[Al Bundy's Dodge]

Originally Posted by TheObviousChild

Ha! Yes, I completely understand how this makes me look. For the record, this is my 6th MT 3 Series since my original 2004 325i. I have never had any issues until this 2016 340 6MT. I'd like to think I'm not the problem here. I definitely drive it hard, but no harder than a BMW is designed to be driven.

If there is a flaw with the design, as it appears to be, I think BMW is just blindly swapping a transmission with another flawed unit. The last time, they didn't even bother investigating. Said, "bad synchro" and sent it back to Germany and threw in another.

My 2015 6MT gearbox is smooth as silk. One of the reasons I enjoy the car so much. That said, the car we test drove prior to this one had a 6MT as well. It felt like a grind going from 1st to 2nd so we didn't even bother with an offer.

My old e90 was known to have less than smooth shifts on occasion but it was usually when it was cold outside. She was over 9 years old when I traded her in and never ended up having an issue with the transmission.

Good luck to ya

[TheObviousChild]

Originally Posted by Al Bundy's Dodge

My 2015 6MT gearbox is smooth as silk. One of the reasons I enjoy the car so much. That said, the car we test drove prior to this one had a 6MT as well. It felt like a grind going from 1st to 2nd so we didn't even bother with an offer.

My old e90 was known to have less than smooth shifts on occasion but it was usually when it was cold outside. She was over 9 years old when I traded her in and never ended up having an issue with the transmission.

Good luck to ya

Thanks Denver buddy! I've gone to Gebhardt in the past as I lived up north, but I'm down south now so will be taking it in to Schomp. Fingers crossed.

[B58 parts]

That sucks .. maybe it's just bad luck.

This gearbox is really slow, a redline 1->2 shift requires some patience .. it just seems natural to wait for it as there's a bit of resistance in the lever until it catches up. I feel if I forced it down, it would probably grind as I used to do with the old Honda. I don't know what it is with this one but I've yet to catch a single bad noise around town. With the Subaru, low speed around town I'd clunk up 2nd or 1st way more than I care to admit.

I do have occasions where 3rd or 4th won't go in first try at low speeds. Cold ambient/mechanical temps are usually there but not always. I can't figure that out yet. I can feel something moving around downstream that blocks the lever out. Tech obviously could not reproduce the problem. It may just be me going into the gate a bit off.

Do you keep your hand on the shifter? Do you have one of those clutch stops? I removed mine .. it didn't really make it all that better, and was just a different thing to get used to. I doubt the computer match or lack thereof has anything to do with an upshift grind, but you should disable that on principle.

Perhaps they didn't fill the replacement up enough.

[Kaps335i]

Originally Posted by TheObviousChild

2016 340 xDrive with about 21,000 miles on it. I've already had the 6MT swapped once due to the 2nd gear synchro.

Now 3rd is grinding on shift. Preparing to have to give up my car for another few days while they replace the transmission again.

Why is this manual transmission so flaky?

Originally Posted by TheObviousChild

2016 340 xDrive with about 21,000 miles on it. I've already had the 6MT swapped once due to the 2nd gear synchro.

Now 3rd is grinding on shift. Preparing to have to give up my car for another few days while they replace the transmission again.

Why is this manual transmission so flaky?

I had mine replaced at 24k due to 2nd gear grind. I used to shift hard. Now I don't. I wonder if these transmissions just can't take the abuse...

[Rob340i]

I have had my 340 for 2 months i have driven only manuals for 15 years the second gear shift going in and going to third causes the car to jerk a little like a missed shift especially if you get over 5k rpms. This makes me nervous about the 2nd gear

[eluded]

Originally Posted by uncleruckus

Do you normally drive with the rev match feature enabled or disabled ?

I remember in past threads of F30 manual transmission issues, people were theorizing that having auto rev match might alleviate some of the synchro wear issues.

I thought you would have to be double clutching to avoid the synchronization wear ? I've played with the rev matching going way down in gears and I swear I feel resistance when rev match shifting versus when I double clutch and rev match myself as God intended.

I pretty much double down all the time so the rev matching never works. If you plip the throttle at all between the shifts it does not kick in.

I also see the Second gear grind but when I actually take the time to concentrate on redline shifts and wait that split-second it doesn't seem to grind… Will keep an eye on it

[TheObviousChild]

I have an update:

Took it in this morning. Just got the (expected) call confirming the transmission needs to be swapped. It is going to take 10-14 days to get here from Germany. The SA assures me he's been there for 20 years and has rarely seen this. I told him I'm nervous as I've now seen this twice and several more times on the forums. This is the first Bimmer of the 6 I've had that I've bought and not leased so I'm a bit worried about it failing again. He told me it would be $14,000 to replace out of pocket. That blew my mind.

As soon as the G80 gets opened for orders, I'm jumping. In the meantime, I'll try to enjoy the....X1 they loaned me.

[Al Bundy's Dodge]

Originally Posted by TheObviousChild

I have an update:

Took it in this morning. Just got the (expected) call confirming the transmission needs to be swapped. It is going to take 10-14 days to get here from Germany. The SA assures me he's been there for 20 years and has rarely seen this. I told him I'm nervous as I've now seen this twice and several more times on the forums. This is the first Bimmer of the 6 I've had that I've bought and not leased so I'm a bit worried about it failing again. He told me it would be $14,000 to replace out of pocket. That blew my mind.

As soon as the G80 gets opened for orders, I'm jumping. In the meantime, I'll try to enjoy the....X1 they loaned me.

Did you get the "bad synchro" explanation from Schomp? Or something else?

Sorry you're going through this, really disappointing to hear. Have always thought the BMW gearboxes were "bulletproof".

[XutvJet]

Originally Posted by TheObviousChild

I have an update:

Took it in this morning. Just got the (expected) call confirming the transmission needs to be swapped. It is going to take 10-14 days to get here from Germany. The SA assures me he's been there for 20 years and has rarely seen this. I told him I'm nervous as I've now seen this twice and several more times on the forums. This is the first Bimmer of the 6 I've had that I've bought and not leased so I'm a bit worried about it failing again. He told me it would be $14,000 to replace out of pocket. That blew my mind.

As soon as the G80 gets opened for orders, I'm jumping. In the meantime, I'll try to enjoy the....X1 they loaned me.

These prices are hilarious. You can buy a new "remanufactured" (can't buy a brand new one) ZF 6MT for around $3,500-3,800 from one of the many online BMW parts shops. Book time to swap the 6MT only (no clutch/flywheel) replacement is around 5 hours or $700. So, on your own dime, a replacement 6MT should cost around $5,000 with tax, not $14,000. LOL

Now if you have a 8AT, well, that is quite pricey. You're looking at around $12,000-13,000 to swap in a re-manufactured one. Maybe that's where they got the $14,000 number.

[XutvJet]

Originally Posted by Al Bundy's Dodge

Did you get the "bad synchro" explanation from Schomp? Or something else?

Sorry you're going through this, really disappointing to hear. Have always thought the BMW gearboxes were "bulletproof".

The AWD traction puts a hell a strain on the syncros if you're beating on it hard. The RWD is a bit softer on the 6MT because there is wheel spin on launch and on the 1-2, but you can still wreck the syncro if you're banging the 1-2 often, especially if you've got power mods which will add a TON MORE torque in 1st and 2nd at the gear.

The ZF GS6-45BZ tranny is stout and has been around for quite some time. The F series cars use this tranny and it's the same one used in the 1M except that the tranny was revised to have a stronger 1-2 syncros in the F series. The M2-M4 use the same tranny as well except the syncros are beefed up even more in the first 3 gears.

If you own a 6MT, I think it's best you not slam the 1-2 shift unless you really need to and if you do, make sure the tranny fluid is warm (20 minutes of driving). With AWD and power mods, you're really walking on egg shells.

[TheObviousChild]

Originally Posted by XutvJet

The AWD traction puts a hell a strain on the syncros if you're beating on it hard. The RWD is a bit softer on the 6MT because there is wheel spin on launch and on the 1-2, but you can still wreck the syncro if you're banging the 1-2 often, especially if you've got power mods which will add a TON MORE torque in 1st and 2nd at the gear.

The ZF GS6-45BZ tranny is stout and has been around for quite some time. The F series cars use this tranny and it's the same one used in the 1M except that the tranny was revised to have a stronger 1-2 syncros in the F series. The M2-M4 use the same tranny as well except the syncros are beefed up even more in the first 3 gears.

If you own a 6MT, I think it's best you not slam the 1-2 shift unless you really need to and if you do, make sure the tranny fluid is warm (20 minutes of driving). With AWD and power mods, you're really walking on egg shells.

That really explains a lot. I do not go easy on this car, but drive it like a friggin BMW is meant to be driven. 340 PLUS the added power from MPPSK PLUS AWD....

I don't want a BMW I have to drive delicately. I'm going to get a friggin M3 already.

[Al Bundy's Dodge]

Originally Posted by XutvJet

The AWD traction puts a hell a strain on the syncros if you're beating on it hard. The RWD is a bit softer on the 6MT because there is wheel spin on launch and on the 1-2, but you can still wreck the syncro if you're banging the 1-2 often, especially if you've got power mods which will add a TON MORE torque in 1st and 2nd at the gear.

The ZF GS6-45BZ tranny is stout and has been around for quite some time. The F series cars use this tranny and it's the same one used in the 1M except that the tranny was revised to have a stronger 1-2 syncros in the F series. The M2-M4 use the same tranny as well except the syncros are beefed up even more in the first 3 gears.

If you own a 6MT, I think it's best you not slam the 1-2 shift unless you really need to and if you do, make sure the tranny fluid is warm (20 minutes of driving). With AWD and power mods, you're really walking on egg shells.

MAkes sense...I commented in another thread that my previous 2 MTs always shifted best from 1 > 2 at low RPMs...like around 2500. And I often end up just starting in 2nd gear anyway with all of the rolling stops I do....so slamming 1 to 2 is rarity for me, and maybe that's partly why Ive never had an issue with my gearboxes.

[XutvJet]

Originally Posted by TheObviousChild

That really explains a lot. I do not go easy on this car, but drive it like a friggin BMW is meant to be driven. 340 PLUS the added power from MPPSK PLUS AWD....

I don't want a BMW I have to drive delicately. I'm going to get a friggin M3 already.

I don't know of many manual cars, especially AWD, that can take a heavy flogging on the 1-2 when pushing serious torque. The torque multiplication in 1st and 2nd is really high and adding mods only compounds the issue. Vipers, F Bodies, Stangs, Vettes, WRXs, EVOs, turbo BMWs, Porsches, etc. all tend to suffer from bad 1-2 syncros if you beat on often. I've read numerous articles about the M2 where they note a very audible crunch on the 1-2 (probably the same test car at the time). The 1M had lots of reported 1-2 syncro issues as well and there are reports of the issue in the M3 and M4 cars as well. Unfortunately, that 1-2 syncro is the weak link in the 6MT. Otherwise it's incredibly stout and is why people pushing massive power through their turbo BMWs go with the 6MT as the DCT and 8AT won't survive.

Many say they want to drive their BMW the way it was meant to be driven. Thing is, true sports driving doesn't really involve slam shifting the gears and in most all road race situations, you're not in 1st thus no need to hit the 1-2 hard. Only in drag racing would you grab 2nd hard assuming you're going for the best ET possible.

What I like about the manual is that you are in control of the shift speed. I love winding it out, slow shift, and continue to wind it out. Is it the fastest way to accelerate? Nope, but it feels and sounds great. Torque shock on shifts is great too as it add drama to the driving experience. With the auto, it's always grabbing the next gear as fast as possible and it does it so well that it often feels CVT-like in nature. Fast and quick, for sure, but boring after a while. Been there, did that.

[TheObviousChild]

Originally Posted by XutvJet

I don't know of many manual cars, especially AWD, that can take a heavy flogging on the 1-2 when pushing serious torque. The torque multiplication in 1st and 2nd is really high and adding mods only compounds the issue. Vipers, F Bodies, Stangs, Vettes, WRXs, EVOs, turbo BMWs, Porsches, etc. all tend to suffer from bad 1-2 syncros if you beat on often. I've read numerous articles about the M2 where they note a very audible crunch on the 1-2 (probably the same test car at the time). The 1M had lots of reported 1-2 syncro issues as well and there are reports of the issue in the M3 and M4 cars as well. Unfortunately, that 1-2 syncro is the weak link in the 6MT. Otherwise it's incredibly stout and is why people pushing massive power through their turbo BMWs go with the 6MT as the DCT and 8AT won't survive.

Many say they want to drive their BMW the way it was meant to be driven. Thing is, true sports driving doesn't really involve slam shifting the gears and in most all road race situations, you're not in 1st thus no need to hit the 1-2 hard. Only in drag racing would you grab 2nd hard assuming you're going for the best ET possible.

What I like about the manual is that you are in control of the shift speed. I love winding it out, slow shift, and continue to wind it out. Is it the fastest way to accelerate? Nope, but it feels and sounds great. Torque shock on shifts is great too as it add drama to the driving experience. With the auto, it's always grabbing the next gear as fast as possible and it does it so well that it often feels CVT-like in nature. Fast and quick, for sure, but boring after a while. Been there, did that.

Ok, So in daily driving, I shoudl get in the habit of pulling to higher rpms, clutch-in, shift, ease into the next gear....rather than popping the clutch out and slamming the pedal down? I can do that.

The problem seems to revolve around torque, so I would imagine there is no added risk/damage when down-shifting. On my 335 I would rev-match (which was fun), but now they have the auto rev-matching. I frequently downshift. Hoping I'm not doing any damage. This seems so silly to even type. You would think a car like this could handle it.