Consensus when to do DCT Service?

[Gangplank]

So my 2011 135i w/ DCT has 90k miles on it now. We can all agree that the "lifetime" DCT fluid really means life of warranty give or take.

I'm thinking about doing a drain and fill on the DCT trans.

What is the consensus on when to do it? And do I just do the drain and fill or suction out and fill knowing not all the fluid will be new? Not interested in dropping the pan or trans if I don't have to.

I keep up on maintenance and am planning to have the car for a while.

Open to opinions, options, discuss…

[ashAZ]

I know I’m planning on doing it very soon. I have a 2011 135 DCT with around 133k on it. No trans issues at all, smooth, fast, tight shifts. I’m doing it for peace of mind. I don’t know if or when mines ever been changed.

The DCT isn’t like a normal automatic with a torque converter, so a simple drain should get the large majority of old fluid out. Most people will want to do a full service though, which includes a new plastic pan and new filters. There are a few good videos of guys doing a full DCT service and it’s not a crazy hard job. If you’re putting new fluid in, you should also replace filters. The pan is also plastic so tends to warp or crack at higher mileage.

You can simply drain through the drain hole and refill through the top of the transmission if you want to go that route and not change filters or pan, that should replace like 90% of the fluid at least.

I think if you DIY, you can get it fully serviced for $5-600 for all parts.

[zx10guy]

To do it properly, you should drop the pan and get all the fluid out. That said, I had a partial service done around 80k miles. Had the fluid drained and replaced the side filter in the trans. Getting to the side filter still required the trans to be dropped a bit for clearance. The other filter is only accessible by dropping the pan. My mechanic mentioned he didn't see any leaks from my trans and I didn't note anything either when I was under the car doing an oil change. So that's why I opted not to drop the pan and tempt fate.

I don't remember how much fluid my mechanic needed to fill the trans back up. I think it was about 4 quarts or so. But also keep in mind, you'll need to have the car perfectly level and have a scan tool monitoring the trans temperature. The only way to get the trans fluid to the proper level is when the trans temp reaches a certain range. For these two reasons, I opted to pay someone to do it.

Even though the DCT doesn't have a torque converter, I can't help but think there is some significant amount of fluid in the clutch pack area since the trans uses a wet clutch setup.

[Gangplank]

Originally Posted by zx10guy

To do it properly, you should drop the pan and get all the fluid out. That said, I had a partial service done around 80k miles. Had the fluid drained and replaced the side filter in the trans. Getting to the side filter still required the trans to be dropped a bit for clearance. The other filter is only accessible by dropping the pan. My mechanic mentioned he didn't see any leaks from my trans and I didn't note anything either when I was under the car doing an oil change. So that's why I opted not to drop the pan and tempt fate.

I don't remember how much fluid my mechanic needed to fill the trans back up. I think it was about 4 quarts or so. But also keep in mind, you'll need to have the car perfectly level and have a scan tool monitoring the trans temperature. The only way to get the trans fluid to the proper level is when the trans temp reaches a certain range. For these two reasons, I opted to pay someone to do it.

Even though the DCT doesn't have a torque converter, I can't help but think there is some significant amount of fluid in the clutch pack area since the trans uses a wet clutch setup.

Sounds like what I'm going to do. I'm waiting on a quote from my local Indy shop on a DCT service. Depending on cost I might just ask them for a quote on a drain and fill.

[StevieJ2]

Originally Posted by ashAZ

I know I’m planning on doing it very soon. I have a 2011 135 DCT with around 133k on it. No trans issues at all, smooth, fast, tight shifts. I’m doing it for peace of mind. I don’t know if or when mines ever been changed.

The DCT isn’t like a normal automatic with a torque converter, so a simple drain should get the large majority of old fluid out. Most people will want to do a full service though, which includes a new plastic pan and new filters. There are a few good videos of guys doing a full DCT service and it’s not a crazy hard job. If you’re putting new fluid in, you should also replace filters. The pan is also plastic so tends to warp or crack at higher mileage.

You can simply drain through the drain hole and refill through the top of the transmission if you want to go that route and not change filters or pan, that should replace like 90% of the fluid at least.

I think if you DIY, you can get it fully serviced for $5-600 for all parts.

There's a company that just started making cheaper cast pans for the autos, they said they're trying to get the DCT pans designed now. Almost the same price as the plastic pans. I'd personally wait before doing anything until the metal pans are available.

[Gangplank]

I had it done today. $450 for parts and labor. 4 liters of Motul DCT fluid and a drain plug + service.

[Gangplank]

After driving around for a few days I am surprised at how much smoother my car is shifting, and the reduced lag from a stop. I'd recommend it for anyone with a higher mileage DCT. I'd probably recommend it at around 75k to be honest.

[TWO STEP TEX]

I just bought a 2011 with 84k and I'll be changing mine in the next couple of weeks. I'll report back on difficulty and results. As far as I know, you can't really get all of the old fluid out without a flush and apparently it's not possible to fill it 100% without the specific software tool. I ordered the ECS kit with 5 liters of pentosin, 2 filters and drain plug. I'm going to most likely order a new pan and gasket. Looks annoying to perform, but the local shop wanted to charge me 535.00 to perform the service 😳

[Gangplank]

Update:

After a couple of months I started to feel what I thought was some clunky shifts or surging. And I was also getting an Intermittent smell of something burning. Not wanting to ruin my clutch I called the same shop that did the work and told them what was going on. After some discussion I asked them to order the parts and do the full DCT service. It took a week to get the parts from BMW. Actual kit and fluid from the dealer.

Turns out the burning smell seems to be from a leaking valve cover(?). So I guess I need to get that done. Anyone know what the valve cover should cost?

[blackcarbon92]

Originally Posted by Gangplank

Update:

After a couple of months I started to feel what I thought was some clunky shifts or surging. And I was also getting an Intermittent smell of something burning. Not wanting to ruin my clutch I called the same shop that did the work and told them what was going on. After some discussion I asked them to order the parts and do the full DCT service. It took a week to get the parts from BMW. Actual kit and fluid from the dealer.

Turns out the burning smell seems to be from a leaking valve cover(?). So I guess I need to get that done. Anyone know what the valve cover should cost?

I believe the gasket itself is only 30-$50 but labour could be between 3-6 hours, the higher side being if you DIY it so i'd say it's safe to say around $500 if your bringing it somewhere. I think i've heard somewhere close to $1000 for full replacement of vc and vcg at the dealer but a good indy shop should be a few hundred cheaper. Good luck!

[TWO STEP TEX]

Originally Posted by Gangplank

Update:

After a couple of months I started to feel what I thought was some clunky shifts or surging. And I was also getting an Intermittent smell of something burning. Not wanting to ruin my clutch I called the same shop that did the work and told them what was going on. After some discussion I asked them to order the parts and do the full DCT service. It took a week to get the parts from BMW. Actual kit and fluid from the dealer.

Turns out the burning smell seems to be from a leaking valve cover(?). So I guess I need to get that done. Anyone know what the valve cover should cost?

I.bought one for around 200.00 but it's not oem. Comes with the gasket. I'm only changing the cover because my pcv system is chirping, it may not be necessary for you unless yours is warped or something. It's really not that tough if you have tools and a little patience. I plan on doing mine in the parking lot this week.

[Gangplank]

Well since I've got burning & some smoking going on I think I'm going to do the full replacement. My car has 90,000 miles and since the crank case vent is built into the system and is another failure point I'm going to replace the cover.

And since I'm between houses with no garage or access to my tools…. I need to get a quote from another Indy shop. I've got belt chirping going on so I know I need to replace the belt and pulleys,. This isn't going to be a cheap visit I'm sure.

[TWO STEP TEX]

Aw hell, I hope it doesn't end up screwing up your crank seal. Mine was chirping a little at first, I managed to cut off the plastic pcv cap and install one I got off of Amazon. The chirp turned into a squeal, which is a symptom of a bad crank seal. I installed a Mishimoto catch can today and when I test drove the car, I couldn't get it to squeal. These BMWs are mysterious creatures.

[ferocity02]

I did my DCT service at 55K. It definitely didn't need it, thr fluid looked good relatively speaking. No improvement in shifting but it was good peace of mind.