1999 Boxster manual transmission fluid change

[Vidyashankara]

I am due for a transmission fluid change. I looked up the diy instructions and it's relatively simple. The part I am not sure of is whether the 5 speed manual transmission also has a filter inside. Upon draining the transmission, do we also open up the oil pan and replace the gasket and the oil filter like the automatic transmission?

Thanks for your help in advance,
Vidhu

[JFP in PA]

No, there is no filter, nor a removable oil pan. You drain it and refill it according to the service manual procedures to the correct fluid level.

[Vidyashankara]

Excellent! Thanks! Must be very straight fwd then!

[ltusler]

Be sure you can open the fill plug before you do the drain.

[thstone]

The most difficult part is finding the triple square socket!

Transmission Drain Plug Madness

[paulofto]

Originally Posted by ltusler

Be sure you can open the fill plug before you do the drain.

+1 . . Nothing like draining your fluid then not being able to refill it.

[Vidyashankara]

Thanks, I'll get the socket driver and will remember to remove the fill plug first

Just curious, why isn't there a filter for the manual transmissions?

The manual also says to change the differential fluid for the automatic transmissions. I am guessing this isn't done in the manual transmissions as well?

[JFP in PA]

Originally Posted by Vidyashankara

Thanks, I'll get the socket driver and will remember to remove the fill plug first

Just curious, why isn't there a filter for the manual transmissions?

The manual also says to change the differential fluid for the automatic transmissions. I am guessing this isn't done in the manual transmissions as well?

Because manual gear boxes are splash lubrication by the movement of the gears rather than by a pump, there is no filter. And a manual transmission is also the differential, unlike the Tip equipped cars.

[thstone]

The manual transmission is comprised of both the transmission and the differential in a single unit - so when referring to a manual transmission, we all really mean transaxle.

[Vidyashankara]

awesome thanks!

[Vidyashankara]

Hi Guys,
Just getting around to finish the job.

I was wondering if I can use good old Mobil 1 Synthetic 75w90 LS gear oil as the transmission fluid?

Thanks,
Vidhu

[Vidyashankara]

Capri Tools 1/2 in. Drive 16 mm XZN Triple Square Bit Socket-CP30055 - The Home Depot

IS this the socket used to remove the drain plug in the 5 spd transmission?

[thstone]

Originally Posted by Vidyashankara

I was wondering if I can use good old Mobil 1 Synthetic 75w90 LS gear oil as the transmission fluid?

Most of us use the factory fluid. Yes, its expensive but it seems to work the best. Here are a couple of links to previous discussions:

http://986forum.com/forums/general-discussions/30441-manual-transmission-fluid-best-brands.html

Transmission Fluid - really that hard?

[rick3000]

You definitely want to use the OEM Porsche transmission fluid, it is specific to the transmission, and people seem to have issues using non-OEM fluid. The PN is: 000 043 304 71. I do not think it is available in individual liters anymore, you have to buy a drum of it. However, Sunset Porsche sells it by the liter (they fill up empty/clean oil cans). You will need 3 liters, which runs about $80. If you try to buy it at the dealer, don't let them sell you anything other than that part number, it is not the same.

[Vidyashankara]

Thanks for the responses guys! I ditched my plans on using Mobil 1 and called the dealer based on your feedback.

However, like you mentioned, most of the dealers only had a 20L drum. One of the bigger porsche dealership had another PN for the manual transmission fluid based on the VIN i provided them. They had 1L bottles of that. The PN is 00004330549. I ask their service people and they said this is what they use on all their 986. Anyone knows whats the difference between this and the one posted above?

[Vidyashankara]

This was also $50 a liter. I bought 3 bottles today. My 5 speed transmission should take 2.25L of this fluid.

[Vidyashankara]

I did the fluid swap yesterday. Went well overall..

The old fluid looked very good. I was expecting black gunk to flow out, but it was nice and clear. It did have an odd smell.

Then I added the new fluid till it overflowed a bit. Then started the engine, let it run for a while in all gears, then i added more fluid till it started to leak out. Then I torqued the fill plug.

I thought it was easier to change gears immediately yesterday. But today when i took it out, it wasn't as smooth as yesterday after the change.. maybe takes a while to work?

I used PN 00004330549 for the transmission fluid.

[rick3000]

You overfilled it, it is supposed to be 11mm below the fill hole. See the DIY:
Porsche Boxster Differential / Manual Transmission Fluid Change - 986 / 987 (1997-08) - Pelican Parts Technical Article

[Vidyashankara]

>>>Replace the bottom plug on the transmission, but don't tighten it too tightly (18 ft-lbs or 25 Nm maximum). These plugs do not have a tendency to leak (transmission oil is thicker than engine oil). If it does leak later on, you can always tighten it a little more. Now, add transmission oil to the case. The best method of doing this is with a hand operated oil pump. These are available from most auto parts stores and attach to the top of the plastic transmission oil bottle. They work very similar to the liquid soap dispensers you find in most bathrooms. Pump the transmission case full of fluid until it just starts to run out the filler hole. Replace the filler plug and clean up the few drips that might have run out of the hole. Tighten down the filler plug in a similar manner to the drain plug.


ISnt that to check the fluid level? The procedure asks to fill the oil until it overflows?

[Anker]

The instructions for the 5 and 6 speed transmissions are different.

The 11mm below is for the manual 5 speed transmission.

The fill to the bottom of the fill hole is for the manual 6 speed.