3rd Gear Downshift Grinds

durabond 72 · 12-03-2011, 08:53 AM

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I've had my 1M Coupe for a few days and have covered about 250km ...

Just wanted to know if anyone has grinded going down into 3rd gear (using heel-toe to downshift)? I've done it 3-4 times and only going down into 3rd.

I've been racing competitively for a number of years with no gearbox failures and have always been smooth on the gearbox of my street cars. But, for some reason I have found myself grinding a couple of times when only downshifting into 3rd. Although it has only been about 3-4 times, it is definetly 3-4 times too many.

Has any one else experienced this?

robertm · 12-03-2011, 09:05 AM

No man, never had issue. You think something is wrong with the tranny?

Dackelone · 12-03-2011, 09:10 AM

I would first change the trans fluid and make sure the correct fluid is in there! MTF-LT-5. Not LT4 or LT3, your trans needs LT-5. IF the trans still grinds after that... I am affraid your car will need a fresh trans - since BMW does not let its dealers rebuild trans/engines. Also make sure the correct amount of trans fluid is in the trans, some should spill out of the fill hole. G.L.

Mdawood · 12-03-2011, 09:12 AM

It's happened to me about 3 times. I am no professional driver but not a novice either. I think I was getting too excited and letting off the clutch early... Now Just taking my time up/down shifting, heel-toe. This car gets me pumped up!

Mdawood · 12-03-2011, 09:18 AM

Now that I read what I wrote- my grinding was completely due to driver stupidity! Idiot!

durabond 72 · 12-03-2011, 09:43 AM

I wouldn't think there is anything wrong with the tranny, it feels tight and sharp.

I think it's my mistake. I haven't grinded in years, but maybe it's just the low biting point of the new clutch. But, since it's only happening in 3rd I thought I'd throw it out there.

Good point on the fluid - Does anyone know what kind of fluid is specified for the 1M tranny?

But - other than that the tranny is a peach.

Die ///M Rakete · 12-03-2011, 09:52 AM

Quote:

Originally Posted by durabond 72

I've had my 1M Coupe for a few days and have covered about 250km ...

Just wanted to know if anyone has grinded going down into 3rd gear (using heel-toe to downshift)? I've done it 3-4 times and only going down into 3rd.

I've been racing competitively for a number of years with no gearbox failures and have always been smooth on the gearbox of my street cars. But, for some reason I have found myself grinding a couple of times when only downshifting into 3rd. Although it has only been about 3-4 times, it is definetly 3-4 times too many.

Has any one else experienced this?

Have you peformed the CDV delete mod yet?

HALOTHANE · 12-03-2011, 09:55 AM

Get rid of the CDV.

durabond 72 · 12-03-2011, 09:59 AM

what is CDV?

anubis · 12-03-2011, 10:02 AM

clutch delay valve

http://www.zeckhausen.com/cdv.htm

durabond 72 · 12-03-2011, 10:11 AM

By the sounds of what is described in that link it might just be the problem. Whenever the grind happens I always find myself wondering about the timing of the clutch and its engagement.

What is the change like once the mod is done - especially on the 1M?

Really, if you've timed the shifted perfectly if you miss the clutch on the downshift it still shouldn't grind (not recommended though!)

Thanks a lot. I'll give them a call on Monday.

anubis · 12-03-2011, 10:20 AM

Can't speak for the 1M but I can tell you that on the E46 it's pretty much night and day difference.

Also, check where your clutch biting pointing is and maybe diy a better clutch stop.

HALOTHANE · 12-03-2011, 10:51 AM

Quote:

Originally Posted by durabond 72

By the sounds of what is described in that link it might just be the problem. Whenever the grind happens I always find myself wondering about the timing of the clutch and its engagement.

What is the change like once the mod is done - especially on the 1M?

Really, if you've timed the shifted perfectly if you miss the clutch on the downshift it still shouldn't grind (not recommended though!)

Thanks a lot. I'll give them a call on Monday.

Make sure your shop knows EXACTLY how to do a CDV delete correctly. The 1M has a plastic CDV. Do NOT let them drill it. The metal restrictor diaphragm inside the valve needs to be pushed out with a metal pin. Drilling is only for metal CDV's, not found on our cars. Bleeding the clutch is also paramount afterwards, either with a pressure bleeder or pumping the pedal 50 times (self-bleeding system as per Active Autowerke). Do a thread search in this forum to find images and detailed instructions for your shop. Good luck!

HALOTHANE · 12-03-2011, 10:53 AM

P.S. The gearbox takes over 2000 miles to really settle in.....although the manual states 350-500 miles for break-in of transmission. You still should not experience grinding, however. Also, try heel-toeing without M mode....accelerator modulation is more linear without.

durabond 72 · 12-03-2011, 12:05 PM

Thanks. Though all grinds have come in regular mode.

speedM · 12-03-2011, 01:01 PM

i would think the stock cdv would give you more room for error, no? doing the mod would make the clutch engage quicker thereby less room for error.

from my experience, bmw's are really tight when new and need quite a few thousand miles to properly break in. so be more deliberate with your shifts and take your time when the car is new, it will thank you down the line.

CarJunkie · 12-03-2011, 11:37 PM

Quote:

Originally Posted by speedM

i would think the stock cdv would give you more room for error, no? doing the mod would make the clutch engage quicker thereby less room for error.

from my experience, bmw's are really tight when new and need quite a few thousand miles to properly break in. so be more deliberate with your shifts and take your time when the car is new, it will thank you down the line.

Good to know...I am finding the 1-2 shift to be slow. No grinding, just takes a moment before it pops in. I have not wanted to force it. Occasionally, the stars align and it goes quickly.

I am debating whether or not to do the CDV delete.

Reworking the clutch stop is a must as my foot has to extend to reach the bottom of the pedal throw. If I move the seat ahead, the geometry gets all wrong for the gas/brake.

speedM · 12-04-2011, 05:15 AM

Quote:

Originally Posted by CarJunkie

Good to know...I am finding the 1-2 shift to be slow. No grinding, just takes a moment before it pops in. I have not wanted to force it. Occasionally, the stars align and it goes quickly.

I am debating whether or not to do the CDV delete.

Reworking the clutch stop is a must as my foot has to extend to reach the bottom of the pedal throw. If I move the seat ahead, the geometry gets all wrong for the gas/brake.

1-2 shift will be a little tight at slow speeds, I'm sure that will loosen up over time. Make sure your clutch stop gives enough room to fully disengage your clutch. I've never been a big fan of those myself.

rapter · 12-05-2011, 10:00 AM

I just confirmed from my dealership that they put in the MTF-Lt-2 fluid in my car in place of the MTF-LT-5 fluid,

Can someone clarify what are the effects of the incorrect fluid being put into my car?

burnsniper · 12-05-2011, 10:17 AM

Quote:

Originally Posted by speedM

1-2 shift will be a little tight at slow speeds, I'm sure that will loosen up over time. Make sure your clutch stop gives enough room to fully disengage your clutch. I've never been a big fan of those myself.

I have noticed this when family members have driven the car. This seems to be somewhat dependent on engine speed. Short shifting 1st to second is a little tight. 2.5k to 5k it is smooth.

Mahlzeit · 12-05-2011, 10:55 AM

Don't touch anything. If the issue persists, take it to the dealer and reproduce it w/ a mechanic and/or SA in the car. You've got a warranty after all.

Let them try to tell you it's normal, and then figure out if you're going to start monkeying w/ the car on your own.

theshiningnova · 12-05-2011, 12:25 PM

Quote:

Originally Posted by 1MVO

P.S. The gearbox takes over 2000 miles to really settle in.....although the manual states 350-500 miles for break-in of transmission. You still should not experience grinding, however. Also, try heel-toeing without M mode....accelerator modulation is more linear without.

I believe the sport mode(WITH M button pressed) only makes the throttle responds faster to your inputs. It does not make the accelerator modulation any more linear.

It's much harder for me to heel toe without M button pressed cos I have to jab the accelerator much harder to get the rev up

12-03-2011, 08:53 AM	#1
durabond 72 Enlisted Member 11 Rep 39 Posts Drives: black Join Date: Dec 2011 Location: toronto iTrader: (0)	3rd Gear Downshift Grinds Featured on BIMMERPOST.com I've had my 1M Coupe for a few days and have covered about 250km ... Just wanted to know if anyone has grinded going down into 3rd gear (using heel-toe to downshift)? I've done it 3-4 times and only going down into 3rd. I've been racing competitively for a number of years with no gearbox failures and have always been smooth on the gearbox of my street cars. But, for some reason I have found myself grinding a couple of times when only downshifting into 3rd. Although it has only been about 3-4 times, it is definetly 3-4 times too many. Has any one else experienced this?
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12-03-2011, 09:05 AM	#2
robertm Major 450 Rep 1,358 Posts Drives: 2020 M2 Comp Join Date: Oct 2007 Location: dfw iTrader: (0)	No man, never had issue. You think something is wrong with the tranny?
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12-03-2011, 09:10 AM	#3
Dackelone European Editor 10532 Rep 22,992 Posts Drives: N54 e82 Join Date: Feb 2010 Location: Bayern, Germany iTrader: (1)	I would first change the trans fluid and make sure the correct fluid is in there! MTF-LT-5. Not LT4 or LT3, your trans needs LT-5. IF the trans still grinds after that... I am affraid your car will need a fresh trans - since BMW does not let its dealers rebuild trans/engines. Also make sure the correct amount of trans fluid is in the trans, some should spill out of the fill hole. G.L.
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12-03-2011, 09:12 AM	#4
Mdawood Lieutenant 122 Rep 569 Posts Drives: vo 1m Join Date: Aug 2011 Location: Florida iTrader: (1)	It's happened to me about 3 times. I am no professional driver but not a novice either. I think I was getting too excited and letting off the clutch early... Now Just taking my time up/down shifting, heel-toe. This car gets me pumped up!
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12-03-2011, 09:18 AM	#5
Mdawood Lieutenant 122 Rep 569 Posts Drives: vo 1m Join Date: Aug 2011 Location: Florida iTrader: (1)	Now that I read what I wrote- my grinding was completely due to driver stupidity! Idiot!
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12-03-2011, 09:43 AM	#6
durabond 72 Enlisted Member 11 Rep 39 Posts Drives: black Join Date: Dec 2011 Location: toronto iTrader: (0)	I wouldn't think there is anything wrong with the tranny, it feels tight and sharp. I think it's my mistake. I haven't grinded in years, but maybe it's just the low biting point of the new clutch. But, since it's only happening in 3rd I thought I'd throw it out there. Good point on the fluid - Does anyone know what kind of fluid is specified for the 1M tranny? But - other than that the tranny is a peach.
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12-03-2011, 09:55 AM	#8
HALOTHANE First Lieutenant 36 Rep 391 Posts Drives: INTERLAGOS ZCP Join Date: Jun 2011 Location: Anywhere fast iTrader: (0) Garage List 1990 BMW L6 (retired) [0.00] 2010 BMW 135i M-Spo ... [0.00] 2011 BMW 1M (adopted) [0.00] 1990 MERCEDES 190E ... [0.00] 2012 BMW M3 [1.00]	Get rid of the CDV.
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12-03-2011, 09:59 AM	#9
durabond 72 Enlisted Member 11 Rep 39 Posts Drives: black Join Date: Dec 2011 Location: toronto iTrader: (0)	what is CDV?
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12-03-2011, 10:02 AM	#10
anubis ... 27 Rep 30 Posts Drives: '09 e92 M3 Join Date: Mar 2008 Location: CA iTrader: (0)	clutch delay valve http://www.zeckhausen.com/cdv.htm __________________
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12-03-2011, 10:11 AM	#11
durabond 72 Enlisted Member 11 Rep 39 Posts Drives: black Join Date: Dec 2011 Location: toronto iTrader: (0)	By the sounds of what is described in that link it might just be the problem. Whenever the grind happens I always find myself wondering about the timing of the clutch and its engagement. What is the change like once the mod is done - especially on the 1M? Really, if you've timed the shifted perfectly if you miss the clutch on the downshift it still shouldn't grind (not recommended though!) Thanks a lot. I'll give them a call on Monday.
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12-03-2011, 10:20 AM	#12
anubis ... 27 Rep 30 Posts Drives: '09 e92 M3 Join Date: Mar 2008 Location: CA iTrader: (0)	Can't speak for the 1M but I can tell you that on the E46 it's pretty much night and day difference. Also, check where your clutch biting pointing is and maybe diy a better clutch stop. __________________
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12-03-2011, 10:53 AM	#14
HALOTHANE First Lieutenant 36 Rep 391 Posts Drives: INTERLAGOS ZCP Join Date: Jun 2011 Location: Anywhere fast iTrader: (0) Garage List 1990 BMW L6 (retired) [0.00] 2010 BMW 135i M-Spo ... [0.00] 2011 BMW 1M (adopted) [0.00] 1990 MERCEDES 190E ... [0.00] 2012 BMW M3 [1.00]	P.S. The gearbox takes over 2000 miles to really settle in.....although the manual states 350-500 miles for break-in of transmission. You still should not experience grinding, however. Also, try heel-toeing without M mode....accelerator modulation is more linear without.
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12-03-2011, 12:05 PM	#15
durabond 72 Enlisted Member 11 Rep 39 Posts Drives: black Join Date: Dec 2011 Location: toronto iTrader: (0)	Thanks. Though all grinds have come in regular mode.
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12-03-2011, 01:01 PM	#16
speedM Private First Class 2 Rep 139 Posts Drives: 2106 X3 35i, 1M, 05 MCS Join Date: Apr 2008 Location: S.California iTrader: (0)	i would think the stock cdv would give you more room for error, no? doing the mod would make the clutch engage quicker thereby less room for error. from my experience, bmw's are really tight when new and need quite a few thousand miles to properly break in. so be more deliberate with your shifts and take your time when the car is new, it will thank you down the line.
	Appreciate 0 Quote

12-05-2011, 10:00 AM	#19
rapter Lieutenant 71 Rep 485 Posts Drives: 1(M)other f*^#er of a car Join Date: Nov 2010 Location: Canada iTrader: (0)	I just confirmed from my dealership that they put in the MTF-Lt-2 fluid in my car in place of the MTF-LT-5 fluid, Can someone clarify what are the effects of the incorrect fluid being put into my car?
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12-05-2011, 10:55 AM	#21
Mahlzeit Lieutenant 37 Rep 582 Posts Drives: 1M Join Date: Jul 2007 Location: Location Location iTrader: (0)	Don't touch anything. If the issue persists, take it to the dealer and reproduce it w/ a mechanic and/or SA in the car. You've got a warranty after all. Let them try to tell you it's normal, and then figure out if you're going to start monkeying w/ the car on your own.
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