|
|
SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS! |
Post Reply |
|
Thread Tools | Search this Thread |
12-02-2012, 05:20 PM | #1 |
Private
11
Rep 81
Posts |
Newbie Questions: 1st,2nd Shift Jerkiness and clunk?
So finally got myself an 07M a couple of weeks ago and I love the car...BUT I cant shift the MF'r smoothly. First to Second is jerky and when I and shifting during normal driving I feel like ive forgotten how to drink a manual (i've been driving manuals for 16 years).
I'll be driving press the clutch to the floor and its like the transmission isnt ready for me yet so I wait. The jerkinesss is embarrassing when someone is in the car with me and I find myself over trying to drive smooth. Occasionally i'll get into a groove and all is good but then i'll do it again and get annoyed. The other thing ive noticed is when I and moving slowly like when parking I hear a small clunk when I press the clutch as the engine disengages from the tranny. Is the shifting all the dumb CDV I keep reading about? Is the clunk a worn quibo (if this guy has on like my 99M did)/. BTW I have 12k miles on the car if it helps to know what my issues are. Thanks and sorry for the rant. Marvin |
12-02-2012, 05:54 PM | #2 |
Private First Class
14
Rep 153
Posts |
I'm just a newbie so I'm not sure if the Z4MC has a CDV. Could this be the problem?
http://blog.bavauto.com/10625/bmw-di...e-removal-cdv/ |
Appreciate
0
|
12-02-2012, 06:02 PM | #3 | |
First Lieutenant
27
Rep 341
Posts |
Quote:
Step 1 - remove CDV Step 2 - bleed slave cylinder thoroughly Step 3 - install a clutch stop to take up any excess travel in the pedal Step4 - install firmer transmission mounts Still, you'll need to be a bit patient with the 1-2 shift
__________________
|
|
Appreciate
0
|
12-02-2012, 06:25 PM | #4 |
Dog Listener
711
Rep 7,850
Posts |
^WHS
It's also necessary to keep the revs up a bit by not coming completely off the throttle 1st - 2nd. Almost like rev-matching a downshift--the revs drop quickly and that leads to that "I'm driving my first MT" experience. Ditching the CDV also helps--but even w/o it if you don't keep the revs up a bit you'll not be smooth. Here's a thread on the transmission mounts. I highly recommend the RE neoprene for street use. The "clunk" is normal BTW. I've been in a lot of Z4Ms and they all do this. Last edited by Finnegan; 12-02-2012 at 07:01 PM.. |
Appreciate
0
|
12-02-2012, 08:33 PM | #5 |
Colonel
1226
Rep 2,935
Posts
Drives: Anything
Join Date: Apr 2010
Location: SoCal
|
Welcome...these are just the first of all the little peculiarities of the M. I will guaranteed that you will discover a lot more
|
Appreciate
0
|
12-02-2012, 10:18 PM | #6 |
Second Lieutenant
22
Rep 251
Posts |
Congrats on your new car... like others mentioned, the revs come down fairly quick and 1st to 2nd is a bit slow.... so you either rev the engine while shifting or let the clutch half way and you'll feel when it engages.... and then release it completely while accelerating.... but the 2nd option might wear your clutch a little. Well... do what people mentioned above, then you can look into upgrading your motor mounts and that might solve about 90% of the shifting issue... simply cus 2nd gear is a bit stubborn and there is not cure for that.
The clunking sound is natural... when parking or driving slow.... push the clutch slow and you won't hear it. Good luck. |
Appreciate
0
|
12-02-2012, 10:39 PM | #7 | |
Major
159
Rep 1,108
Posts |
+1.
Also, clutch in slightly before coming off the gas before shifting Quote:
|
|
Appreciate
0
|
12-03-2012, 09:03 AM | #8 |
Accidentally in BMW
15
Rep 221
Posts |
Echo all above (CDV, cutch stop, trans mounts, etc.)
A high grade trans fluid is reported to help as well. The mods mentioned above are inexpensive and vital, in my opinion, to smooth shifting. I smiled ruefully when I recalled the jack-rabbiting and bunny-hopping that was common for me before I made the changes. Yes, both you and your passengers will wonder if you even know how to drive a stick until you address these things. This is probably the single major quirk of the Z4M. Also, experiment with the RPM for the sweet spot for 1-2 shifts. Unless you are short shifting (gently) to play with 2nd gear torque, you might find that the 1-2 shift happens more smoothly at a higher RPM than you are used to. This was my experience and I usually hold off until I'm above 5000 and even above 6000 for the smoothest shifts. Then engine seems to enjoy it too. |
Appreciate
0
|
12-03-2012, 09:47 AM | #9 |
Lieutenant
45
Rep 400
Posts |
I put a clutch stop in about 3 weeks ago. It makes an incredible difference with clutch travel. I installed it so that I didn't have to move the cutout switch. It really makes the clutch travel shorter and more consistent.
http://www.zpost.com/forums/showthre...ht=clutch+stop Last week, I installed RE tranny mounts. I didn't expect to feel any difference in shifting between gears. I was wrong. Even street driving, all gears engage more consistent now. You still have to be higher in revs for 1-2 shifting, but every other gear goes in just fine. I still have to install my Autosolutions SSK, which is supposed to tighten up the shifting even more. I'm waiting on parts to arrive. Oh yea, the CDV is a no brainer. Get rid of it next time your under your car. I got rid of mine a couple of months after I bought my car while I was flushing brake fluid. Also a weighted ZHP shift knob might help out, but no where near as much as the above changes. |
Appreciate
0
|
12-03-2012, 06:08 PM | #10 |
Private
11
Rep 81
Posts |
Well all of you were spot on with the higher rpm 1st and 2nd gear shifting. Today was the first day I tried it and it made a world of difference...not perfect but way better. During normal driving it didnt occur to me to try revving it up but the engine does feel like it enjoys it.
I was debating on flushing the brake/clutch fluid even though I only have 12k miles so if I do i'll pull the CDV during the process. I was also debating on changing the tranny fluid....the fluid changes would be because of being 5 years old not the 12k miles obviously. Waste of money? |
Appreciate
0
|
12-03-2012, 06:56 PM | #11 |
First Lieutenant
25
Rep 325
Posts |
If this is hijacking the thread, feel free to boot me. But can someone help me understand what the tranny mounts do to help this shift issue?
Also, I agree with revving higher in first or second gear before shifting. I took off quickly the other day and got it up to 6k or 7k and chirped the tires going into second gear. it spooked me a bit, but you REALLY take off in second gear this way. :-) |
Appreciate
0
|
12-03-2012, 07:10 PM | #12 |
Colonel
1226
Rep 2,935
Posts
Drives: Anything
Join Date: Apr 2010
Location: SoCal
|
See this post regarding transmission mount => http://www.zpost.com/forums/showthread.php?t=524589
|
Appreciate
0
|
12-03-2012, 07:45 PM | #13 | |
Lieutenant
45
Rep 400
Posts |
Quote:
The tranny flush is next on my list. I just need to do some research on which fluid to put back. Right now I'm leaning towards the OE fluid. I think fresh fluid can definitely make a difference since it lubes all the gears. |
|
Appreciate
0
|
12-04-2012, 05:47 AM | #14 |
Captain
153
Rep 688
Posts |
I to did this after I first got my M Coupe. Because of driving an E30 M3 with a light weight flywheel, the shifting was far different on the M Coupe. After a few weeks I finally realized that shifting from 1st to 2nd at rpm lower than 4500 was the biggest problem. If you watch the tach you will see the engine RPMs drop 2000 VERY quickly when you push the clutch in. I rev up to 5000 in first then shift to second. All other gears to at least 4500, the transmission just seems to like that better.
__________________
Lone Star Chapter BMWCCA HPDE Event Chair, Texas Trifecta Event Chair, & BMWCCA driving Instructor |
Appreciate
0
|
12-04-2012, 05:55 AM | #15 |
First Lieutenant
27
Rep 341
Posts |
For those changing the transmission oil, the drain plug is aluminum and super-soft, and easy to strip. Make sure you have a hex bit that fits properly, and maybe have a spare on hand.
__________________
|
Appreciate
0
|
12-04-2012, 07:09 AM | #16 |
Lieutenant General
2445
Rep 11,667
Posts |
plugs are one time use.
__________________
'21 M2C Hockenheim Silver
'18 718 Cayman S Lava Orange (sold) '13 E92 M3 Santorini Blue (sold) '07 Z4 M Coupe Alpine White (sold) |
Appreciate
0
|
12-04-2012, 11:38 AM | #17 | |
Dog Listener
711
Rep 7,850
Posts |
Quote:
The car seems to like higher revs just like you said, but with a very cold engine (and cold outside temps), I prefer to keep things a bit lower in the rev range for few minutes until the fluids have a chance to warm up a little bit. Just a personal "thing" I have with my cold warm up process. YMMD. |
|
Appreciate
0
|
12-04-2012, 04:08 PM | #18 | |
Major
159
Rep 1,108
Posts |
Quote:
Exactly! Don't let those rev's drop too much. I'll also add that using a faster gear shift movement works better for me too. Just because the rev's aren't high doesn't mean you can't shift quickly. |
|
Appreciate
0
|
12-04-2012, 04:44 PM | #19 |
tosser
32
Rep 988
Posts |
i didn't have time to read through the whole thread, but i had the same sentiments when i first got the car.
i changed the tranny fluid to royal purple synchromax and did the AS short shifter and changed back to oem shift knob. feel is fantastic for me not sure i'd even benefit from a cdv delete.
__________________
'07 MCoupe lots of mods |
Appreciate
0
|
12-04-2012, 06:18 PM | #20 | |
Colonel
190
Rep 2,138
Posts
Drives: Me
Join Date: Oct 2007
Location: Virginia Beach
|
Quote:
|
|
Appreciate
0
|
12-05-2012, 10:37 AM | #21 | |
First Lieutenant
75
Rep 392
Posts |
Quote:
I agree Shift faster = Smoother shifting Anyone else find that you can shift faster by moving the shifter gently trough the right path. whereas Pulling the shifter hard just causes it to grind more and delay your shift? |
|
Appreciate
0
|
12-05-2012, 11:05 AM | #22 |
Private
1
Rep 79
Posts |
..."so you either rev the engine while shifting or let the clutch half way and you'll feel when it engages"...
can you kill the clutch by shifting and accelerating at the same time? I have noticed this issue is even worse when the SPORT mode is initiated. My son's head is going back and forth and he keeps telling me I should learn how to drive manual trans even though I have been driving manual for the last twenty plus years. |
Appreciate
0
|
Post Reply |
Bookmarks |
|
|