Warning and questions re DCT leak.

[jeff4598]

I was very lucky to be having my rear toe link upgraded to Dinan so the great guys at Motor Works West found a DCT leak when the shields were removed for the install. This with only four weeks of warranty coverage remaining!

BMW is changing the side and bottom gaskets because they cannot be sure wich one has the leak. There is little chance of finding a leak unless shields are removed. Maybe it's worth doing now and then to avoid a damaged transmission.

BMW is avoiding my inqueiries re how much fluid was lost and as to whether a low fluid level could cause premature transmission failure. Does anyone have suggestions as to how I can protect myself as my warranty is expiring and this issue came up during the warranty period? Thanks!

[j2m]

Thanks for posting.
A couple weeks ago I found the same problem on my 2011 with 7,500 miles. There was residue of drippings on the tray and fluid on the gasket side. A few of the screws were loose, so I tightened them up. Still need to get my car into the dealer to get checked.

[besiktas]

Is this something i can check myself or does it have to be at a shop to look under the shield?

[BPMSport]

This happened also to one of my customers that tracks his car about 20 times a year. BMW fixed it under warranty without issue.

[jeff4598]

I assume fluid would eventually spill out past shield but don't know for sure. My car has 27K miles and never on a track or used launch control.

[jeff4598]

Car is back. SA confirms that I would have known there was a leak "when you started to hear weird transmissiony grinding noises"- very reassuring!

They replaced transmission gasket and pan gasket and changed fluid. Nice to get a free change of fluid- supposed to never need to be changed but cannot hurt to start with new fluid at 27,000 miles!

Wish me luck out of warranty!

[kenwelch]

Originally Posted by jeff4598

Car is back. SA confirms that I would have known there was a leak "when you started to hear weird transmissiony grinding noises"- very reassuring!

Like automatic transmissions the BMW M-DCT is pressure lubricated and the double clutch requires fluid pressure to apply (engage). If the fluid level dropped low enough for the hydraulic pump fluid pick-up to begin sucking air there would not be the hyd. pressure to engage the clutch to move the vehicle.

Usually what happens first with automatic transmissions is they slip into "neutral" when cornering because of fluid movement away from the pump pick-up. The driver might notice the engine rpm's rise in the corner and once the vehicle is traveling straight again the transmission slams back into drive.

The M-DCT would likely have similar symptoms. Hydraulic pressure is also required to make gear changes in the M-DCT. Fluid pressure is used to move the shift rails/forks to operate the synchronizer assemblies.

At a total system volume of about 9.5 liters of fluid (8 liters in the trans), you would have fluid spilling off the transmission under-cover to get the fluid low enough to begin displaying the above problems.

[freeman727]

Would this be covered with the extended Powertrain warranty? I'm wondering whether to get platinum or powertrain only extended warranty.

[jeff4598]

All warranties are by definition bad gambles because the seller has to make a profit overall. Like any other insurance it is only worthwhile if an expense without the insurance would be financially devastating to you-like your house burning down or you car being stolen. So insure only what you couldn't possibly pay for without insurance.

I have a LOT of Dinan mods and Dinan just came out with a full coverage plan but it's $5400 for 2 additional years. It's good up to 100,000 miles but I will only have ~42,000 when it expires so I'm gonna take my chances. I have $5400 imaginary dollars in my "repair fund". I let you guys know where I stand along the way to the 2 year mark when my $5400 policy would have expired.

[OC3]

Some of us who track our M3's have had DCT fluid changed. Probably easy to fill it up, if some leaked.

[///M Rakete]

Originally Posted by jeff4598

All warranties are by definition bad gambles because the seller has to make a profit overall.

Right, the seller prices the warranties based on the anticipated claims, over the subscribed base, so as to make a profit be be competitive. However, there will be some people who claim and get more than their premium. For them it isn't a bad gamble at all.

[White 13]

Originally Posted by OC3

Some of us who track our M3's have had DCT fluid changed. Probably easy to fill it up, if some leaked.

Was the change covered by warranty?
What determined the need for a change?

Thanks.

[positiveions]

Wow, thanks for the info.

[jeff4598]

Originally Posted by ///M Rakete

Right, the seller prices the warranties based on the anticipated claims, over the subscribed base, so as to make a profit be be competitive. However, there will be some people who claim and get more than their premium. For them it isn't a bad gamble at all.

You cannot evaluate a gamble retrospectively. It's not called a gamble at that point it's called "history". Can I have some of that $90 Google stock please?

[jeff4598]

Re Change: they had to remove bottom gasket to replace it- fluid comes out- new fluid gets put in. Covered.

[fayebym]

There was residue of drippings on the tray and fluid on the gasket side.

[jeff4598]

nothing on either gasket so they replaced both.

[Throtex]

I had sporadic temperature warning messages come up over the past few months. Whenever it would happen, the transmission would shift erratically, and the crawl feature would be disabled. I was living with this for a while, until one day I got the overtemp message and the DCT went to neutral (just as I was pulling into a parking spot!) Waited a couple of minutes and was able to limp in.

Later that day, I was able to drive it without problems to the dealership. They took a look at it and noticed a leak. They replaced the two gaskets, changed the fluid, updated the DCT software to the most recent built, and sent me off (with a $2700 bill ... I was two fucking months out of warranty! oh well).

A few days later, I got the basic warning message (transmission temperature rising, rather than the overtemp shut-off). Took it to service again, and they said they didn't see any leakage at all this time. I took the car back, but still got a couple of messages. They said it's normal and that the computer might take some time to reconfigure itself and stop reporting errors.

Did those of you who went through this repair continue to receive a few messages for a few days afterward? When they did the repair, they indicated that the transmission itself appeared to be fine. Not sure what could be causing the overheating. There's nothing blocking the transmission cooler that I can see.

[jeff4598]

The leak from the gasket is SLOW meaning it started BEFORE end of warranty- I would ask BMW NA to cover it. Sorry no knowledge re warning lights but if any transmission damage it should be covered under premise stated above.

[arielucrz]

I'm wondering whether to get platinum or powertrain only extended warranty.

[a.wang]

Mine actually just went in for a leak check, hopefully will hear back by tomorrow with an update. No track days.

[///M Power-Belgium]

Originally Posted by Lute

Seems we are seeing more of these DCT leaks and issues now. Must be quite concerning to DCT owners

No big deal,i changed mine preventive , but the DCT fluid (Pentosin) is ... $$$ !