[Leucosticte]

My car is an 07 E92 328xi, I changed the transmission fluid 1k miles ago at 134k miles because I was unsure of whether the transmission had ever been serviced before, and also because I had the famous torque converter shudder that occurs at high load and low rpms. After the fluid change, the shudder went away and the car drove great. However, after driving it hard, I'm very disappointed to say that this shudder has returned. I don't know if this is a sign that I would need to replace the torque converter itself. Is it possible that driving it hard has caused the fluid to pick up some old sediments? Should I try changing the fluid again and go from there? Or should I take it to a local Euro shop and see what they have to say?

EDIT: I would also like to add that the transmission drove without any form of shudder for the last 1k miles or so, it has returned in the past 100 miles.

[tlow98]

There is an additive for this trans. Get 2 of the 100ml packets. Many have reported excellent success with this. Search on here for line guard instant shudder fix.

[E92William]

There's the additive which you can use like he said^. I've had great luck with just a fluid change and no additive but you can do both if you want. I remember when I didn't know what it was I thought the engine was lugging or something lol.

[Leucosticte]

thoughts about changing the fluid, refreshing all the mechatronic and valve body seals, and adding the additive?

[nsjames]

how did you change the fluid?

multiple drain and refills?
If you only did it once it's still 50% old fluid.
changed the filter?

I would service it again and put in the lube guard before I committed to taking apart it's valve body.
and if it is valve body it's probably not seals. It's probably worn out bores. sonnax has a kit, but honestly just buy a reman valve body for a few hundred bucks more and save yourself the headache.

[Leucosticte]

I did one drain and fill, I doubt the valve body is the issue that's causing shudder I just want to refresh all the seals as a "while you're there" thing.

[nsjames]

Originally Posted by kakapo

I did one drain and fill, I doubt the valve body is the issue that's causing shudder I just want to refresh all the seals as a "while you're there" thing.

so what you need to do is drop the pan and service the filter.
only replace the filter to VB seal.

at that point you'll have 80% + new fluid and a new filter in it.
put in the additive if you want.

if you really want to replace seals.
https://www.sonnax.com/parts/3525-ce...pport-seal-kit

that's the actual solution for a slipping clutch apply in 6th from a leak from the VB into the case passages.

here's valvebody removal and instructins.
https://d2q1ebiag300ih.cloudfront.ne...f?v=1548773279

but I wouldn't. that's a can of worms that you don't open unless you know there's a problem.

I would service it properly and then see.

[Leucosticte]

Thats weird, the seals that you linked are different than the one that I was thinking about. Here are the links to the ones I was thinking about replacing:

https://www.fcpeuro.com/products/bmw...98#description

https://www.fcpeuro.com/products/bmw...ve-24157572607

[nsjames]

because that's the fix for those ones that suck in the top left corner of that fcp page.
sonnax is an aftermarket company that makes parts that fix common transmission issues.

[E92William]

I think and hope that you're overthinking it. I'd just do another change with the additive like nsjames suggested. Depending how bad the shudder is it can take a couple fluid changes. On my 128i as soon as i changed it it went away. The GM box doesn't destroy valve body seals nearly as often as the 6hp does.

[Leucosticte]

I just hope that the torque converter isn't damaged, I would be so surprised if it was at 135k miles especially since I've seen people drive this auto over 250k. I don't feel like replacing it and might as well go for a 6mt swap if its something I need to do. I'll try a fluid and filter change with the additive after my summer classes are over and see if that helps.

[tlow98]

Originally Posted by E92William

I think and hope that you're overthinking it. I'd just do another change with the additive like nsjames suggested. Depending how bad the shudder is it can take a couple fluid changes. On my 128i as soon as i changed it it went away. The GM box doesn't destroy valve body seals nearly as often as the 6hp does.

Agree with this plus everything nsjames says. Don’t overthink it. Just swap fluid again plus put the additive in.

[bmwbob89]

My new to me 07 328Xi had this problem. I dumped the fluid and filled it. Ran it awhile to mix it all up. Drained it, dropped the pan and replaced the filter. Added to shudder fix to the bottom of the pan as its easier than trying to get it in the fill hole. Filled the fluid and its been fine for a couple of weeks now. Wicked messy job. Don't dig in any further than you have to.

[Leucosticte]

what fluid should I use? Last time I used BMW dexron 6.

[tlow98]

That or a lot of people have luck with the valvoline max life I believe it’s called? DOA. Search on here.

[nsjames]

any dexron 6 is fine, don't over pay for what's in a BMW bottle.

I used maxlife the last go around and haven't had any issues.

I can't say that I really noticed a difference, but it is cheap.

[mainbearing]

Valvoline Maxlife here. No problems (besides the always sh!tty shifting of the AFAIK 1st year E90 GM transmission).

@nsjames, how's the 08 shifting? A relative's 09 shifts so much better, but I wish BMW put in a ZF instead of going with a cheap junk.

+1 on more drains and refills plus the filter.

[E92William]

As much as everyone likes to shit on the GM transmission I think it should be taken in count how much cheaper it is to maintain. By 100k all zf transmissions are gonna be in need of new unicorn tear fluid by lifeguard, valve body seals, mechatronic seals, solenoids. The 6l45 only asks for torque converter additive and regular servicing. Bad shifting I'm sure will eventually be remedied by someone with a proper transmission tune for it on the level of xHP

[Leucosticte]

Originally Posted by mainbearing

Valvoline Maxlife here. No problems (besides the always sh!tty shifting of the AFAIK 1st year E90 GM transmission).

@nsjames, how's the 08 shifting? A relative's 09 shifts so much better, but I wish BMW put in a ZF instead of going with a cheap junk.

+1 on more drains and refills plus the filter.

I find it funny that people call it cheap, when the gm has a metal instead of the plastic zf pan. I've said it before and I'll say it again, gm and zf are the exact same stock.

[mainbearing]

We have a 6HP and 8HP in Audi's. Shift smooth as silk. Febi 39096 ATF from RM Euro (equivalent to ZF LG8, $70 for 5L) is what I use in both, priced right too at $14/L. I changed the fluid and filter at the recommended interval of around 50-60K miles and haven't experienced any solenoid problems. I did preventatively replaced the Double-D seal and mechatronic sleeve.

This GM 6L45 really shifts like sh#t in comparison. Shame on BMW putting one in here to cut cost. Again, my relative's 2009 shifts so much better, so I think GM's 07-08 had problems. No way they're anywhere near our ZFs.

Here is the picture of the Double-D seal from the 6HP19, still good after all these years, fortunately. Yes, I hate to see so much plastic in German designs (like that coolant bypass tube over the radiator, &%$^! ), and do prefer metal as you said, but luckily no problems with our ZFs, other people's experience clearly vary.

https://www.e90post.com/forums/showp...08&postcount=8

[Leucosticte]

then your transmission must be in trash shape, ive driven the zf in my friends 330 and the gm in my car back to back, they feel the exact same.

[E92William]

The transmission in my 328 is very smooth sometimes you can't feel it shifting. The 6l45 is related to the 6hp, quite similar design so there's no reason to think it is any worse than the zf box. Also worthy to keep in mind the same transmission with some internal modifications is used for heavy duty and V8 applications as the 6l80 and 90. I'll go as far as saying this transmission in the 6l90 form would probably be stronger than a zf. Though I guess we can't confirm in this chassis since it wasn't mated to the N54.