Thanks, I'll start planning the rebuild.

 

sounds good, call those two places and see what they'll charge...it shouldn't be too much. There's another place near chicago I'd recommend called DRC. They do some good work as well. '02 Z all the bolton's with a 12 bolt and slicks running 12.6 on motor and he can't really drive. He abuses it like no tomm. and it holds. Has carbon syncros and the steel forks...works pretty good.

Chris

 

It has royal purple in there right now with about 14-18k miles on the fluid, what kind of atf were you talking about using, also what about synchromesh?

 

Wait, rebuild?

My car started to grind at very high RPMS from 1st - 2nd as well. And I just had it fixed. It may not be as serious as you think.

If you're lucky like me, your synchro's might be just fine. However, alone with the synchro there is a "blocker ring". They are fibrous rings and they are what bring the gear being shifting into up to speed. My blocker rings were partially blown apart, hense the grinding at high RPMs (4-5k) and it gradually getting worse (2k rpm shifts)

Pull the tranny and have someone take a look. In my case.. my badly worn clutch put a long of strain while shifting, and slowing broke apart the blocker rings.

 

thanks for the tip man!

 

from what I've always known blocker rings and syncros are esentially the same thing. Little thing like tomato, tomatoe...when you say it... But that's me. And The Royal Purple is synthetic I believe. You can go to Your local parts store and get Automatic Transmission Fluid for like $1.60/qt. I've found that that usually lasts the longest and actually the least amount of wear on the tranny. It's funny that the cheap stuff works when you beat on stuff (I do, and I will admit it).

This is all just from my experience.

Chris

 

Not to doubt you or anything, but have you had the trany fluid anylized? Just trying to see why you suspect the regular stuff to work better than the synthetic. On www.bobistheoilguy.com they talk about this tranny a bunch with lots of conflicting results so I was just curious

 

Well.. I am, by no stretch of the imagination, a tranny expert But from what my tranny guy explained to me before he knew exactly what was wrong, he said he couldn't give me a quote on the price because it could just be the blocker rings. But it could be the rings AND the syncro, or it couldd even be the rings, syncros AND gear that is damaged.

I got lucky and it turn out to only be the blocker rings. I didn't have to replace my syncro. I figured the rings are part of the syncro assembly.

lt4 fd: when was the last time you replaced the clutch, out of curiosity? It just sounds all to familiar to my experience

 

umm my friend replaced it before I got the car like 20k or so ago...

 

Hmm.. well, do you know if your clutch is worn or not? If you're not sure.. try this test.

While idling and the clutch pedal in, stick it in 3rd gear. Now with your right foot, slightly hold the brake and rev it up a bit at the same time. Now let out the clutch quickly, but smoothly (don't dump it). If your clutch is good. It should stall or be very close to it. If you just sit there and you can hear it rev.. it's worn out and slipping. Don't try this test too much.. it generates a trememdous amount of heat and clutch wear.

If your clutch is worn out.. every time you shift it is putting a lot of strain on your syncromesh unit. Specifivally your blocker rings. The blocker ring is what is actaully rubbing up agaist the gear you are shifting into, and brings it up to speed with the mainshaft. Also.. the grinding noise you are hearing, is actually not the gears themselves, again, it's the teeth around the blocker rings.

My best advise.. drop the tranny and have someone crack it open and have a look.

Good luck.

 

i had the samev problem, jusr changed the clutch and it was all good. i assume the clutch disengaging wasn't as fast as the shift

 

1-2 shift is my fastest shift.... ill try a 3-4 shift sometime on the highway and as long as I do it as fast as teh 1-2 shift it should grind if its the clutch right? If not its most likely the synchros correct?

 

Back again after the car was down for a while and Ive learned a few things since so I have a better understanding of what you guys were talking about... One thing I didnt understand re-reading the post was how a worn clutch puts strain on synchros, which doesnt apply to me since my clutch never slips unless I make it... very grippy. I think Ill really have to just go out on the highway and slam every shift through 4th gear and see if it does it in all gears(mainly 1-2 and 3-4 since those are shifted about the same speed) or just certain ones. If in all gears Ill check for leaks and bleed my clutch, if its just certain ones I guess its the tranny and Ill change the fluid and see if it helps if not screw it untill the clutch goes bad or I cant shift since it doesnt seem to effect normal shifting at the moment...

 

I did not read all the posts just a few. I just got back my M6 back from a rebuild. I had pretty much the same problems 1-2 small grinding noise which got worse in time. 2-3 grinded a little but not to much. If I shifted slowly at low RPM's 1-2 would shift ok any thing that involed hi revs grinded. Rodney at RPM transmissions showed me one of my syncros. It has a beveled edge on the inside with a glued on friction pad that will grab another piece to stop it to let you change gears without grinding. Well the problem with mine was that the friction pad simply just fell off. This caused the snycro not to stop the other piece which in turn caused the grinding. He replaced all the snycros and installed some steel pins that are used in the dodge viper transmission along with some other stuff. I am by know means an expert in transmissions but everything he told me seemed logical. I should have it back together this weekend, and I'll let ya know how it feels. BTW I was using Mobil1 and he had told me that he has only seen one other M6 lose its friction pads on one other tranny. That guy also was using Mobil1. He told me to use Valvoline ATF. I have always used Mobil1, but if this will help keep the friction pads from coming unglued then what the hell I'll try it. Hope this helps

 

Thanks man, if you shifted more slowly at high rpm's would it still grind.. Im not saying granny shift but just not a death slam?