fivefathomapple

Thanks Todd! I mentioned to the service manager that many people were having luck with the Ravenol and he said that makes sense and didn't know why Porsche hasn't considered that. He also told me that they have had several 2017 models starting to come in with TC failures. So seems like the majority of the problems started in 2011 and now are confirmed up to 2017. That's a strong 7 years of failures. This is approaching IMS scenarios lol. I wonder if I ask to keep the failing TC if they will give it to me?

Mega Man

Fivefathomapple, good idea asking to keep the old TC but I would bet they're required by Porsche to keep it. I bought mine just out of warranty, one year and 2500 miles too late. I wasn't even aware of the TC issue when I purchased it, thought the bumpy acceleration I felt was either the new tires they had installed or the road in front of the dealer LOL😆.

deilenberger

Actually the moisture problem certainly has validity. Some of the people who rebuilt their own transfer cases have reported rust in the multiplace clutch pack, not excessive wear - but rust. The efforts Porsche took to correct their original flawed design (where a vent below the transfer case would capture water, throwing it at the spinning front driveshaft CV joint, which happily threw a bunch of it up to where the vent for the TC is located) is an indication they believed it was. I have been told (service adviser) that the fluid has now been added to the intermediate service listing (30,000 miles).

I don't think you can compare used stock TC oil and new TC oil from a different manufacturer and make a valid comparison that one is better than the other. It would have to be a comparison between equally used oil (difficult to accurately repeat all driving on 2 cars) or between two fillups with new fluid, I suspect your change interval is perhaps a bit excessive, I've gone to every other oil change (about 10,000 miles) or annually. Except for the expense of replacement plugs for the case - it's not a hard or expensive job. I can do it on my '11 Turbo by putting the suspension in the highest mode, and wiggling like a fat worm under the car. Piece of cake basically.

I'm on my original TC at 103,000 miles now - and it seems to be working just fine. If I ever get around to it, I'll add some sort of high-vent to the case, right now I avoid driving in deep water.

fivefathomapple

Hey Don, great info! My dealer said Porsche has not informed them to add a service interval to the TC, but he thought it was a great idea. My second TC had the new vent system and failed after 27k though without ever changing the fluid. Before I take it to the dealer for its 3rd TC, I am going to try the oil change just to see what happens. If I notice good results, I will get the new TC and then change the fluid at least every 10k and hope for the best. May I ask what fluid you are using in there? How long have you been doing the service yourself, every 10k since new?? Thank you!

drdantheman1

My previous 2016 base had the TC replaced around 30k and I never bothered to change the fluid since I traded it in a year later for my current 2016 CS. My CS also had the TC replaced under warranty around 25k miles and I’ve since been doing the TC oil changes myself every 10k miles. It really is very simply, I don’t even use a jack or anything. I can reach the plugs by just crawling under from the side.

fivefathomapple

Since the replacement at 25k, what is your current mileage since doing your own fluid change?

drdantheman1

It has around 39k miles now, I changed the fluid at 31k and am planning on changing it again in a few weeks when it hits 40k.

Quadcammer

For DIY people, I see no reason why not to change the TC oil every time you do an oil change. I'm averaging about 7,500 miles a year, so I'll do my annual oil and tc change at the same time.

deilenberger

I started changing my oil at around 60,000 miles. It's been done 4-5 times now - 103,000 miles. Did it once at another members garage when I was visiting LA (drove from NJ) and it started feeling a bit hinky (that might just have been LA traffic and road surfaces..) Took longer to drink the celebratory beers than to do the change.

I will repeat something I've said before - for everyone enthusiastically heading under their Cayenne..

DO NOT OVERTIGHTEN the drain/fill plugs. YOU WILL CRACK THE COVER if you do. I do not use a torque wrench, since most of them aren't that accurate at low torque values like these plugs have and unless you use one regularly - it's way easy for muscle memory to overcome thinking.. and you over-torque it.. I use a 6" allen wrench, and tighten it with one educated finger. I shoot for snug not tight. It hasn't come out yet so I think that's working.

drdantheman1

Just changed the transfer case fluid tonight for the second time after about 9k miles (just hit 40k miles on odo). Very black. Anyone with a cayenne, highly recommend you take a brave pill and start doing the fluid changes yourself every 10k miles. Agree with what has been said above, I do not use a torque wrench on the bolts, just muscle memory. Snug, but not tight. The fill/drain bolts should NOT sit flush with opening, maybe 1mm hanging out.

driftmotion

Got a new to me 958 S yesterday. First thing I did...

edde

Well nothing lasts forever. This includes my TC fluid change with friction mod. It's not as bad as it was originally but unmistakable.

I'm figuring I got from about 61K to 77K out of it. I may go with ravenol this time around for half the price of the Porsche fluid. I'll leave out the modifier initially and see what happens.

At some point I'd be an idiot to not get out my box of new parts and get this right. Especially since I'm sure my chain in stretched. Just not wanting to be down my daily for any length of time.

Kirill

I'd say order parts from awd.tech (will take some time to get) than either pay shop to do it all. Or pay shop to remove TC and hang on to your car while you run home and rebuild it.

Rebuild process looks very satisfying - click on CC and do translate to English -

realFerdinand

I’m also in NVA, my 2008 Cbase is having transfer case thumping signs. I’m looking a ebay for used case. But don’t know if the parts are interchangeable with other years and engine size.

any input?

edde

It is. I actually bought the parts from Andrew last year but since my fluid treatment worked so great I held off.