958TurboS

I know there are stickies on the DIY ATF change. I'm more interested in everyone's thoughts on the Porsche recommended service interval of 160k miles or 16 years.

I've got a 958.1 CTTS w/ 56k miles. But I do tow a travel trailer a few times a year. I'm planning on changing the differential fluid and transfer case fluid, but I'm torn on whether I should do the transmission fluid too.

Thoughts?

Thank you

AnAlbumCover

I think no one will say you shouldn't change it.

Maybe the better question is, what is your apprehension to changing it early?

RhinoComp

Certainly wouldn't hurt to do it as a part of your 60K service, but probably not ultra-required by any means unless you're having harsher shifts. I'm going to be doing my transmission along with both differentials as a 100K service here at the end of the week. Mine is still shifting pretty nicely at 96K miles, but a fluid change might reveal that it could be a lot better!

958TurboS

Great question. Primarily I just don't want to mess with it if it's not needed. I do have some jerking at low speeds, but I think that's due to the transfer case.

And if I'm completely honest, I suppose I'm trying to find reasons not to do it because this will be my first time doing that procedure on any car, and it's kind of intimidating given the make and model.

958TurboS

Will this be your first time doing the AT fluid and filter? Let me know how it goes and what you use to measure the temperature of the fluid in order to get the correct fill amount.

RhinoComp

Tell yourself it's a Toyota transmission (it is) That said, it's not a super complex or expensive procedure at a good indy shop. I'll confirm the final cost after mine's finished this Friday, but I was at least verbally quoted under $500 including parts for the whole transmission fluid service with OEM filter and fluid. At that price, it's hardly worth my time and effort to get it done myself. And this is a highly reputable shop in Seattle too so not some chop shop with low prices.

958TurboS

That's a good point. I need to find a new indy shop in my area and check the cost.

I just hate spending the money on a one time service when I can spend less and get new tools out of it .

RhinoComp

Also very true! Check out Blauparts. They've got a full service kit with an OE filter and Ravenol fluid, but also sell a couple of nice pumps and adapters for our transmissions fill port. On top of that, they have a really excellent DIY guide with pictures, addresses what to do at temperature, etc... basically all of your concerns. May even have a YouTube video as well. I was going to be purchasing said kit and following their guide, but since I've got a big cross country road trip coming up I just have other items I'd rather put my time towards over learning as I go with this task.

Also check the Rennlist Marketplace if you do want to go that route. I actually recall seeing that someone was selling the exact fluid kit you'd need with extra fluid at a pretty hefty bargain. Can't remember what I searched last week that I saw it, but it was recent.

EDIT: Found it https://rennlist.com/forums/market/1348552 Really good deal if you're wanting to do it yourself since they're actually selling the fill port adapter and a fluid pump too (assuming it's still available of course)

958TurboS

Thank you for digging that up! I'll have to confirm it's compatibility but looks like a great deal! I was already looking at the kit on Blauparts and was expecting to spend $550 for the kit and simple tools.

Gus B.

FCP Euro too has a transmission service kit that you can take a look at. I used it on my '13 GTS and had a local indy shop (owned by the ex head mechanic at the local dealer) and though my vehicle only had 45K miles, it was 10 years old and I rather know there is some fresh fluid in there to make sure it works as good as it gets. Took advantage of the work being done to have the transfer case oil changed too (with Ravenol from Blauparts).

Jfjeaj

I think no one will say you shouldn't change it.

958TurboS

I called the local dealership and a local indy shop.

Neither wanted to provide an actual price, which is odd for a maintenance item. I guess that's how rarely these are asked for?

The dealership's estimate was $1000.
The indy shop's estimate was $700 - $1,400.

At those costs, I'm 100% doing it myself.

kari

Did my diff, transfer case and atf fluid changes earlier this month on a 2014 base with 115k km (~72k mi) .. same OC8 series transmission..

If there is anything i regret not changing earlier its the diff fluids .. felt the fluid was way darker than expected and didnt feel as viscous as the new 75w90 I put in. ( open diffs at the front and rear).

Same about tc fluid. Maybe just in time but id want to do that every 24-30k km in the future.. my tc was replaced earler under warranty and only has 38k km and ~4 yrs and the fluid was again quite dark. Used ravenol dtf1...

Of the fluids the atf was the cleanest. Was dark but could still see a bit of red.. i did not do a full flush but a pan drop and filter change.. ravenol t-ws for the fluid and bought the hengst filter and gasket kit from fcp.

I felt improvements in gear shifts ( not that i had issues to begin with) which could be the atf or tc or both... Temperatures or mileage didnt change much..

MDTXCA

Is this the kit? I saw reviews that you need to buy 2 more liters. Did you use all 8 liters or more?

Looking to see if I need to add 2 more liters to this kit.

https://www.fcpeuro.com/products/por...kt#description

MDTXCA

Did you not want to get this Ravenol Kit? https://www.blauparts.com/porsche-ca...hange-kit.html

I'm thinking either this or the FCP Euro kit with Liquid Moly.