normal", non-sticking, cooler clutch pedal operation. I am not getting gear grinds but I can tell the gears aren't always as smooth as they should be. Also its hard to predict when the clutch will catch in "normal" operation and can be different threw out the same drive to the store or w/e.

My Theory: Because of this Im thinking this works both ways for me and the transmission. For example when I engage the clutch maybe the cylinder is partially extended or has a latency. Therefore when I shift can create rough operation even grinding or the gears.

Any supporting or opposing information welcome. Thanks.

[el_blacky06]

When the slave cylinder is out, usually you'll see a decrease in the clutch-brake fluid (whichever applies to the g35). The fluid should be leaking from the transmission causing the clutch to feel like it's engaging 2/3 of the way and it will get more worse until you replace it.

For the master cylinder (in my case), all the oil litteraly shoots out of the brake fluid area so it will be all over the engine causing the clutch not to engage and the clutch pedal will stay down