|
|
|
Post Reply |
|
Thread Tools | Search this Thread |
11-27-2009, 05:22 AM | #23 |
Just call me J.J. McClure
156
Rep 2,834
Posts |
Your tranny is fine. I had TONS of grinds in my first tranny, that thing was a lemon. But after BMW replaced it, I had a "lazy" grind happen to me once between 1st-2nd at about 3k rpm as well. The car is fine! The syncros in these trannies are made of CF, so they should withstand a lot of abuse.
Hey Harris, take your car on a test drive with a BMW tech and replicate the problem, they'll change your tranny without any questions asked. My second tranny is not plagued by the 1st-2nd grind. Thank God!
__________________
MODS: Meisterschaft GT Racing Exhaust / BMC Air Filter / UUC SSK & DSSR (Modded)/ RPI Scoops / Passport SRX Hardwired / Custom Wrap 3M Clearbra / 20% Tint / 50% Windshield Tint / Key Hole Delete / Matted Out Accessories / VRS Type II Diffuser / Smoked Reflectors / Euphoria 6K LED Interior Lights / Rear Fog Light Mod / 6000K HID's / 6500K LUX H8 Angel Eyes / RDash License Plate LED Kit / LED Xenon Reverse Lights
"M3 drivers have no friends" |
Appreciate
0
|
11-27-2009, 08:49 AM | #24 | |
Major General
285
Rep 6,007
Posts |
Quote:
Also, the clutch in my opinion is not heavy at all without the spring, it's just more linear in feel.
__________________
|
|
Appreciate
0
|
11-27-2009, 04:08 PM | #25 | ||
Major General
258
Rep 5,012
Posts |
Quote:
Quote:
|
||
Appreciate
0
|
11-29-2009, 03:52 PM | #26 | |
Second Lieutenant
27
Rep 228
Posts |
Quote:
The gears themselves are always in mesh. The syncros are cones (see last pic and you can see the cone) that speed up or slow down the shafts to allow the "dogs" to mesh, at which point the gears are locked to the appropriate shaft. Syncros prevent the interlocking teeth of the collar from engaging until it is spinning at the same speed as the one it is going to mesh against. When syncros wear down/wear out, they either slip or don't engage soon enough to get the collars spinning at the same speed before the teeth engage. When you "grind your gears" you're actually hearing the collar grinding. The gears themselves are always in mesh so you're not hurting them. There is still the potential for damage over time, but it's not the same as Here's a link: http://auto.howstuffworks.com/transmission1.htm |
|
Appreciate
0
|
11-29-2009, 04:03 PM | #27 |
Major General
285
Rep 6,007
Posts |
Most syncros I know of are brass, or some material softer than the gears, this way any grinding that happens damages the syncro not the gear.
__________________
|
Appreciate
0
|
12-02-2009, 02:14 PM | #28 | |
Major General
258
Rep 5,012
Posts |
Quote:
Only collars and gears (not the teeth but the 'female' dogs) seem to be able to grind. Now the question is if both the collar and gear could be damaged while grinding, or one is supposed to 'sacrifice' itself for the other . When a gear 'jumps' back to neutral, means the collar 'dogs' are rounded from grinding, and can't keep itself mated to the gear. I guess it doesn't matter if it's just one or both components, as tranny has to be opened up in that case. And although gear teeth are unaffected, the affected gear has to be replaced anyway due to worn dogs. My new question is how synchros can wear prematurely if knob is never held while driving. Hopefully both the gears and collars are strong enough to withstand some abuse, as it's practically impossible not to grind a gear at least a few times in the life of the tranny. Thank you all for your contributions . |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|