DCT Clutch Slipping

[RugbyBro]

Ran into some unnerving clutch slippage at the track today. So in order of what happened today:

1. Under WOT there were moments where the clutch would slip in gear, revs would shoot up, I would then reduce throttle slightly and the clutch would re-engage as if nothing happened. This would happen mainly on sustained WOT, so not when I rolled into WOT coming out of corners.

2. At one point later in the day the car was quite hot, on a fast lap the car just popped into neutral instead of up shifting to 5th. It would not go back into gear while rolling, so coasted the car back to the pits in neutral. Once in the pits, the car was shut off and restarted - the engine was misfiring and sounded rough. It was then turned off and started again and everything was back to normal. Car was also low on gas so fuel cut may have been a factor in this instance.

The only major thing that I did prior to this track day was tapping in my AIM solo 2 dl into then CANBUS.

Anyone else encountered this issue on any F8X? Im thinking at the least it’s a transmission flush and adaptation reset or potentially replacing the clutches. The car is only at 28k miles and always been at stock power. It is heavily tracked though (10+ days a year).

[jfritz27]

Originally Posted by RugbyBro

Ran into some unnerving clutch slippage at the track today. So in order of what happened today:

1. Under WOT there were moments where the clutch would slip in gear, revs would shoot up, I would then reduce throttle slightly and the clutch would re-engage as if nothing happened. This would happen mainly on sustained WOT, so not when I rolled into WOT coming out of corners.

2. At one point later in the day the car was quite hot, on a fast lap the car just popped into neutral instead of up shifting to 5th. It would not go back into gear while rolling, so coasted the car back to the pits in neutral. Once in the pits, the car was shut off and restarted - the engine was misfiring and sounded rough. It was then turned off and started again and everything was back to normal. Car was also low on gas so fuel cut may have been a factor in this instance.

The only major thing that I did prior to this track day was tapping in my AIM solo 2 dl into then CANBUS.

Anyone else encountered this issue on any F8X? Im thinking at the least it’s a transmission flush and adaptation reset or potentially replacing the clutches. The car is only at 28k miles and always been at stock power. It is heavily tracked though (10+ days a year).

Hasn't ever occurred for me.... yeah, would probably do the easy things first in terms of mitigating trans temps as you said (DCT service with the BW overfill kit, maybe Motul high-torque fluid vs Redline or similar). I also opted for the metal pan that BW sells, might buy you a few degrees (note that with that pan, don't try using a replacement magnetic plug in the stock size -- it's a smaller size, I just kept the plug that came with it)

If it happens despite that, then I guess time to start replacing stuff...

[Wanted_M]

I say flush, new filter and add a larger DCT pan either from Seems Legit Garage, Burger, Vargas or IND/Fall Line are all good options. This will help you manage temps, sounds like you've degraded the DCT oil and should have been replaced due to your high track usage. Try that first then add a DCT cooler from CSF or Mishimoto, as they are two pass design.

The price we have to pay, good luck man. Keeps us posted on your findings.

[RugbyBro]

Plan of attack right now is:

1. Transmission fluid flush
2. Bimmerworld dry-break / overfill kit
3. Trans tuning to increase clamp force - either OE GTS or XHP

Wanted_M do you know much about the XHP trans software - I saw you posting in the XHP thread. Mainly wondering if the extra tunability is worth it over the GTS flash.

[jfritz27]

Originally Posted by RugbyBro

Plan of attack right now is:

1. Transmission fluid flush
2. Bimmerworld dry-break / overfill kit
3. Trans tuning to increase clamp force - either OE GTS or XHP

Wanted_M do you know much about the XHP trans software - I saw you posting in the XHP thread. Mainly wondering if the extra tunability is worth it over the GTS flash.

For reference, when I recently did my pre-emptive DCT service, I precisely measured what came out (letting it drain overnight from warm/hot), and it was 6.5 quarts. With the overfill, you add 1 extra. Accounting for about 0.5 quart of spilling/etc, I used just about all of the contents of 8 quart bottles of fluid.

Helpful tidbit: screw the blue banjo fitting and black extender/coupler piece together first before fitting it to the trans

[RugbyBro]

Originally Posted by jfritz27

For reference, when I recently did my pre-emptive DCT service, I precisely measured what came out (letting it drain overnight from warm/hot), and it was 6.5 quarts. With the overfill, you add 1 extra. Accounting for about 0.5 quart of spilling/etc, I used just about all of the contents of 8 quart bottles of fluid.

Helpful tidbit: screw the blue banjo fitting and black extender/coupler piece together first before fitting it to the trans

Awesome - appreciate the insight! Part of me also has a buy-once-cry-once mentality about this and am strongly considering just doing the clutch packs preemptively.

[jfritz27]

Originally Posted by RugbyBro

Awesome - appreciate the insight! Part of me also has a buy-once-cry-once mentality about this and am strongly considering just doing the clutch packs preemptively.

Yeah, my suspension self definitely hears you bigtime on that one (), but for this if it were me I'd definitely wait to see if the easy stuff works first. Your mileage is so low (like mine).

[Wanted_M]

Originally Posted by RugbyBro

Plan of attack right now is:

1. Transmission fluid flush
2. Bimmerworld dry-break / overfill kit
3. Trans tuning to increase clamp force - either OE GTS or XHP

Wanted_M do you know much about the XHP trans software - I saw you posting in the XHP thread. Mainly wondering if the extra tunability is worth it over the GTS flash.

Yes, I have XHP stg2 on CS and so far, all good. No issues with clutches or clunkiness. The DCT Hardware # is higher on the XHP flash for EU so that's what you'll get. I contacted the dealer and asked if there was a DCT update for my VIN and they said no, I had the latest. My original ended in .064 and upgraded to .066 and you can't revert back to .064 unless kubax reloads your original. You'll have to play with the settings to suit your needs, we can compare notes .

[prisco]

My chutches did not hold to pure stg2+ @30psi. XHP fixed!

[SYT_Shadow]

At the track, eventually you can run into DCT issues, and depending on what you mean by "heavily tracked", it will require more work in the future. Fortunately it's a rare occurrence and most people will never experience it due to pace.

The engine running rough throws me off a bit, no DCT error should cause the engine to run rough. I'm surprised it even audibly slips, the ECU should cut power when it senses any slip at all.

Stage 1: Cheap solutions:
Put new fluid in. If you are using OEM and switch to Redline, it needs a full flush (or two normal changes) to get the old fluid out.
BW has a thermostat bypass
BW has an overfill kit

Stage 2: Less cheap solutions:
The Slon DCT pan. Unlike the other ones discussed, it has more baffling and adds a spacer to lower the suction point. To have a bigger pan but to suck from the top will still allow the DCT to oil-starve.
XHP software, which clamps more than the GTS software
Bigger DCT cooler

There's more, but every time it gets more expensive!

[jfritz27]

Originally Posted by SYT_Shadow

At the track, eventually you can run into DCT issues, and depending on what you mean by "heavily tracked", it will require more work in the future. Fortunately it's a rare occurrence and most people will never experience it due to pace.

The engine running rough throws me off a bit, no DCT error should cause the engine to run rough. I'm surprised it even audibly slips, the ECU should cut power when it senses any slip at all.

Stage 1: Cheap solutions:
Put new fluid in. If you are using OEM and switch to Redline, it needs a full flush (or two normal changes) to get the old fluid out.
BW has a thermostat bypass
BW has an overfill kit

Stage 2: Less cheap solutions:
The Slon DCT pan. Unlike the other ones discussed, it has more baffling and adds a spacer to lower the suction point. To have a bigger pan but to suck from the top will still allow the DCT to oil-starve.
XHP software, which clamps more than the GTS software
Bigger DCT cooler

There's more, but every time it gets more expensive!

And with the Slon (or similar sized) pan, I think you have to make a cut-out in the undertray cover as it protrudes lower, no?

[SYT_Shadow]

Originally Posted by jfritz27

And with the Slon (or similar sized) pan, I think you have to make a cut-out in the undertray cover as it protrudes lower, no?

No, it just fits inside. Keep in mind the M4 GT4 runs without the cover, so now that's how we run the GTS1

[sly1types]

What tune/Power level are you at? Did you get any DCT temp warnings, I think its about 250F.

I was getting over temp warnings my last event of last year. I pulled the DCT cooler out and replaced it with a CSF one. The old one was pretty beat up, but more importantly there was a lot of highway trash and leaves behind the dct cooler prohibiting flow. I already had the overfill kit, its pretty neat.

How old was your fluid?