[AWSAWS]

Hi Guys,
does anyone have any experience in working in fabrication with metals?

I feel I'm in need of a metal sump on my DCT transmission because it is not handling high temperatures very well. I don't believe a plastic tray can radiate the heat very well.

I am wondering, if I purchase another plastic sump, how difficult would it be to cast a copy in aluminium?

Would a billet aluminium option be too costly?

There are some available on the market but at $1000 plus shipping and duty and tax it's just too expensive.

This is the tray

https://www.ecstuning.com/b-genuine-...n/28107842385/

The challenge I suppose is making sure it has the correct size threaded holes etc to attach to the transmission. Also that it can tolerate the pressures involved.

[lloydie]

Actually modern plastics are pretty good - the body of the transmission will radiate more heat than the sump will. Its true though, that as its in the airflow you could add a finned sump and take advantage of the cooling that offers. However you would be far better off with a dedicated transmission cooler.

Casting a one off would be roughly £1k when you factor in the tooling costs. The issue you will likely have though is that the casting will be porous and will leak through the material. The best way would be to make dedicated casting boxes up, as they are used for batch production - though this will be costly. The finish of the casting as it comes out of the box will not be sufficiently good to fit to the car. It will need to be machined to remove the flashing, cut threads where needed, but most of all to give you a good flat surface to bolt to the transmission. This will likely be another £200-250.

Billet would be an option, but the measuring of the OEM sump will be time consuming, to transfer it into a drawing accurate enough to be machined from. Maybe £5-600 ? Plus then there's the material cost and machine time to add on, maybe £2-300 more ?

Assume there is no OEM option for a metal sump ? The 335D shares the transmission with a Range Rover which had a metal sump as standard and they are interchangeable.

[Digitalize]

As said Casting will be far too expensive, you'd be better off having it machined out of a solid block of metal such as aluminium. You need to ask why they're plastic in the first place really.

Find somewhere that has a 3D Scanner and a CNC machine, ideally someone looking to earn a bit of extra money after hours to keep costs down.

[GATORB8]

What about an upgraded trans cooler, something like this:
https://www.redline360.com/csf-trans...0-e92-e93-8042

[Dann]

Casting is pointless as you would have to machine it all afterwards anyway.

I can tell you know that a machining of that size will be a few hundred quid, and then getting someone to CAD it all up will be just as expensive. (unless you are qualified/skilled enough to do it yourself)

I've got some parts being machined at the moment for work and a small block of aluminium (50mm Diameter and 30mm high) is over 80 quid a pop.

You'd be surprised how good modern plastics are, what makes you think that it can't handle the temperatures?
The sumps job isn't to dissipate the heat, that's a job for heat exchanger or cooler. The sump is just there for the fluid to sit in for pickup by a pump.

[Chappers 71]

If your getting DCT overheat it could be down to low fluid or possibly with your trips to the pod & all the power your running the clutches may need replacing

[AWSAWS]

Guys,
thanks for all of the feedback. The reason I'm concerned about it not taking the heat is that people say they warp under the heat. I'm already putting twice the power through the transmission than it was taking stock.

The dedicated cooler is definitely an option to consider.I need to double check my car doesn't have a cooler already. The cooler system doesn't show up on realOEM but it doesn't show up on any of the M cars either that definately have them.

I already replaced the sump once when it ws covered in fluid and sometimes mis-shifting. Now my sump is covered in oil again. On another forum I have been told that the DCT will vent fluid under some conditions, to relieve pressure build up I suppose. Obviously heat increases pressure also.

I do suspect the fluid could be low. I've not had any symptoms of bad shifts but I am concerned how muchfluid has been lost in the 2 years since I had it re-done.

I have 3 litres of the Pentosin FFL-4 to do a top up. My jack isn't big enough to raise the car high enough on 4 jack stands to do the job so I'm trying to work something out.

I'm actually considering applying essentially a heat sink to the plastic sump with silicone glue to better radiate the heat. I have the high temp silicone glue. I've got some PC heat sinks but I could use some metal strips.

There are GTR sumps for £600 which I could stomach but $1000 + other costs is just too much.

I realise the metal transmission unit itself will be a great radiator. I've removed the undertray at the moment to get a look at the transmission and that would greatly increase air circulation as well. Although it does become more prone to damage.


I get what you guys are saying about plastics withstanding heat. I'm still amazed the oil filter has a plastic cap. That thing really heats up after a spirited drive!

[AWSAWS]