DIY Tiptronic fluid flush of ATF cooler and lines
 

Use the search feature to find the links to Tiptronic ATF fluid change threads. But these procedures still leave fluid in the ATF cooling lines and ATF cooler.

According to the workshop manual draining and refilling the Tiptronic transmission is about 3.5L of fluid. The total system is about 9.5L. (These estimates seem high to me). There is more fluid in plumbing to the ATF cooling radiator and lines which is sandwiched with the oil cooler in front of the right front wheel.

In the workshop manual it warns "If the ATF is carbonized, or if there is sludge or evidence of lining abrasion in the ATF sump, it is not sufficient merely to repair or replace the gearbox; the ATF cooler and line system must be flushed with ATF."

The workshop manual then shows how you can use the ATF fluid device and M16 x 1.5 coupler to flush the cooler and the lines. Unfortunately I left my ATF fluid filling device in Germany so I had to recreate one in my garage.

The inlet and outlet lines to the cooler (19mm nut hydraulic fittings) are on the left side of Tiptronic transmission unit. In my case when I dropped the engine I had to disconnect these from the car. It appears to me in the workshop manual that you connect the flushing device to the lower hose and let the fluid drain out of the top hose.

My Tiptronic filling device is a cheap garden sprayer. It allows me to pressure the fluid and with the wand fill my tiptronic sump. I adapted this system by hooking up a 1/4" hose to the end of the wand and then purchased the right fittings to hook up to the Tiptronic cooling lines.

At www.mcmaster.com in the USA I bought the following fittings:

1 4936K158 1/2 NPT Female Adapter X M16 X 1.5 Metric Male
2 5346K44 Brass Barbed Hose Fitting, Adapter for 1/4" Hose ID X 1/2" NPTF
3 A few feet of 1/4" ID clear hose & 2 hose clamps

This allowed me to hook up to the M16 x 1.5 hydraulic fitting and then connect to a 1/4" clear tubing. I think the pictures below describe the setup and basic procedure. I hooked up my system to the lower hose.

This worked great. The last picture is a sample of the old ATF when I first started the flush and the a sample of the fluid draining at the end of the flush. I pushed about 4.5 L through the system. My car has 72k miles. Who knows when the fluid was last serviced.

Nicely done sir. I used my motive bleeder to simply pump about 4qts back into the pan after changing the filter, but this looks like you were really able to get a full fluid exchange.

My used ATF fluid with 76k miles on it didn't look too bad, but yours looks tired.

Tip fluid color
 

Not sure why the fluid is red? Do different tiptronics take different fluid? The OEM fluid I used ESSO and Pentrosi are both light brown amber in color and have a very unique almost cotton smell. This is on a 986 application though.

Hey Guys.

Resurrecting an old thread here. I'm about to do this oil change on my ´90 964 Carrera 2. According to the workship manual, although the transmission holds 9,5L, apparently only 3,5L is extracted when doing the oil change. Can anyone back this up? A flush is only necessary if there is wear resulting in thick, mushy deposits and in which case a new gearbox would be needed.

Now regarding the oil strainer. Porsche DON'T suggest replacing this - it's a strainer not a filter. ATF to be changed and strainer CLEANED every 40.000 miles is what is suggested in the manual. It also says "THOROUGHLY CLEAN THE STRAINER AND PAN - REFIT STRAINER WITH A NEW O RING. Part number for the O-ring is 943 307 041 00. I'd certainly prefer to go down this route, especially if you'd otherwise be replacing a stock Porsche strainer with an aftermarket one. Have you seen the prices of the Porsche OEM filter - ouch!!!

A quick question relating to the 6 x M6 hex bolts that hold the pan onto the underside of the tranmission. I'd expected to see copper crush washers with these, yet four of them have "retaining bracket" part ref. 943 321 161 01 whilst the remaining two have "retaining bracket" part ref. 943 321 161 00. Is it necessary to relplace these "retaining bracjets"? Do they have a sealing function as a crush washer would?

On my 1994 993 tip - about 5.5 quarts of old fluid drains out each time.
I put back approximately 6 quarts to get the level right according to factory measurement method.

Clean and inspect both magnets inside the pan.
OEM filter/strainer replacements are fine.

I'm still using stock retaining brackets. Have had the pan out about 5 times. No issues.
Don't think they have a crush washer sealing function.

You might want to consider changing your final drive fluid as well if it has not been done before.

I've been using Mobil Dex6 since the last change. I really like Dex6

Good luck

The brackets have no sealing function. My brackets had a bit of corrosion on them so I threw them into a tumbler for a few hours with crushed walnuts. You do need to replace the pan to case seal obviously. I also changed the strainer rather than cleaning it. Remember the manual says you should check the fluid level at 80 C. I don't have a hammer so I took the temp with an infrared thermometer from the pan and figured that was close enough. I did measure how much came out though - 3.5 liters was pretty spot on for me.

Thanks. In which case I'll pass up on ordering the 6 retaining brackets. I'm still going to stick with the old strainer and give it a good clean - if that's good enough for the factory, it's good enough for me.

Final drive oil change. That is something I'd like to do too, but haven't found any info on doing it. Couldn't see it mentioned in the workshop manual either?? Being a transaxle I would've thought it'd be the same thing??

Thanks, I haven't the proper kit either and thought of doing as you've suggested. That's great, thanks.

The final drive oil change is easy. Open the fill plug first so if you get stuck with that one, you can still drive the car. You need to remove the right rear wheel and you'll see the allen bolt on the final drive. That's the fill plug. The drain plug looks the same and is at the bottom. The drain plug has a magnet so look for metal on that to see if you have excessive wear. Torque to 30 Nm and use a washer on each. You fill, like most car gearboxes, until you see overflow out of the fill hole. Make sure the car is level. Unless you have a frozen bolt, this can be done in less than 2 hours.

Hey CJOENCK. That's a great help. I can see from PET the location of both the fill and drain plugs. They both need 900 123 118 30 aluminium sealing rings/washers - 22 x 27 - exactly the same as the crank case oil drain plug, so that's cool, I've got a bag of those. Nice to hear too that it's filled as you would normally fill a manual gearbox - no pumps needed, no getting it up to a predetermined temperature. 2 hours may even give enough time to have a sandwich break in the middle :-)

Do I use the same ATF fluid that I'm putting in the transmission?

No, the final drive does not take ATF fluid. It uses “regular” gear oil. The specs have changed over the years and there are different opinions out here. I can’t remember what I used off the top of my head but I’ll look it up. From the workshop manual....

https://cimg1.ibsrv.net/gimg/rennlis...83fac32aa4.png

I used Mobil 1 75W90...

Instead of a Motive bleeder, I used a $15.00 weed sprayer and attached a hose to the sprayer handle. That way I can add fluid with one hand while looking at the gauge. Zero stress and efficient.

https://cimg9.ibsrv.net/gimg/rennlis...06eeafb13.jpeg
I used a pump like this to fill my tip trans after reinstalling the trans and engine. Prior to the install I put one end of the cooler lines in a drain pan used low pressure air to clear cooler and lines

That's a really neat idea. Thanks.