[nsjames]

am I the only one that doesn't loathe the GM box?

It works fine.
it downshifts when I want, mostly, and does it's job.
my only complaint is it's tendency to lug the motor up a hill and then make a panicked downshift when the cruise control is on. I'm sure that's mostly emissions programming.

I did flash the 330ish calibration that hass came up with before there were problems, but I don't really recall hating it prior.

Your thoughts on yours, service history?
Mine got new dex 6 at 103K miles and a filter.
Serviced again at 160K with max life. I can't say I really can tell a difference.
Still doing transmission things at 175K.

I do have SAT, so maybe paddles changes the experience? I do tend to grab a lower gear with the paddle before attempting any overtaking, but if I'm driving sporty I just leave it in DS and let it manage itself.
I rarely use manual mode, even after nelson racing paddles and all that.


everyone seems to universally hate it, and I agree that it's no ZF, but it's far from the worst automatic i've ever had the displeasure of using, I suspect most of the hate is simply because we're generally second owners and they were neglected previously.

yes, if it dies I'll replace it with a manual, but if serviced properly I have no reason to believe I'll be doing that work.

[sonofsun]

Pre torque converter shudder this transmission was awesome. I liked the way it shifted and stuff. Once the shudder started showing up I had to change the fluid, filter and it still didn't fix the shudder. Added the Lubegard magic shudderfixx and it fixed the shudder right up.

I guess BMW is deliberately messing up these transmissions by not recommending a drain and replace of ATF every 30,000 miles or so. If I get a different BMW I will make sure the ATF and other maintenance are done ignoring BMW's service interval guidelines.

[nsjames]

Originally Posted by sonofsun

Pre torque converter shudder this transmission was awesome. I liked the way it shifted and stuff. Once the shudder started showing up I had to change the fluid, filter and it still didn't fix the shudder. Added the Lubegard magic shudderfixx and it fixed the shudder right up.

I guess BMW is deliberately messing up these transmissions by not recommending a drain and replace of ATF every 30,000 miles or so. If I get a different BMW I will make sure the ATF and other maintenance are done ignoring BMW's service interval guidelines.

GM cars with this exact transmission recommend 50K mile service for "severe use" and 100K mile service for normal use.

at 60K miles the fluid I drained out looked OK.
The 103K mile change it was brown and oxidized.
Somewhere in the 60-70K range is probably where most people need to service it.

[gjm120]

I don't dislike mine one bit. Yeah, sometimes wish I got a manual, but, never enough to do anything about it.

For driving around town it shifts up and down pretty much where I would have shifted a manual. I also use the paddles a good bit, even when in non-sport mode.

When in DS and manual mode, shifts are fairly quick at higher rpm's. Pretty "relaxed" shifting at lower rpms, but so what.

Fluid / filter change at just under 50k miles. Shifts got crisper. I didn't do any adaptation reset since everything was working fine.

[sonofsun]

I also didn't reset my adaptations. Not sure why so many other people recommend it though. I've heard horror story of people wrecking their transmission doing an adaptation reset.

[e90yyc]

Despite the hyperbole, I don’t think it’s all bad. And putting aside the fact that being a GM product makes it more fun to bitch about, my true feelings about it are based on my experience with it and not the manufacturer’s name.

To recap what I said in another thread, it’s difficult to service certain parts of it without either spending major dollars or pulling the unit. And of course in my case, it shifts like dogshit.

I tend to judge long-lived products in two ways: How does it perform when it’s new and/or operating correctly? In this case, likely quite well. And then, how does it perform as it ages, and how easy and cost effective is it to maintain its performance and to repair?

It’s the second point that I take issue with. And I’d say the same thing about a lot of products that are a dream to own when they’re working well but can be a giant thorn in the balls when things start to go wrong.

I’m sure the hard parts are solid enough and that it has some virtues despite the hate it gets. I just wish I could easily replace shift solenoids and service (replace) the PR valve without having to either spend an absurd amount of money, or spend an absurd amount of time to drop the tranny to replace a $10 part.

Just my $0.02. As usual, I’m probably wrong

[ryan stewart]

Mine is fine save for two things:

1. When its ice cold (aka winter garage and having just started up) it will delay shifting up to second. Not sure if intentional or just because fluid is cold. But literally a block down the road its done, shifts normally after that.

2. A very rare hard downshift, usually after accelleration and then braking. Like I was accelerating onto a road and then got cut off, so it gets confused when I get back on the throttle.

At 100k I did the service but I also dropped the mechatronics, drained it, and replaced the seals between the valve body and the planetary set. It was shifting hard before that. Nothing horrid but noticeable. Been fine since. Not sure if it was the fresh fluid alone or that changing the mech seals to the planetary but the original ones were very hard and compressed, felt more like plastic than rubber compared to the new ones.

Oh and I did do the sonnax valve thing since in my searches it sounds like that valve head can pop off, leaving you stuck in park, neutral or drive. One of the nice things about it being a caddy transmission is there is a big aftermarket for it.

[ryan stewart]

Originally Posted by sonofsun

I also didn't reset my adaptations. Not sure why so many other people recommend it though. I've heard horror story of people wrecking their transmission doing an adaptation reset.

Just like how we all have heard horror stories about how people changed their tranny fluid and it got their wife pregnant by another mans child.

I doubt resetting the adaptations is going to destroy the transmission.

[ryan stewart]

Originally Posted by nsjames

GM cars with this exact transmission recommend 50K mile service for "severe use" and 100K mile service for normal use.

at 60K miles the fluid I drained out looked OK.
The 103K mile change it was brown and oxidized.
Somewhere in the 60-70K range is probably where most people need to service it.

Concur. Mine has lived an easy life. I did my service before I started towing and mine is just a stock N52k wagon that has had a very easy life (simple commute shared with motorcycles, occasional road trip, rarely gets past 3000rpm) and my fluid at 100k was what I would consider "medium well."

Id say if youre driving aggressively and/or in an extreme climate go ahead and creep towards that 50k and dont pass 100k.

[dmatre]

I can't say that I hate mine, I just wish the shifts were quicker at WOT.

It's smooth around town, in SPORT it hangs the revs a bit too long before shifting, but I've got paddles which let me work around that.

No, it's not as crisp as the ZF - but it's not horrible.

Because the TC locks up early, I find that those who treat the throttle as an On/Off switch tend to have more problems than those who can differentiate between 37% throttle and 37.5% throttle.

My wife drives with a yo-yo foot: "throttle on, throttle off/coast" and she doesn't like to drive my car.

[E92_William]

If you have the 3.0si software it is A LOT better when it comes to DS and specially manual mode. I drive mine in manual mode all the time because the converter lock up makes it feel so direct it's the closest thing to a manual you can get with this transmission. I regularly have to press it over 50% throttle to get it to downshift while cruising at 60 on the highway. On the stock calibration it has a ridiculous tendency to want to lug the engine in D which isn't upgraded much with the 3.0si file. Imo these are all tuning problems, until someone manages to get the key for the software this is as good as it's gonna get. Now recently it has decided it wants to be jerky at low speeds when getting on and off the gas still wouldn't swap to a manual unless it completely broke

If you want to see a bad GM transmission go drive an E46 with the 5L40... the torque converter NEVER locks up in manual mode, it's one of those transmissions that you shift into a gear in manual and it goes to say 2500 rpm but you get on the gas and it unlocks the converter and allows slip to 3000... making it feel sluggish as shit like a cvt. We have it easy.

[American Cincinnatus]

I've got a (4000lb) E93 328i, so I justify having an auto as a "low and slow cruiser". I had my first car, a 1986 318i, concerted to a manual, and it was one of the better decisions I ever made. I love manuals. I do wish my car was a manual. But auto is ok. At 108k miles now, did a tranny flush at around 97k. Hope that holds it over. Wish it was german made. That's about it

[rothwem]

Originally Posted by E92_William

If you want to see a bad GM transmission go drive an E46 with the 5L40... the torque converter NEVER locks up in manual mode, it's one of those transmissions that you shift into a gear in manual and it goes to say 2500 rpm but you get on the gas and it unlocks the converter and allows slip to 3000... making it feel sluggish as shit like a cvt. We have it easy.

I had a 5L40 in my X3, I didn't think it was too bad in automatic mode, but yeah, the manual mode was painful. I think its because it didn't rev-match the downshifts, it just unlocked the TC and allowed it to spin to absorb the shift. This resulted in some SERIOUS heat when driving on twisty, hilly roads. I obviously never took my X3 to a track day, but I imagine that it wouldn't go so well

With that said, it was super smooth in daily driving, and did great in stop and go traffic. I also thought the "sport mode" shift logic was better in the X3 than in my current E91.

[tlow98]

This transmission has served our family well in two different cars.

My biggest issue: BMW purposefully neutered the tuning to widen the product gap between this and the 335i. Either that, or bc this was the US ‘economy’ car and they did it for MPG. Either way, it never makes the ‘fun’ gear choice when in D.

In Sport, it’s fine, but doesn’t go into top gear which I also find slightly annoying. IMO, the sport setting should have full use of every gear and make the decision based on what the most fun outcome would be given some level of reason.

I’m only frustrated, bc I feel like BMW knew what could be done and held it back on purpose. The Germans love playing that game.

Back to the positives. It’s a tank! I changed the fluid/filter @ 65k and fluid @100k in one unit. All was well. In the other unit I changed the fluid @85k. All was well, tho definitely more oxidized and dark than the more frequently changed unit.

Also, I kind of like the fact that it’s a GM trans. Lots of serviceability and, in general, GM units are very solid. The shortcomings are not hardware related at all from what I can see. All about the economy minded tuning that doesn’t really allow the great N52 to show off its best. The N52 is much better than the transmission tuning suggests!

Long love the manual, but also I have no beef with this GM unit.

[Leucosticte]

My transmission was trash before fluid change + 3.0si flash, it was jerky and had tons of torque convertor shudder.

After the first fluid change it was better, but what really made a difference was the 3.0si flash, it felt like a different car and the shifts felt much more crisp. Unfortunately the torque converter shudder came back, so about a month ago I changed the fluid for the second time, and that made the transmission even smoother and made the torque converter shudder go away. Right now I'm pretty happy with it, although a manual really tempts me sometimes, I'd love to have one instead of an auto.

D - Good for cruising + highway driving, I wish it was more eager to downshift but it got better after the 3.0si flash.
DS - Holds gears aggressively which I like.
Manual mode - Feels good although there's probably a half second delay between when you tell it to shift and it actually shifting, the torque converter is locked up pretty much all the time in this mode which feels pretty good.

Overall compared to the zf in my friends 330i the gm holds gears a lot more which I like and after the 3.0si flash I would say it is overall better. Although it would probably be a different story if he got XHP.

[M-technik-3]

It's ok, not fantastic but for the price of the car I don't understand why BMW opted away from the ZF since other 3 series got them.

[tlow98]

Originally Posted by Leucosticte

My transmission was trash before fluid change + 3.0si flash, it was jerky and had tons of torque convertor shudder.

After the first fluid change it was better, but what really made a difference was the 3.0si flash, it felt like a different car and the shifts felt much more crisp. Unfortunately the torque converter shudder came back, so about a month ago I changed the fluid for the second time, and that made the transmission even smoother and made the torque converter shudder go away. Right now I'm pretty happy with it, although a manual really tempts me sometimes, I'd love to have one instead of an auto.

D - Good for cruising + highway driving, I wish it was more eager to downshift but it got better after the 3.0si flash.
DS - Holds gears aggressively which I like.
Manual mode - Feels good although there's probably a half second delay between when you tell it to shift and it actually shifting, the torque converter is locked up pretty much all the time in this mode which feels pretty good.

Overall compared to the zf in my friends 330i the gm holds gears a lot more which I like and after the 3.0si flash I would say it is overall better. Although it would probably be a different story if he got XHP.

Did you try the anti shudder fluid pack that is made for this specific purpose? It’s a very small amount of fluid but many have had great success with it. I forget the name but easy to find with a search.

[Mark963]

I looked around for a while and drove a few different E90 328's with 40-80k miles. Before that, I'd driven an E46 and kicked myself for putting up with a Toyota for too long, but the E90 seemed very Toyota like. One of the awful traits that 2 of the 3 had was they couldn't keep up with traffic taking off at every stop light. Cars would roll away slowly and the E90 would slowly take off and instantly get up to ~4th gear and as the cars in front of would continue to accelerate, I'd stop down more and more until it might abruptly shift down to 2nd and take off then I'd catch up and it would fly into higher gear... It was nuts. I drove each car for a couple hours and couldn't believe what they were like.

A friend owned a Z3, a couple 328's and a one-series and he told me I was nuts. They were all manual transmissions. Then he bought one of the cars I looked at, got it home and went "holy crap this is terrible".

I sort of learned to "work" the accelerator, but it never felt right and it was hard to make the car do what I wanted as far as acceleration. I tried doing the hold down the accelerator with the engine off - reset the adaptations - a little better for a while.

Then I took the car in for a recall and asked what it cost to update all of the firmware. That had greatly improved a low-temp issue I had in different car with a 6 speed transmission, so I figured it couldn't hurt and the car had all original firmware in it. So for two-hours of labor, they updated everything but the radio stuff because apparently that causes issues sometimes. Initially, it would sometimes flip down and then back a gear and was hugely ready to shift any time, but that calmed down after a few days. It was like a different car. My friend had the same done to his and confirmed that it was a huge improvement.

Recently, at 50K miles, I swapped out most of the transmission fluid - 3 gallons (Valvoline Multi-Vehicle Full Synthetic) went through it. The original fluid was very opaque and muddy brown, but the Blackstone report came back good with just somewhat high iron/aluminum from break in. I think that has improved the shifting a bit more, but maybe it's just in my head or maybe it was temporary as it adjusted to the new fluid.

At this point, I find the 6L45 downshifts readily when going >35mph which it didn't like to before. I'd read that a jab of accelerator was supposed to induce an immediate down shift, but it didn't work. Now it does. A quick jab will down shift and then return if you take your foot back all the way to where it was. Jab and then hold it further down WILL downshift and you're off. But at 15-20mph around a slow corner, it still doesn't like to downshift to second consistently or as willingly as I'd like. I want to accelerate through the corner and it almost pulls it off just a bit late, most of the time. But I still think about "if I could change the programming...."

So I believe these GM transmissions will exhibit greatly varying performance. From everything I've read, I think they're more reliable than the ZF's, where the ZFs' frequently need new gaskets at 80-100K and the GM doesn't.

[nsjames]

Originally Posted by tlow98

Did you try the anti shudder fluid pack that is made for this specific purpose? It’s a very small amount of fluid but many have had great success with it. I forget the name but easy to find with a search.

lube guard

mine had a shudder when I bought it, but has never come back after servicing.

[Leucosticte]

Originally Posted by tlow98

Did you try the anti shudder fluid pack that is made for this specific purpose? It’s a very small amount of fluid but many have had great success with it. I forget the name but easy to find with a search.

If it comes back I will.

[CTinline-six]

Originally Posted by Mark963

I looked around for a while and drove a few different E90 328's with 40-80k miles. Before that, I'd driven an E46 and kicked myself for putting up with a Toyota for too long, but the E90 seemed very Toyota like. One of the awful traits that 2 of the 3 had was they couldn't keep up with traffic taking off at every stop light. Cars would roll away slowly and the E90 would slowly take off and instantly get up to ~4th gear and as the cars in front of would continue to accelerate, I'd stop down more and more until it might abruptly shift down to 2nd and take off then I'd catch up and it would fly into higher gear... It was nuts. I drove each car for a couple hours and couldn't believe what they were like.

A friend owned a Z3, a couple 328's and a one-series and he told me I was nuts. They were all manual transmissions. Then he bought one of the cars I looked at, got it home and went "holy crap this is terrible".

I sort of learned to "work" the accelerator, but it never felt right and it was hard to make the car do what I wanted as far as acceleration. I tried doing the hold down the accelerator with the engine off - reset the adaptations - a little better for a while.

Then I took the car in for a recall and asked what it cost to update all of the firmware. That had greatly improved a low-temp issue I had in different car with a 6 speed transmission, so I figured it couldn't hurt and the car had all original firmware in it. So for two-hours of labor, they updated everything but the radio stuff because apparently that causes issues sometimes. Initially, it would sometimes flip down and then back a gear and was hugely ready to shift any time, but that calmed down after a few days. It was like a different car. My friend had the same done to his and confirmed that it was a huge improvement.

Recently, at 50K miles, I swapped out most of the transmission fluid - 3 gallons (Valvoline Multi-Vehicle Full Synthetic) went through it. The original fluid was very opaque and muddy brown, but the Blackstone report came back good with just somewhat high iron/aluminum from break in. I think that has improved the shifting a bit more, but maybe it's just in my head or maybe it was temporary as it adjusted to the new fluid.

At this point, I find the 6L45 downshifts readily when going >35mph which it didn't like to before. I'd read that a jab of accelerator was supposed to induce an immediate down shift, but it didn't work. Now it does. A quick jab will down shift and then return if you take your foot back all the way to where it was. Jab and then hold it further down WILL downshift and you're off. But at 15-20mph around a slow corner, it still doesn't like to downshift to second consistently or as willingly as I'd like. I want to accelerate through the corner and it almost pulls it off just a bit late, most of the time. But I still think about "if I could change the programming...."

So I believe these GM transmissions will exhibit greatly varying performance. From everything I've read, I think they're more reliable than the ZF's, where the ZFs' frequently need new gaskets at 80-100K and the GM doesn't.

I own a 2009 328i with the 6L45. Bought it with 32,000 miles and it now has 78,000. I originally wanted a manual RWD N52 powered car, but settled for this low mileage auto, since finding a RWD car was hard enough after almost a year of searching.

This transmission definitely has it's moments, odd shifts where it gets confused, etc, but there are a few things that I've noticed help with the drivability.

1. When just cruising along casually, use D. If you want to have fun down a nice curvy road drive in DS or use manual mode. Trying to drive spiritedly in "D" will confuse the transmission as you will try to give it more throttle in order to downshift. This lazy throttle response programming in D is definitely for economy.

2. With all that in mind, it definitely adapts to how you drive, and I find that if I do quicker starts from a stop light consistently (not full or even 3/4 throttle, but slightly quicker than it's normal lazy self) it will adjust and seem to respond better after 1000 miles or so.

3. I change the fluid every 40k miles with MaxLife synthetic, which has improved the shifting.

4. I've added a Euro air box, and a silicone intake boot, which definitely improved the throttle response off the line. I seriously doubt there were any power gains, but that initial dead spot when accelerating from a stop has been greatly reduced.

5. The lag mentioned in #4 is even greater with XDrive cars. I've driven them back to back as two friends own 328 E9x XDrive cars and you can definitely notice more lag.

6. When downshifting to pass, make sure you press the gas all the way to the floor until you feel that little 'click'. With the car off, if you press the gas all the way down, you can feel a click at the bottom, this allows the car to kick down the transmission to pass. If you simply push the pedal most of the way down, you might drop just 1 gear instead of 2.

[nsjames]

Originally Posted by CTinline-six

I own a 2009 328i with the 6L45. Bought it with 32,000 miles and it now has 78,000. I originally wanted a manual RWD N52 powered car, but settled for this low mileage auto, since finding a RWD car was hard enough after almost a year of searching.

This transmission definitely has it's moments, odd shifts where it gets confused, etc, but there are a few things that I've noticed help with the drivability.

1. When just cruising along casually, use D. If you want to have fun down a nice curvy road drive in DS or use manual mode. Trying to drive spiritedly in "D" will confuse the transmission as you will try to give it more throttle in order to downshift. This lazy throttle response programming in D is definitely for economy.

2. With all that in mind, it definitely adapts to how you drive, and I find that if I do quicker starts from a stop light consistently (not full or even 3/4 throttle, but slightly quicker than it's normal lazy self) it will adjust and seem to respond better after 1000 miles or so.

3. I change the fluid every 40k miles with MaxLife synthetic, which has improved the shifting.

4. I've added a Euro air box, and a silicone intake boot, which definitely improved the throttle response off the line. I seriously doubt there were any power gains, but that initial dead spot when accelerating from a stop has been greatly reduced.

5. The lag mentioned in #4 is even greater with XDrive cars. I've driven them back to back as two friends own 328 E9x XDrive cars and you can definitely notice more lag.

6. When downshifting to pass, make sure you press the gas all the way to the floor until you feel that little 'click'. With the car off, if you press the gas all the way down, you can feel a click at the bottom, this allows the car to kick down the transmission to pass. If you simply push the pedal most of the way down, you might drop just 1 gear instead of 2.

I found all of the low end disappointment was corrected with the DISA manifold.
no longer did I find myself revving it to 4-5K RPM to just get out of it's own way. Suddenly 2500-3500rpm is completely usable.

There were definitely things BMW did to intentionally widen the gap in performance between 328s and the new flagship 335.

I do wish we could play with the trans programming. There's a lot more potential in the box, but that's probably never gonna happen.