DCT transmission leaks, wrong fluid, and general questions

[deansbimmer]

I picked up a 2012 E93 M3 (32k miles) at insurance auction to rebuild for my wife (engine hydrolocked). One of the other issues was a transmission leak. There was so much oil throughout the undercarriage that I was not sure what seals were leaking, and which ones weren't, so I am doing all of them while the engine is out and I have easy access.

One of my concerns when draining the DCT is that the fluid that came out is red and still transparent, which tells me that for some reason the shop that had attempted to repair the car previously (a very generous term) had filled it with something other than the factory fluid which is amber in color.

Since the shop cheaped out on everything else, I assume that in the best case scenario they used a cheaper DCT fluid alternative like MOTUL, REDLINE, HKS, etc. Given the sh!t level of work done on the engine however, it is entirely possible that they filled it with whatever generic ATF they had on hand.

Does anyone have any experience with these alternative DCT fluids and their colors? Is any of them red? I am in the process of trying to evacuate all of the red fluid from the transmission and cooler lines. What possible issues could I face if the transmission had been used for a short period with an ATF fill? (I imagine less than 100 miles- the mileage their "rebuilt" engine lasted.) Is there a possibility of any significant permanent damage?

I am replacing the front bell housing O-ring, the mechatronics pan gasket, and the main pan. Also installing new suction and pressure filters with new Pentosin.

[nholmes]

Send a sample of the fluid to Blackstone for analysis is what I would do.

[rantarM3]

Look at this thread regarding filling the transmission with something other than the proper DCT fluid: http://www.m3post.com/forums/showthread.php?t=1078744

Long story short, Helmsman had his tranny replaced (along with the cooler and lines).

[BzsBimmer]

Your best bet would to do a complete year down of the trans and replace all hoses and seals.
I'd really be concerned with any fluid that gets stuck behind in passageways if you don't know exactly what fluid was previously used.

The clutch plates might have the old fluid absorbed in it as well as the solenoid actuated valves.

You may want to contact SSP for info. Only a couple of places that I can think of who really know how to service the DCT but not an impossibility.

[Richbot]

Unless somebody decided to use pink shoe polish, that's got to be ATF. Luckily there is no torque converter holding a gallon of that shit in there.

[nholmes]

I wonder if GETRAG has a procedure to flush out bad fluid.

[deansbimmer]

I really am curious if it is Redline DCT fluid, you can get that stuff just about anywhere and it's cheap. I can't find out what color it is online, so maybe I'll run and buy a bottle of it to find out.

I have evacuated about 7 measured quarts so far, not including the amount that spilled or got sopped up in towels. 3 quarts shy of the 10 quarts used to fill a dry system but maybe enough to get away with if I do another drain and fill in a few miles. I don't think the transmission was run enough to do anything other than distribute the fluid throughout the unit. It's true that the clutches would absorb the fluid, but since they would have already been saturated with the proper fluid, I'm thinking they may be OK after this flush. Worst case, I have a spare DCT I can install later on if this one fails.

After I pulled the sump pan it was immediately obvious why they added fluid. They had JB welded a cracked pan instead of spending the $150 for a new pan and gasket. Asshats. At least ATF was designed for AT clutches and has friction modifiers for that type of use.... The thread posted above was what happened when the dealer installed manual trans oil. I would think that would be far less hospitable to a clutch assembly.

I replaced all the filters and gaskets and sucked out as much fluid from the mechatronics and bellhousing area as I could get to. Removed and drained the cooler and lines, and installed new O-Rings there too. I'm going to button it back up and hope for the best.

[nholmes]

Originally Posted by deansbimmer

After I pulled the sump pan it was immediately obvious why they added fluid. They had JB welded a cracked pan instead of spending the $150 for a new pan and gasket. Asshats.

Holy shit.

[///Mobbin]

Cool thread, keep the pics coming and good luck with the rebuild!

[BzsBimmer]

some people....
At least it's in good hands now

[deansbimmer]

So I reckon I got out 8 quarts from the various areas and the filters. I'm going to go pick up some Redline fluid to check the color. If it's red I'm going to gamble and not worry as much about it.

To give you an idea of the "quality" of work of these clowns, this was some of what I found in the "rebuilt" engine. (they rebuilt it because it hydrolocked).

They "honed" two of the bores. This was how it looked when I opened it up. Mind you this was assembled and sold as "repaired" to the customer.

They didn't have the correct piston (bank 1 vs bank 2). Solution? Grind off one of the skirts on the pistons for clearance!

[///Mobbin]

I had no idea it could be that bad, wow.

[deansbimmer]

I looked up the MSDS for the Motul and Redline, both are amber in color so its probably safe to assume the idiots filled it with ATF.

It seems some of the characteristics of a couple types of Redline ATF are similar to the DCT fluid and their DCTF is compatible with factory and other DCT fluids, so it may not be an immediate reason to condemn my DCT. We'll see how it goes.

[RoundelObsession]

Originally Posted by deansbimmer

I looked up the MSDS for the Motul and Redline, both are amber in color so its probably safe to assume the idiots filled it with ATF.

It seems some of the characteristics of a couple types of Redline ATF are similar to the DCT fluid and their DCTF is compatible with factory and other DCT fluids, so it may not be an immediate reason to condemn my DCT. We'll see how it goes.

Hey Ed,

Redline ATF is red in the weights i have used, which is D4 ATF and D6 ATF.

[deansbimmer]

Originally Posted by RoundelObsession

Hey Ed,

Redline ATF is red in the weights i have used, which is D4 ATF and D6 ATF.

True. I wasn't clear in my post. Their DCTF is amber. Their ATF products are still red.

I've reached out to Kris at SSP to see if he has a take on this misfill. I hope I'm not wrong in thinking that filling a DCT with ATF isn't as bad as filling it with MTL.

[Richbot]

Holy shit. That's criminal

[WingZeroX5]

What kind of horseshit fluid went into the transmission? Fresh fluid should be light amber

[Shredicus]

WOOOOOOOW

That is terrifying

[Helmsman]

Ouch, seems you've run into some even bigger clowns then I did Dean. Assuming you got her for the right price, good luck with the repair man!

[deansbimmer]

Salvage auctions are a crapshoot. The sellers always do the bare minimum to get them to limp across the block for the highest bid. They're all clowns.

Kris responded and said that the ATF will eat the seals and clutches in the DCT. He suggested their flush kit, which looks very thorough at 24 liters of fluid. It looks like they flush 12 liters of mineral oil through, then flush 12 more of their DCT fluid. By suggesting a flush kit and not a "new transmission", I take that to mean their might still be hope.

I've asked for clarification but at this point I don't know if that means immediate destruction of the transmission or if it means I simply won't see it last to 100k, which is completely fine. Hopefully I'll get some miles out of it seeing as I just blew over 800 on flush and gasket stuff, LOL.

[dparm]

The DCT fluid is basically a GL-4 75w85 gear oil/manual trans oil with some special additives.

ATF is way thinner, pretty much regardless of what specific variety it is (D4, D6, etc). In some cases, it might be 25% thinner or more. The add packs on that will also be very different and I have no clue what they'll do to the internals of the DCT.

[///Mobbin]

Curious what your plan is for the block and pistons?

BTW, this thread makes me want to buy an engine just to take it apart, keep it up!