Transmission fluid recs

[Datsom]

Hi all,

Been a while since I've been on to say hello!

Winter typically = hibernation.

My 924S is under cover, just waiting for some warmer weather so I can get out there and change out the water pump and hoses, plugs and wires, etc. After some trepidation, I decided I'm going to tackle it myself. I've been watching edredas on youtube and feel like, while it is somewhat complicated, it is doable with the right tools and a zen approach.

I've been using this quiet winter downtime to assemble stuff needed to get the above plus other jobs done. One of the things I think is worth doing is a tranny fluid flush. That's why I'm writing today.

On the 924S (5 speed), is a transaxle flush a straightforward job? Any tips for flushing out the fluids (i.e. should i put in fresh, drive it for a few days, and then flush it again)?
Lastly, any preferred viscosities/producers? Amsoil? LiquiMoly? Factory? Car has 100000 miles and likely the associated wear. Unsure of the history of fluid changes. Roughly how much fluid is required?

Any thoughts greatly appreciated.

Warmest,
S

[Dmitry S.]

I'm not sure that you need to "flush" the fluid. Drive the car on the freeway for 20 minutes to get the gearbox oil to a higher temp and as long as the car is level when you raise it up, you'll be able to get all the old fluid out. Maybe cars with an oil cooler loop would benefit from a flush, but I personally think it's a waste of money.

The transaxle takes 2.6L of fluid. I believe the manual calls for 75W-90 gear oil.

I've tried a number of oils. Porsche OEM. Redline. Mobil 1. My favorite BY FAR is Swepco 201 and 202. Shifts are just so much smoother, and the transmission is quieter.

The job itself is very easy and requires just one tool - a 17mm allen. Make sure to remove the top one (fill) first before draining. Then use a fluid pump (can find one for ~10 bucks at any auto parts store) to fill up the transmission until fluid starts to slowly overflow from the fill plug. This ends up being a bit more than 2.6L, but it shouldn't hurt anything. Torque the plugs to 18 ft / lbs.

http://www.clarks-garage.com/pdf-manual/trans-06.pdf

[Datsom]

Awesome advice -- thanks Dmitry. Of course!!! Clark's garage! Totally slipped my mind on that.

Never heard of Swepco. Just looking into it now. In the absence of being able to find it, is there a second place, in your thinking? I'd like to try it, though. Will seek it out.

Thanks again,
Stephen

[Datsom]

Never mind. Looks like our friends here at Pelican carry it. Wonder if it's not too late to add some to my order.

Thanks again!
S

[RedCarGuy]

I used Redline MT-90 on my car a couple years ago at 125k miles and very happy with it since. Just like engine oil, you'll hear a lot of different opinions on this.

I used a cheap hand pump to fill it as space is tight around there.

[Datsom]

Good point @redcarguy! To prove the point, I definitely have my own thoughts on motor oils, so yeah, it would stand to reason. Hand pump -- yes. Thank you!!

[jjeffries]

I have yet to drive my project 924S but had the transaxle out during the over rehabilitation. I drained out whatever was in - didn’t look bad - and refilled with mineral Kendall, which I use in my SC’s 915 unit. We shall see.

John

[Datsom]

Thanks @jjefferies.

Fluid has been ordered here at Pelican -- Redline 75W-90 GL-5 Synthetic High-Performance Gear Oil. Swepco was something like a two week wait and I didn't have that option, unfortunately. I will get Swepco for the next change, for sure.

Keep us posted on the Kendall.

Stephen

[OK-944]

I've actually used Mobil-1 75/90 with good success, but am thinking of going back to either Redline or Swepco for my current rehab...just because!

I do like the original old brass threaded trans seal plugs - I trust them to seal better than the new steel ones.

Some folks use plumbers teflon thread tape to help seal the plug threads...which I might with the newer plugs...but the brass ones seem to seal up nice. In certain situations, plumbers tape can actually compromise a seal.

As far as a flush (I've heard that kerosene works well for this, anybody?)...maybe if the old fluid is super-dirty (and/or old), or has metal shavings present. Then again...metal shavings might indicate the need to open up the trans and take a closer look!

[jjeffries]

No kerosene!

John

[Datsom]

Hey @OK-944 -- helpful reminder insofar as keeping an eye open for shavings. I recall, before garaging the car for the winter a pretty unfortunate whine at highway speed, which changed with on/off throttle input (maybe input/output shaft bearing in the tranny?). Not sure at this point, but first order of business is flush those fluids. It's entirely possible it's never been refreshed.

@jjefferies -- got you on the kerosene. Will avoid it. But will be back to you (and the forum) for guidance if I can't sort out the whine! (Admittedly, we're a way's off from that, though! )

Warmest,
S

[OK-944]

Hmmm...then maybe diesel? I remember a discussion awhile back about tranny flushing, and also that kerosene was mentioned - but yeah...probably would be hell on seals, etc.

Maybe just a sacrificial fill up of tranny fluid - drive, drain, and refill? Sounds about right.

[Ernie944]

Originally Posted by Datsom

Thanks @jjefferies.

Fluid has been ordered here at Pelican -- Redline 75W-90 GL-5 Synthetic High-Performance Gear Oil. Swepco was something like a two week wait and I didn't have that option, unfortunately. I will get Swepco for the next change, for sure.

Keep us posted on the Kendall.

Stephen

Forget Swepco,you'll be very satisfy with Redline 75W-90 GL-5 Synthec.Had it both in my 944 & 968 drove them for years with no problems.

[Datsom]

There you are @Ernie944!! Good to read you. Bonne Annee! (Is it too late for that?)

Great to get your thumbs up on the Redline. But, I will try the Swepco as well down the road sometime.

I've been meaning to write to you directly about a belt tensioner. You don't have one in NB that I can borrow for my belt job when I get around to it, do you?

Otherwise, I was thinking I might have no choice but to do the Arnworxx, which at $180 is miles ahead of the $650+ for the Porsche tool on Ebay.

I suppose that's a new thread, though. LOL!

[Rasta Monsta]

Redline MTL is great. Also, BE SURE TO LOOSEN THE FILL PLUG PRIOR TO DRAINING!! If you can't get it off after draining (happens) you'll be in a jam.

[Datsom]

Thanks @RastaMonsta -- will do! I could see how that would be a problem. Appreciate the tip!

[walfreyydo]

Mobil 1 synthetic 75W-90