DIY: 6MT Transmission Oil Change

kaiv wrote

I'm gonna guess track time does that. The fluid sees high temps there and breaks down faster. Which is why I change all this stuff much sooner than BMW's recommended intervals.

Transmission always felt great although it does feel a little smoother since

And I thought my fluid was dark... got nothing compared to yours. But mine did shift a bit easier. Always had issues going from 4th into 5th, and fresh fluid definitely helped.

Really simple DIY btw, definitely worth doing.

Were you able to fill up the tranny quickly with the spray bottle? Thinking about how much liquid shoots out from a spray bottle it seems like it would take forever?

And is the consensus you don't need to activate the pump to try and drain out the remaining fluid? You just need to drain it from the drain hole and refill like a standard tranny? Thanks

dreamspeed wrote

Were you able to fill up the tranny quickly with the spray bottle? Thinking about how much liquid shoots out from a spray bottle it seems like it would take forever?

And is the consensus you don't need to activate the pump to try and drain out the remaining fluid? You just need to drain it from the drain hole and refill like a standard tranny? Thanks

It wasn't quick but it got the job done. You can buy a transfer pump for $15-20 at a local autoparts store that will probably be quicker. I rather spend the time than the money but that's just me. Both ways work fine.

The amount of fluid in the pump and transmission cooler is about 250 ml according to a previous post. That is about 10% of what the transmission takes total in fluid. I did not activate the pump but my fluid wasn't that bad. Whether or not activate the pump, I would use your own discretion and consider taking it to a shop or dealer since there is no home tool to activate the pump at the moment. If it has been well over 30K miles or driven on many track days then getting that last bit of fluid out might be a good idea.

If you don't find the pump activation necessary, then drain and refill like a standard tranny.

Good luck with everything.

Ok, thanks.

I actually have the pump where there is a tube that goes into the transmission fluid container and another tube that goes into the tranny. It moves the fluid quickly but it ends up spilling or I have to have someone hold on to it while I pump.

I like the spray bottle method because it seems "cleaner."

dreamspeed wrote

Ok, thanks.

I actually have the pump where there is a tube that goes into the transmission fluid container and another tube that goes into the tranny. It moves the fluid quickly but it ends up spilling or I have to have someone hold on to it while I pump.

I like the spray bottle method because it seems "cleaner."

That's what I used, made a mess, especially when I was working on the diff fluid. The hose kept popping off and I lost a bunch of fluid. And as we all know, OEM diff fluid with FM = $$$$. That small puddle of it = steak dinner

FYI, I didn't bother activating the pump. No problems after 1k mile trip.

Flushing the transmission and cycling the pump is really easy. You don't need any fancy special tools. The pump has a connector with a wiring harness plugged into it. This harness has a brown wire and a red wire. The brown wire is connected to the ground. The red wire is connected to the +ve terminal of the battery via the car's computer. When the oil gets hot, the computer completes the circuit to activate the pump.

The dealer cycles the pump by completing this circuit via their scan tool. But you can MacGyver your way around this problem. All you have to do is directly connect the +ve battery terminal to the red wire bypassing the car's computer control. All I did was unplug the connector, and take it apart. I then piggybacked a small old wire onto the red wire and reassembled the connector and plugged it back in. The other end of my piggybacked wire was loose and hanging out of the connector. Then I got booster cables, connected one end to the +ve terminal under the hood, and touched the other end of that cable onto the exposed end of my piggyback.

After you drain the transmission oil, you leave the drainplug off and activate the pump for 30 seconds. This drains the oil in the cooler and lines. Then tighten the drain plug and fill the gearbox with 2 L of oil. Close the fill plug and cycle the pump again for 30 seconds to refill the cooler with new oil. Then open the fill plug and top off the oil till it flows out of the hole and tighten the fill plug. And that's it.

Using this method I was able to change about 2.5 L of oil, which I believe is a complete flush.

^I was thinking of this too but I didn't know how many volts and the current draw the pump actually takes. Do you think it's safe for the pump to be directly collected to the +ve terminal under the hood without frying?

e92zero wrote

^I was thinking of this too but I didn't know how many volts and the current draw the pump actually takes. Do you think it's safe for the pump to be directly collected to the +ve terminal under the hood without frying?

Yes. Totally safe. It's just a pump, no different than the air pump that comes in the mobility kit in the trunk. All it needs is 12V direct current. The only problem i had was that my piggyback wire was probably too thin. The terminal in contact with the booster cable did get a bit hot. So I was cycling the pump more like 5 seconds on, 10 seconds off. But the total cycling time was about 30 seconds. I would have used a thicker wire, except that I didn't have one, and also the plastic harness for the connector is a tight fit and I doubt a thicker piggyback would have fit onto the connector.

What is the difference between turning on the car, which activates the pump and flows fluid, vs activating the pump via DIS?

jjw2331 wrote

2 x Screw Plug with Gasket Ring (part#: 23117531356)

One must replace the entire plug/bolt? The "gasket ring" (a.k.a. washer right?) isn't a separate piece?

Thanks

DavidZ wrote

One must replace the entire plug/bolt? The "gasket ring" (a.k.a. washer right?) isn't a separate piece?

Thanks

BMW TIS only says to check oil screen ( replace if necessary), and replace sealing ring when installing

As for the fill and drain bolts, it says to clean and screw in.
Doesn't even say to change the sealing washers.

Are there separate washers for the drain and fill bolts though? I was looking at the brake line parts diagram recently and it looks like there aren't any washers between the mating surfaces there either. I'm just wondering how there aren't any leaks? Modern tolerances I guess?

DavidZ wrote

Are there separate washers for the drain and fill bolts though? I was looking at the brake line parts diagram recently and it looks like there aren't any washers between the mating surfaces there either. I'm just wondering how there aren't any leaks? Modern tolerances I guess?

The drain and fill plugs have rubber gaskets around the inner flange. No washers. Same idea with the differential drain and fill pugs.

You can reuse the plugs, but I replaced them just because. I listed the parts for others who want to replace them in the DIY.

Majin Buu wrote

Flushing the transmission and cycling the pump is really easy. You don't need any fancy special tools. The pump has a connector with a wiring harness plugged into it. This harness has a brown wire and a red wire. The brown wire is connected to the ground. The red wire is connected to the +ve terminal of the battery via the car's computer. When the oil gets hot, the computer completes the circuit to activate the pump.

The dealer cycles the pump by completing this circuit via their scan tool. But you can MacGyver your way around this problem. All you have to do is directly connect the +ve battery terminal to the red wire bypassing the car's computer control. All I did was unplug the connector, and take it apart. I then piggybacked a small old wire onto the red wire and reassembled the connector and plugged it back in. The other end of my piggybacked wire was loose and hanging out of the connector. Then I got booster cables, connected one end to the +ve terminal under the hood, and touched the other end of that cable onto the exposed end of my piggyback.

After you drain the transmission oil, you leave the drainplug off and activate the pump for 30 seconds. This drains the oil in the cooler and lines. Then tighten the drain plug and fill the gearbox with 2 L of oil. Close the fill plug and cycle the pump again for 30 seconds to refill the cooler with new oil. Then open the fill plug and top off the oil till it flows out of the hole and tighten the fill plug. And that's it.

Using this method I was able to change about 2.5 L of oil, which I believe is a complete flush.

What tools are available on the market to activate the pump and most importantly what will work best with our cars. Thanks.

jjw2331 wrote

The drain and fill plugs have rubber gaskets around the inner flange. No washers. Same idea with the differential drain and fill pugs.

You can reuse the plugs, but I replaced them just because. I listed the parts for others who want to replace them in the DIY.

Are you sure? I know the diff has a o-ring on the plug, but im not sure the tranny drain and fill is the same.

aussiem3 wrote

What tools are available on the market to activate the pump and most importantly what will work best with our cars. Thanks.

http://bmtechnic.co.uk/

You get the cable and the software. You can access DIS to activate the pump I assume.

Bagelfast wrote

Are you sure? I know the diff has a o-ring on the plug, but im not sure the tranny drain and fill is the same.

pretty sure.

But here's a pic to show you:

jjw2331 wrote

pretty sure.

But here's a pic to show you:

Yes your correct, I was thinking it was the same as my M5. In that case I would most def get a new plug that comes with the o-ring installed, just like the diff change. Even tho BMW doesn't say to do it, for 7-10 bucks, its worth the change.

Bagelfast wrote

... You get the cable and the software. You can access DIS to activate the pump I assume.

I have Bavarian Technic software and cable. I think it does a similar job with its activation for certain modules. I will check and post back. Thank you.

Anyone know if this would work?
http://www.turnermotorsport.com/showproduct.aspx?ProductID=1827&SEName=pentosin-mtf2-manual-transmission-fluid-1-liter-e46-e39-z3

After reading through several threads I've decided to go with Redline MTL for my transmission oil change.

Seeing as how I wouldn't be able to get all the old fluid out 100%, would it be an issue if the new Redline MTL is mixed with whatever is leftover of the MTF-LT2?

Since both fluids seem to be similar i'm assuming it shouldn't be a problem? Thanks

dreamspeed wrote

After reading through several threads I've decided to go with Redline MTF for my transmission oil change.

Seeing as how I wouldn't be able to get all the old fluid out 100%, would it be an issue if the new Redline MTF is mixed with whatever is leftover of the MTF-LT2?

Since both fluids seem to be similar i'm assuming it shouldn't be a problem? Thanks

Shouldn't be a problem as long as you are sure both fluids are similar.

The tranny pump is electric, it activates at a certain temperature of the oil.

After initially filling the tranny to the fill hole. Bolt her up, take her out for a drive until everything is nice and warm or around 20-30mins.. By this time, the electric oil pump for the tranny would have activated. Then you can go back, and recheck the level.