I changed my transmission oil...
 

I've had the stuff to do this job for several weeks, and finally got it done last night. I did an motor oil change, tranny oil change, and brake fluid flush all while I had it up in the air.

For the transmission I used Redline MT90, which is a 75W90 GL-4 rated synthetic. My car's 3rd and 4th gears were little stiff when cold, but after warming up would shift nicely. This morning's drive with the MT90 in there proved to be a big improvement! The shifter was about half as balky going into 3 and 4 as it was before the oil change, and just seemed slicker overall. I'll be paying attention over the next few days to see if it continues to get better, but with the improvement I've seen already, it was well worth it! An easy DIY project.

Red Line Products are superior. Pricey too!

Thanks for the post.

Hi,

The fluid you chose does make a difference, but a caution of just buying the most expensive.

Different Transmissions respond differently to the various Fluids available. I use Redline MT90 in the 5-speed box in my Esprit and it works better than Mobil1 or Valvoline Synth for this Citroen SM sourced tranny. Been using it for almost 10 years.

But, Redline MT90 does not work nearly as well in my '71 240Z 4-speed. The shifting is less smooth and the synchros are noisier, the best fluid for this box is the Valvoline.

There are several variations of the Boxster Tranny and you may find that different fluids work with varying degrees in each. Hope this helps...

Happy Motoring!... Jim'99

This is a bit of an old thread, but I want to change my 5 speed manual transmission fluid this weekend and wondered how much I should buy. Anyone know?

Hi,

You want 2.25L or 2.4 Qts. of Hypoid Gear Oil SAE 75W90. The manual tranny shares the fluid with the differential, so no need to change that. Synthetic is good, the Red Line is supreme. It will make the shifts crisper and smoother.

You need to fill the tranny to 11mm below the Fill Hole. The easiest way to measure this is to take a piece of wire, put a 90° bend in it and cut off the bent end to 11mm. Then, insert the wire into the fill hole to be sure that the level just touches the bottom of the wire. Hope this helps...

Happy Motoring!... Jim'99

Thank you, Jim! Yoda man :cheers:

yay..i might just do that entire change all togwehter just like wahy t the OP did....

thanks for the advise jim!!

Redline advised me that the proper fluid for the Boxster S (6-speed) is their 75W90NS (no slip) fluid, so that's what I used when I did mine. YMMV. From reading the bottle's label it seems to meet the requirements for trans fluid as spelled out in the Boxster S manual.

Anyone running Red Line engine oil (5W40)? I am thinking about trying it at the next oil change.

Red Line makes perhaps 5 different tranny oils. They will advise if you contact them.

Here is a link to the Red Line tranny fluids/oils:

http://www.redlineoil.com/products_gearlubricants.asp

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What type of apparatus do you use to raise your Boxster?

It's an easy job to do with the car simply on ramps in the rear. I did it on an angled driveway and leveled the car before checking the fill level.

Anyone have a write-up D.I.Y. with all the necassary tools required?

Do a search on Renntech. There is a transmission fluid change procedure linked from there. Basically the only "special" tool you need is a large (10mm?) hex socket for the drain and fill bolts.

All I could find is this;
http://www.renntech.org/forums/index.php?showtopic=5155&pid=25632&mode=threaded&s how=&st=&#entry25632

That doesn't have the location of where to drain or fill the oil. Anyone know where I can find that?

Thanks! Now this will be my next D.I.Y.

Is this the right tool to remove the oil filler and drain plugs?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=008&sspagename=STRK%3AME WA%3AIT&viewitem=&item=180039535374&rd=1&rd=1

what oil would you guys recomend for a 99 5 speed? i went to a shop that works on german cars the other day and they quoted me $120.00 to change the oil, they said it took 2.25 liters of porsche tranny oil @ $30.00 per liter so i think i will change it myself but i dont know wich oil to use. can someone recommend an oil that i could easily find at pepboys or wallmart???