BMW E90 335i 6AT 6HP21 FULL SERVICE - GEAR SHIFT FIX 

Thanks man, yeah i went through days of research and i have done a few now. I tried to keep it simple and show what i think is the best place to start for most guys.

Man it makes it feel so much better. Totally worth the atf shower you get through the process.

Yes yes yes 🙌

Glad it was helpful!

What do you mean with slippy feeling?

Good to know!

Glad it was helpful!

How does a pan effect shift quality?

WOW. thats impressive. I'd bet money a refresh would give it a new lease on life

@@ZeroTo60Tube hey , just want to get your opinion, my n45 is pushing around 450whp on hybrid turbo, the 6hp trans is slipping on 5th and even 6th gear, do you think a friction plate rebuild is needed? or we just a solenoid and sleeve service will do ?

@@carsonwong Possibly, however my understanding is lack of oil pressure is what causes the frictions to wear on most cars. It really luck of the draw with older trans.

It’s really hard to recommend someone. The only guy I know we’ll enough in the entire bris area is Dan from simply tuning. But he is a specialist for going fast and you will be paying a lot of money for maintenance that could be done at a cheaper rate. I know of a lot of shops in bris that say they specialise in euros. I don’t know of any that are actually good at it when the cars get a bit of age on them. The specialists are great for servicing and modding new ish cars but don’t have the experience with older stuff, so you pay through your teeth. Can recommend a mate up here on the coast. Shoot me an email if you want his contact details.

@@ZeroTo60Tube you are absolutely right Andrew I’m not entirely sure any euro specialist in Brisbane are N54 specialist. One mechanic in Newmarket who I got the car analysed from asked me to sell the car due to a few oil leaks. I asked him to send me a quote for the repairs and he still has not. Which has me worried! Nevertheless, I’ve sent an email through to your gmail account. Looking forward to your reply. Thanks heaps!

Honestly its purely because i have never personally seen a trans that needs a zip kit. Thats all. Im sure they exist for a reason, just not seen it needed personally.

@@ZeroTo60Tube Depends on the mileage really. Most businesses that repair these transmissions appreciate the wear that occurs in the valve body over time, especially if the trans has not been oil/filter serviced appropriately. Many parts in the zip kit are designed to address those issues. Downside is that you will need to buy a new seperator plate as these ruin the gallery seals once removed, but they are cheap enough. BTW, a year later I paid $74 for 4 litres of Penrite fluid. And the ZF manual says the adaptions must be cleared and a relearn done if you change the soleniods. This is specific.

Hello, are adaptation and relearn mandatory if i want to change solenoids on my 6hp26 ? Thanks

Sorry for the late reply, had a lot on lately. They are on FCP euro, probs best place to get them in the states.

I've put some updated info in the Zeroto60 G chat about the adaptations. Man it makes a big difference.

I would, xhp destroyed my tranny aswell as quite a few of my friends that have it. 3rd and 4th gear get destroyed

I may end up with a sutfin tune. But like I said at the start of this series. I know what actually works and will be showcasing that first.

Can we get more content on the m5

@@derricknash4548 yes yes, more content on all the cars to come.

Absolutely not the atf is amazing. Used it in my old 6at, which is still the only 6at I am aware of that snaps axles. However can you link to a video of yours going through the gears in different modes pls. Keen to see what it’s like. Also what dme flash do you have?

@@ZeroTo60Tube Heyyo, I'll take a video and message you with it. Currently running MHD Stage 1 as well.

@@TIPh0enix Cheers man! Just post a new comment wiht a video link, it will be the quickest way to get it in my eyes. The messages can sometime build up a little..... :S or a lot.

@@ZeroTo60Tube Haha understood. Please ignore the parkinsons spec recording, not a seasoned YT veteran lmaoo Here you go man: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-5b1P2R4oWaU.html

How did retrofit work out.

@@BimmerMafia It was well worth it. Car shifted great with the low mileage valvebody and v3 tune. I would definitely do it again.

Did you solve it ? I got the same problems on the same car/engine. I was thinking about changing the solenoids, sleeves, oil etc, but I m afraid of spending money for nothing and other thing being the problem.. Waiting for your answer ✌️

Look don't tell anyone, but back in the day when i did my ZF6 in the x5 in 2018 and my zf6 in the 17t car in 2019. I did the legit proper learning process, every god damn step to a tee, it takes ages and you really have to do it at night and a decent road. Now I just do 5-10 light accelerations in d, or until its shifting right at say 25% throttle. Then the same at 50%, then the same at 75%. I come to a stop after every acceleration. If i find it flaring on a particular shift i will keep doing it until it's smooth. Then i do sports mode at 50%, 75% and 100% throttle and then just do manual mode at 75% and 100% thottle for the manual mode, i dont bother coming to a stop just do a decent pull thought 1st to 4th. After that i come to a complete stop and go reverse for 2-3 seconds back to N about 5 times, then the same for D. I will also do some short shift in manual mode at wot. Basically put the trans through the conditions i drive it. However you have to do that light load learning in d mode first.

@@ZeroTo60Tube Cheers for confiding that little pearl! I've taken note, and with the forecast for brilliant weather this holiday weekend, will go out and follow your method precisely. Man what a relief - that's been bugging me. Thank you so much!

Its for the love of the platform. I want people to be able to do this stuff themselves and not waste money on things they dont need.

From experience, yes. But only if you are chasing acceleration numbers or racing. They control shift times which is a big deal for these things.

Do you have video where you flash xhp after this repairment? Do you feel the change and power of xhp flash then?

Thats unfortunately it had worn the bushings. Obviously it will happen if the trans is abused enough.

Fcp euro from memory.

It doesn’t. But we have some ready to go.

I should add to that. I want to see how it behaves on the ones in. See if they are a problem or you can away with older injectors when you have port injection.

Not sure about protool, but I believe it can. Definitely worth doing in my eyes.

i just 8hp75 swapped mine. pure drivetrain solutions stage 2 8hp75 good for 1600ft lbs 5k rpm a90 supra torque converter with billet stator. 8hp75 with 3.31 final drive is identical to the a90 supra 8hp50 gearing with its oem 3.15 final drive. the a90 is deep in the 8s and my 335i weight about 2540 lbs and makes close to 1000 wheel im hoping when i get the driveline and axles in sometime in the next few weeks its going to finally come together. ive been through a few built 6hp trans , kept breaking input shafts. car is going 8s at tx2k for sure. i almost went with the same swap you have im curious to see what our cars would do side by side.

Hey man, been following your build. Keen to see some 5 second 60-130 times..... :P No excuses with 30psi and your trans now hehe!

@@ZeroTo60Tube The season is over for me now here in cold and snowing Michigan and I have a built motor with the largest twins ever made for our platform going on it. They are 1 out of 20 Twin 53/53 dual ceramic ball bearing MMPs 1000whp capable twins. I broke into the 6s on my second revision and 60-130 attempt on my stock motor and franken turbos but I am aiming to hit into the 4s with my new setup this winter.

​@@N54GASM Any updates on the setup?

It will be a coding issue.

Wise words..... sorry i missed this only 12 months late

Absolutely a possibility, but not something I see a lot of. Or generally if the internals are shagged the box will be throwing errors.

It’s a BMRetrofit usb.

I will get ista on it today and re-check

So just checked it again, took the car for another drive this morning. Reset adaptations in MHD for vanos, octane and a few other things. Car is driving better again. Clutch fill pressures are A:5.0, B:18.0, C:7.0, D:18.0, E:0.0 all rapid fill times are currently 0.0. So huge change from prior to doing the maintenance. Super happy with how its driving this morning.

Could be an oil pressure problem based on what you are describing. What ever it is, it will be an internal issue in the box. Please update this comment when you find out what it is.

@@ZeroTo60Tube Figured it out. I was checking the line pressure before the cooler like an idiot and not after (at the cooler outlet). Turned out the cooler was clogged with clutch material likely from before I had the new packs put in which prevented the pressure needed to engage the gears. Been meaning to upgrade anyways so I switched to a stand alone BMS air cooled unit that sits in driver side wheel well just like the engine oil cooler does on the other side...more work than I felt like doing but now it's flawless. Doesn't explain why I could rev it to 3000 in neutral and make the car crawl...but It's not doing that anymore and shifts better than brand new with xHP Stage 4 flashed.

Dustin I am so sorry I missed this comment. It will likely be the shift selector sensor in the box. Just needs to be lined up with the fork as the mechatronics goes back in

@@ZeroTo60Tube we lined it up with the part that slides. Is it supposed to be all the way towards the front ?

Also thanks for the response

@@wickedclwn05 It had a fork like part that lines up with the end of the rod. See the top middle of this photo. The fork is on the other side of the rod. s32667.pcdn.co/wp-content/uploads/2020/01/TD200709_ShiftPointers_02.jpg

@@ZeroTo60Tube so the plunger should be slide to towards the solenoids?

Its worth trying this. However the more i learn, once they start to slip the damage is done.

I've seen that with dirty oil. I would recomend change, oil pan, seals etc

There is no set way for every car. Different tyres, different power levels and different road surfaces will all require a different technique. However get yourself a draggy and get experimenting. You can set the dragy up to measure your 60ft times on every launch and the data you get from that will be invaluable.

@@ZeroTo60Tube thanks for the reply!

You can. But I would look at selling the car and swapping to a n54. Will be cheaper in the long run and twice as fast.

Have you done everything i showed in this vid?

@@ZeroTo60TubeI replace the fluid and filter about a month ago but no, didn’t replace the solenoids. When I’m just driving normally it shifts perfect, it’s just while in 3rd-4th gear at high boost

@@Sooners84Gaming Well get on to the solenoids and seals. Sounds like this video is just what you needed.

No, oil temp around that 110-125 normal on these things. Keep in mind its oil temp.

A good condition trans will hold 800hp at the crank. Maybe more, if you have decent software on it. This one has been miss treated by previous owners. Like never serviced before 190,000ks, i still intend on pushing that 800hp figure through it. My other car was over 700hp and again poorly maintained trans, that never skipped a beat at over 700hp. But like in the video i did all this stuff to my other one too.

@@ZeroTo60Tube Thanks for the information. Love the videos

You have the 6+6 or 11 blades?

Dude that’s a shame. Going to unbox the new turbskis today. DAW

@@Nick-wu5cl 6 blades, thats the upgraded version which these guys showed in video.

@@ZeroTo60Tube ohh hell yeah! As per your video, one of your mate is running the viv v3s, how is it going? I will be pushing no mote than 21 psi boost. I got tune file from WedgePerformance

@@TCGTV98 the guys with the v3's is having fun, but there is something not right with the car, when we actually work it out we will share. Have a few ideas.

Ive tried to follow a few forum guides and its never worked for me. But there a few DIY guides on forums to get it setup.

@@ZeroTo60Tube Thanks I've decided I'm going to avoid the hassle and just buy ProTool and do it through there. Another quick question though, for the refill procedure could you just confirm that you 1. Fill it to overflow with engine off, 2. Start engine and fill to overflow, and then with engine still on 3. Go through gears and wait till trans fluid is at least 40 C before doing third and final fill to overflow? Thanks again.

@@jackvanhaverbeke1363 That is exactly how i fill them. It may also be worth checking it again after a drive.

@@ZeroTo60Tube I’ve been running xhp for almost 3 years now, I’m thinking of flashing back to stock before the install, then reflashing a tank or two of gas after I do the re learn procedures. Would you recommend that or just leaving it ?

Clutch Pack E is gone on your transmission. You'll need a rebuild or swap in a used trans. Happened to me and I completely lost the ability to shift into gears 4-6. Keep an eye on your transmission temps. I was quoted 4500$ for a transmission rebuild. Used trans swap will run like 1300$ for labor and trans oil and rear main seal. Shop sourced me a trans for $1400 so I could get a warranty out of it. I'm stage 2+ 93oct. I'd say being tuned really made the issue worse. Stock power levels the trans was fine

FYI I also replaced the solenoids and gaskets and did new filter and oil before clutch E blew. It felt better but it only delayed the inevitable.

Thats sounds like a potencial issue with converter. If it stalls the engine when you put it in drive the converter is not opening up like it shoud.

@@ZeroTo60Tube I really appreciate it because I reached out to the person who rebuild it he told that I need a new VALVE BODY & TCM just wanted to make sure before buying stuff that I don’t need

Doesnt matter, you just have to line the shift rod up when you put it back together.

@@ZeroTo60Tube Thank you.

Lol, i can't missed this comment! Did have laugh 12 months on

Did you fix the issue? My car won’t come out of parking

Im yet to see a car thats needed a zip kit. However im sure if your trans is particularly bad they are wroth doing.

@@ZeroTo60Tube pushing 650hp on my n55 running at 27psi with only the zip kit done to it zero slips. Never upgraded the solenoids. When I took the valve body apart found the little Circular puck pieces dead flat not holding any pressure. It’s been 15k miles and the car has 177k miles 🤞🏽

Being a f series you should have the zf8. Which is a much better box. The zf8 uses a seperate oil pump system which doesn’t have the pressure losses like the zf6……… yet. However even though the zF8 seems pretty good or at least we don’t know common failure points yet. It’s still worth doing a fluid change if you have modified the motor.

I believe in my case a fluid change is what I have to tackle

This made it better. However i didnt realise how much power the motor was making at the time. I actually blew the motor and the trans up about month after this. But she making over 700whp when it did the trans.

Mainly because i haven't seen the need for one personally. I know there are a lot of people that have issues at these power levels with the 6AT, but my 17T car never even started to play up at over 700hp and that was without even running the line pressure bump, so i am looking to see how this ones goes at around the 800hp mark. The HP28 is great if you are snapping shafts or if you have clutch slip issues. But realistically you shouldn't be having those issues if your 6at is in good nick.

If you supply the parts it should be 3-4 hours labour, plus the relearn process.

Alpina and xHP flashed transmissions display the actual gear you are in. its brilliant.

@@ZeroTo60Tube which would you recommend?

@@ThisLaoGuy xHP all day long. Alpina tune is free if you have a laptop with winKFP setup. But the xHP flash is much much better. This car will be getting xHP before the power gets wound up.

@@ZeroTo60Tube thank you.

Haha

We keep learning.

@@ZeroTo60Tube seals just arrived. Still waiting on the Solenoids, but I'll fit the seals to hopefully make the car driveable and then do solenoids at a planned time.

And what it is that causes the clutches to slip?

Materials engineering and composite materials are extremely robust with huge weight and manufacturing benefits. It’s not a downgrade!

You have to hand it to BMW it’s a cost vs chance of failure calculation that they nailed, these things last really well, well past the new car warranty period. I feel you need to give them a decent birthday every 10 or so years when they are in daily use and at least all the bits are cheap to replace. Not like a metal part that might last 50% longer and cost 3-4 times the price

@@ZeroTo60Tube your right I love my e90 n52. I believe I’m the 3rd owner and if that’s true I lucked out cause the first two owners took fantastic care of her. Until the person I got the car from had it sitting or they sold it to me as the bigger issuers were starting to show there ugly leaky seals… but all in all I can say that for them using so much plastic I can say that a lot less has gone wrong with my car then I was expecting. But again it goes back to treating the car with as much care as you’d want it to give you. 🤣. And to some that’s a funny thing to say but I can say from experience that every car I’ve ever owned and not just bmw. If you take care of them they will take care of you.