TerrestrialFlyte

Your comment about blowing out internal seals as me a little bit concerned. I did use the proper fill port. It was the lower one towards the front of the car. When I filled it up at one point there was some dripping out, but I think that was when I was on my second bottle and there was just some spillage from the pump. I’m wondering where the extra fluid might go if there was an internal seal blown out.

4Driver4

The transmission is vented. I'm not understanding the mechanics behind the "blow out the seals" comment.

Petza914

I'm not a tramission guy so maybe it's just aiomatics that have internal seals that can be damaged by too much fluid, but I would guess internal pressure from too much fluid could whip the oil or create additional drag, or maybe it's fine.

I'd look at that video I posted and see if you used the correct fill hole. If so you should be good. If not, take out the correct fill plug and let any extra drain out.

TerrestrialFlyte

Thanks, Petza!! I watched a few videos myself and checked out the DIY thread. I definitely used the right fill hole and was surprised when fluid started flowing out of it. Just feel like I didn’t get the expected drip from the same fill hole when I filled it back up with PTX. I notice improved shifts. Took it out for a 2 hour drive on Sunday and didn’t notice any negative effects. I’ll double check underneath to verify no leakage. But it seems if it’s vented then maybe expanding fluid from an overfill wouldn’t cause any issues.

Bruce In Philly

2009 C2S 178K

Odd, my manual denotes "approx. 3.17 quarts / 3.0 liters transmission oil Mobilube PTX Formula A (SAE 75W-90) GL 4.5" . I find this "approx" odd in that these transmissions should be all the same. Mine takes a tad over 3L to start dripping out of the fill hole but then, I am never sure the car is perfectly level on the rack. We like to be perfectly accurate, but I am not sure there is such a thing given the impossibility of being level.

I feel you should be changing this fluid every 35K miles or so... I think our transmissions are not all that robust and there is wear going on in there. But that is another thread discussion...

Once, a tech filled mine from the top hole. My indy at the time hired a tech from the local Porsche dealership... I guess this was the first .2 he filled. I gave him the fluid and he came back and said he needed more.... hmmm.... I went back and saw he used the top hole. Good news is that the top hole is just that, it is not a passage to some other chamber. He opened the lower hole, and put in an allen wrench ("L") and saw the level was just under the thread. I was fine with that. For my next fill, I purchased an extra litre and added until it dribbled. Honestly, I don't think it matters as precision is not needed... especially when the manual denotes "approx".

Peace
Bruce in Philly (now Atlanta)

TerrestrialFlyte

Good idea, Bruce. I’ll just pop it off and stick and Allen wrench in there. I tried it with my pinkie, but apparently that’s too fat. I couldn’t tell if it was wet from the fill plug threads when the old fluid drained out/spillage when I refilled it or if I was actually properly filled up.

Floyd540

Once you have drained out all of the old fluid, just refill it with the 3 liters of PTX that you bought. If you did not spill any of it then you are done. It is a splash and hope lubrication system, not very sensitive to fill level. While on the subject of MT, you can remove BOTH side "fill" plugs and fill from the top one. Any overage will flow out the lower one. That is how it is supposed to be done. Use PTX in these Asian gearboxes. We all use Redline in our other cars (BMW) but be advised that PTX is the one you want for these 997 boxes. The triple syncros on the low gears know what they like.

ahyiah

Good to know, I'm planning to change my transmission oil soon and I also have a numeric shifter installed (no cables though). I always felt that my shifter was a bit notchy compared to my old BMW Z3 M Coupe, but I always just chalked that up to differences between the manufacturers.

groovzilla

Changed my MT transmission fluid and Front differential fluid (C4) last month.
Good idea to use recommended fluid for front differential which is pricey.

TerrestrialFlyte

This is what my brain was slowly piecing together and makes sense. Although I’m only buying 3 liters of it anyhow. If I had drum of it like a dealership, maybe I’d be more likely to take that approach.

ahyiah

Question, I want to change my front diff fluid as well. I've bought a replacement plug for the transmission housing but I can't seem to find the plug for the front diff. Are they the same part (as in part number, not literally) ? Thanks in advance.

997Fanatic997

My Indy changed the gear oil today. Night and day difference as I was experiencing notchy 1st and 2nd gear shifts. No longer. $130 well spent.

Chalkboss

Changed mine too today using PTX and adjusted shifter cables. Shifts like butter now. Oil coming out was a little dark. Shifter was only out by one notch on one side. 60,100 miles.

Edcantera

Is the PTX a lot better than the factory fluid?

Petza914

I think PTX was the factory fluid. Problem is it wears out. I'll be changing mine every 30k miles or so, but only with PTX.