Today, I experienced a grind while shifting into 4th. It happened when the ambient air temp was very low (13 F) and went away once the car warmed up. It happened at least the first 4 or 5 times I tried to shift into 4th. Has anyone else had this problem before? My warranty is expiring soon and I need to know how to approach the dealer with this issue. My car only has 16k on it, and I am not very happy.

 

There is grind and there is GRIND.

When the car (read tranny and tranny fluid) is very cold, it is not unusual for some M12s to make a little noise or occasional grind (not GRIND). If it makes a GRIND when cold, then it would concern me. But if it is just a grind that disappears when the tranny is warm, I'd say don't worry about it.

Mine occasionally gives a slight objection on entering 2d gear at ambient temps below 25 F when the car is first started. It's fine above that. And I've had no tranny issues on any of my C4s or C5s.

Ranger

 

As Ranger said, I get a slight gring going into 2nd if it's very cold out & the car isn't warm. It goes away when warm. Sometimes it almost feels like cags is back as well. Just shift slower & easier, or go 3-5 until she warms up. :seeya

 

I would say it was a GRIND. There was definite resistance in the shifter and a bad noise. (I am not talking about the usual noises associated with the T-56 tranny) My 4Runner with 230k that probably hasn't had a tranny fluid change since George Bush Sr was president doesn't grind, so I am a little disappointed in the Z06 right now. Is there any fluid you would suggest to remedy the problem or should I bring it to the dealer and make them fix it?

 

The shift was as slow and easy as I could possibly go, and it was at around 25 MPH, so very low engine RPM and it still ground

 

Does your tranny grind (or GRIND) under any conditions besides the very cold temps you described in your lead post?

I tried Redline fluid in my 01 Z06 tranny at 15K miles, just to see if the raves it received were correct. I found that I didn't like the feel it gave to the shifting action. So on my 02 I have kept the tranny fluid stock when it was changed at 15K miles.

If you decide to take your tranny to the dealer, keep in mind that the tech will need to be able to duplicate the problem. Given the circumstance you describe, that will be hard to do.

Ranger

 

My FRC started grinding around November when it got cold up here in MA. It would do it only when the car was cold, once it was warmed up it was fine. It was typically 3rd and 4th. If I was in 2nd, I could push in the clutch, shift to 3rd (grind), then shift directly into 4th without moving the clutch and it's grind again.

I'd recommend trying a good fluid before you start freaking. I'm gonna start with GM Syncromesh (it's a semi synthetic). If it doesn't get better, I'll try a full synthetic. If it doesn't get better it will be rebuild time.

I'm not TOO worried about mine, it only showed up in 20 degree weather or below, and it had never had a problem before. Only 23k miles on the car too.

Dope

 

Has anyone had experience with the shift forks being bad???

 

Not I but there's talk of a recall of the shift forks.
BTY IMO your grind is do to the cold weather.
:cheers:

 

What oil temp is this occurring at? You said it was 13F air temp but what about the oil temp. I personally never even put it in gear until oil temp is at least 40F and then keep it less than 3K RMP until oil temp >150F.


[Modified by Piranha, 5:22 PM 3/23/2004]

 

I don't recall what the oil temp was. If I had to guess I would say about 40-50 F since the car was running for ~2mins before this shift. I babied it on the shifts and it still ground. Also, there is no trans fluid temp gage so it's impossible to know the temp of the tranny fluid.

 

I had to replace 3rd gear & the synchros. I don't think they replaced the fork though. I forget. I don't think the engine oil temp would affect the tranny...but what do I know?

 

Mine had an occassional GRIND going into 4th while it was WOT at Laguna Seca. Probably around 100mph. I don't recal if it was temperature related. I just made sure I had the clutch in all the way (i.e. - no quick shifting)

BTW - it is not impossible to tell tranny temp. When the tranny gets too hot, the computer tells you until you reset it. After you hit the 'reset' button the first time, it will give you a digital read out of the temp. If you don't hit the reset button, the temp reading will stay up there and be real-time. I don't know how to bring it up under normal conditions.

If someone knew how to do this, you would rock! :D



[Modified by Too Tall Z06, 4:18 AM 3/25/2004]

 

you have damanged the aluminum shift fork....

you need to get the iron replacement that GM makes and now installes in mid 2003 and later cars.

i have damagd 3 or so shift forks.. but now have all iron replacements that work wonderfull
the part is 59$ but all you have to worry about is the labor..
unless you bvought the extended warranty..
there is TSB - technical servce bulletin about this..
you might can get them to replace it, even if your car is out of warranty.. depends on how much hell yor willing to raise....

i got a new engine in mine for raising hell about piston slap.. i also got a new clutch pressure plate and flywqheel, installed when they did the clutch for upgrade...
because i told them my car hung in forth and i damaged the clutch tryign to drive it around in 4th.. because ti happened on a trip.


good luck


rb

p.s. many of the performance shops.. and my own factory trained GM mechanic recomend not using sncho mesh in the C5.
this is because the C5 is prone to over heating the manual trans because of lack of air flow...

the sunchro meshg has been proven to retain heat more than standard mercon 4.
so go get you some iron shift forks.. then fill her up with good ol dextron red atf fluid...

he also recomends changing it ever 2 motor oil changes if you are a "spirited" driver...

LOL


[Modified by pwrshhftd, 11:51 PM 3/24/2004]

 

pwrshhftd,

Thanks for the info. It is still under warranty, so I'll see what I can do to get them replaced.

How easy/hard is it to replace the tranny fluid? Never done it before.