Not sure how many of you guys have had the 6th gear 'grind' issues, but i have always notice it happen randomly. Seems to be doing it a little bit more, but you can never get it to replicate it at the dealer. Told them i'd keep an eye on it.

Tonight, my friend drove my car while we went to return a Lexus we detailed earlier today. He said he got it to grind twice so on the way back, I experimented.

Tried skipping gears. 3rd to 5th on the freeway, no grind. 4th to 6th (revs at idle) no grind. 4th to 6th with the revs matched to what 6th would normally sit at (about 3k) and it grinds like a ****.

Now, thats not normal, right? Because I think I am gonna call up the dealer tomorrow and tell them that I can now replicate it since it would always do it randomly.

Also I am going to have them look at my brake judder because it does it fairly noticeably on the freeway.

 

I hear skipping gears for a transmission that is not design for it, ie Corvette, is bad for it. On my car, I get minor grinding when it is cold out. Have you change your fluid?

 

[QUOTE=Iilac;6026490]I hear skipping gears for a transmission that is not design for it, ie Corvette, is bad for it. QUOTE]

No offense, but this is bull.

My trans was replaced 3 years ago. First 6 will grind. Later 5 will grind, too. Never had a problem since. My driving habits are the same. I have put 67k on it after replacement. The mechanic said "input shaft bearing was bad". Go to the dealer. Complain until you are blue in the face.

 

No problems here = not normal!

 

[QUOTE=07-G35-MT/S;6026553]No offense at all. That's why I put I hear/read on other forums that skipping gears on manual tranny is not good for it. I have never skip gears on my cars and lock on wood, my transmissions have all been good. I just do not see the point of skipping gears but I have not read any tests done specifically to test the harm of skipping gears.

 

I don't normally skip gears, but it is the only way I can replicate the grind that 6th makes (randomly).

I notice it a LOT when I am like, hauling *** in 4th or 5th, and decide to slow down but my revs are high, then as I shift into 6th to slow down, it grinds. Thats the best I can explain it, but that is generally at high speeds IE over 100 and I don't really know how to explain that to the dealer... other than doing the skip gear trick.

BTW, just to test my theory, I drove my dads 09 Corvette tonight, and my brother in laws 04 STi and NEITHER of them grind when I skip from 4th to 6th.

 

i dont do that often but whenever i have skipped 5 gone 4->6 while making sure the rpms is matched, i have never had a grind

 

my 5th gear grinds when the car is usually cold and when i shift from 4th to 5th semi quick
i've been trying to avoid it by just taking my sweet *** time from 4th to 5th when its cold
but i still forget from time to time
after the car is warmed up and i've shifted thru all gears i dont have a problem with 5th

 

No grinding here in any gear. Skipping gears is fine but I would stay away from trying to go into 6th when the rpms are any higher than the revmatch point (i.e. don't try to go into 6th with the rpm's over 4k). I could see why any tranny wouldn't like that. 6th is a gas mileage cruising gear so there should be no reason to force the issue. Treat 6th similar to 1st in the sense that you only apply very light pressure on it and the car will let you know when it is willing to accept it (like when rolling at 5-10 mph out of gear and wanting to get back into 1st). I go from 4th to 6th all the time when getting on the freeway and have no issues as long as I don't try to force it. Hope this helps.

 

Taking it over tomorrow to see what they have to say. They are gonna have the shop foreman ride along with me.

 

Modern cars have synchromesh with makes sure the engine and tran are spinning at the same speed when upshifting.

I had my tranny replaced by the dealer for bad sychromesh at 36K. My car would grind into 5th under 45-50 mph and would shift like butter above it.

Look up synchromesh gears and you'll see skipping gears is bad for it ... same as double clutching in a modern car but thats another debate.

edit: If you rev match correctly, you wont hurt your tran but why risk it.

 

Took my car to the dealer today and took the shop foreman for a ride. He heard the grinds ( a couple times...) and said it shouldn't be doing that. Made an appointment for Monday and will hopefully be getting a new transmission!

 

A new MT would be a great deal. I hope they do it for you.

 

Hope you get a brand new trasmission which is a good news.

 

I think if you got him to verify it, and your clutch is working properly, and you are within warranty coverage, then you are virtually assured a new tranny.

Congrats!!


btw, the reason 5th and 6th are more susceptible to grinding is that they only have one syncro, whereas 1,2,3 have three syncros and 4 has two.