Should the transmission fluid be changed on a 1998 Boxster?

[bill945]

Hi!

This is my first post and I hope that someone can help me with a question regarding my 180k service.

I'm the original owner of a 1998 Boxster, almost at 180k miles, tiptronic, all scheduled maintenance done on time.

My Porsche mechanic gave me the option of not changing the transmission fluid because:

a) At 180k, the transmission is beyond it's life expectancy
b) The clutches are probably worn down and when that happens it's most happy with the old fluid because with new fluid there's a small chance the transmission will not like it and start slipping.

So the question is change the fluid and take the chance it's going to start slipping or leave the old fluid in?

Thank you for any insight!

[JFP in PA]

Yes..............

[Smallblock454]

NO ......

So, put your popcorn out!

Regards, Markus

[alm001]

Originally Posted by JFP in PA

Yes..............

Originally Posted by Smallblock454

NO ......

Maybe.....

[cesarpeji]

Originally Posted by bill945

Hi!

This is my first post and I hope that someone can help me with a question regarding my 180k service.

I'm the original owner of a 1998 Boxster, almost at 180k miles, tiptronic, all scheduled maintenance done on time.

My Porsche mechanic gave me the option of not changing the transmission fluid because:

a) At 180k, the transmission is beyond it's life expectancy
b) The clutches are probably worn down and when that happens it's most happy with the old fluid because with new fluid there's a small chance the transmission will not like it and start slipping.

So the question is change the fluid and take the chance it's going to start slipping or leave the old fluid in?

Thank you for any insight!

Yes. change the trans fluid. will be okay.

[rick3000]

It sounds like the mechanic is thinking it is not worth the trouble because your transmission will fail soon anyway. However, it is entirely possible it will last much longer than he expects, and new fluid will help it last longer. So yes I would recommend changing the transmission fluid, but use the correct OEM fluid for a '98.

[911monty]

At this point your existing fluid is probably fairly loaded with friction material etc. This is most likely causing a fairly substantial pressure drop across the filter. Eventually the limited fluid flow will cause it's own issues. However a simple drain and refill will only change approx 30% of the fluid volume. So if you change it and you probably should, then in order to have fairly clean fluid you will need to plan on changing the fluid about 5 times in succession. Even then you will probably end up with approx 25% dirty fluid circulating. The problem is the torque converter holds around 11 qts of fluid and there is no way to get it out short of pulling the trans and torque converter. In short you will dilute 30% of the fluid 5 times.
Clutch packs might not like it but your valve body is going to love it. More info in the thread attached.

http://986forum.com/forums/general-discussions/61760-tiptronic-transmission-oil-change.html

[thstone]

Change the fluid.