Originally Posted by mkiv808

If we can get the camshaft bolts to a recall, why not this?

Originally Posted by Chadillac2000

A quick update on my Cayenne. Now months after changing the fluid and 1,500 miles later, transfer case is still performing flawlessly in all conditions.

I mentioned in my build thread that earlier this week I went to Georgia to pick up some new wheels. The guy I'd been in contact with had the wheels/tires at his mechanic's shop. When he was helping me load the wheels, I noticed he had what seemed to be a 2011 or 2012 Cayenne Base. I inquired what problems it was having and if it was transfer case related. He explained that the truck was awaiting a transfer case replacement and the owner was deciding whether or not to incur the cost. The car had 70,000 miles and had the "clunk" sound throughout 3rd/4th gear.

I immediately let him on our fluid change secret as a remedy. He was skeptical, but took note of the exact Ravenol fluid that I used. I told him to get my number from the owner of the wheels if he had any questions. English was not his first language, so excuse the grammar, but last night I received this text message:



Add another quick fix to the list!

Originally Posted by Chadillac2000

Copied from my mod/maintenance thread for reference sakes. Thanks to everyone who has contributed to this thread. It was VERY helpful. Please read below.

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Hello everyone! I'm a long time member, automotive enthusiast, and have been maintaining and modifying cars since I was 16 years old (I'm 29 now). Lately I've enjoyed documenting all this in a single thread for reference, so that's what I've decided to do with my latest pickup.

Up until very recently I had two BMW's in the driveway -- a 2008 BMW 135i and a 2008 BMW 535i. The 135i is pampered, overly maintained, and has tons of upgrades. The 535i was a daily driver that I put 197,000 miles on over 7 years. As the magical 200k mileage mark approached, my fiance and I began exploring replacement options and it wasn't long before the car was sold and the search started becoming more serious.





She wanted an SUV. I wanted something that was AWD, European, and that I could tinker with. Without breaking the bank, that ruled out practically everything except the 958 Base Cayenne in the 2011-2012 range. Some quick research unearthed that I needed to look out for transfer case issues (that could possibly be solved with a fluid flush) and that was about it. The proven VR6 engine seemed to perform well, last as long as you were willing to maintain it, and could be reliable for years to come even though the warranty was expired. The V8 in the S was intriguing, but I wouldn't be towing anything, valued gas mileage and longevity over performance in the case of an SUV, and already have a vehicle for use when I want to go fast or tear up some backroads, so with that said I'd rather save the extra coin.

It wasn't long before I'd found a 1-owner, clean-looking car a few hours away in the color combo I wanted: Pure White exterior with Luxor Beige interior. 45,000 miles, nearly-new tires, not a scratch on it, and absolutely packed with options like that I was looking for like heated/ventilated seats, heated steering wheel, rear heated seats, park assist, lane change assist, PCM with Bluetooth/backup camera, and rear power sunshades. I left a deposit on the car sight unseen at an agreed upon price of $33,000 out the door with NC taxes included and began to arrange pickup later that week.

When I arrived to see the car, it was as clean as advertised. It drove well, but after about 10 minutes of driving, the hesitation, vibration, and slipping clutches in the transfer case began acting up. I had been prepared and thanks to some very helpful information on helpful forums by very helpful members, I knew exactly what to look for and where to look for it. When I pulled back in the dealership, I asked the salesman to hop in. As we pulled out onto the main road, I went about half throttle and as soon as we the transmission shifted to 3rd gear, the heavy vibration began, continued through 4th gear and settled down in gears 5-8. There were no other "walnut cracking" sounds while doing figure 8's. Just the hesitation of the clutches in the transfer case slipping. At this point, the car was rather unpleasant to drive in city traffic. Using the Bluetooth system in the car, we called the local Porsche dealership with the salesmen still in the car, and I explained the problem knowing exactly what was causing it. The service technician confirmed my suspicions, and quoted somewhere around $3,000 for a replacement. At that point, I gave the salesman what I'd been setting him up for all along. I offered $30,000 out the door. Chances were they knew the problem was there and were just trying to cover it up, but that's besides the point. I had looked the car up and down, the history checked out, and the owner's manual contained full service history from the Porsche dealership in Georgia where the car was owned for the majority of its life; so I was comfortable purchasing the car -- if they were willing to negotiate. Eventually they caved and I signed papers at $30,000 out the door, so when taxes were taken into account, I gave well under $30,000 for just the car. While the drive home was great on the highway, the slipping transfer case was cause for concern and worried my fiance to no end. Here are some glamour shots of her first night in the driveway.

I couldn't even wait to replace the OEM amber corner lights until I got home. I had already ordered a set of clear corners with chrome coated amber bulbs and had brought them with me. While filling up with gas, I quickly swapped them out using a small screwdriver and a microfiber towel for scratch protection.





















Having done all this research a few weeks prior, I had parts ready to go upon the truck's arrival back home. Service records indicated scheduled oil changes at a Porsche dealership, and most recently an oil change and spark plug change at 36,000 miles. While I was happy to see that the plugs had recently been addressed, the 45,000 current odometer reading meant that the current oil had seen 9,000 miles of use. This is a longer interval than I prefer to run, even with modern day synthetic oils.

The very next morning I had her in my garage with the hood up so I could address a list of things I wanted to get to.



While I use traditional jack stands under my E82 coupe, I invested in a set of RhinoRamps for the 958. This was much easier and provided plenty of clearance for the tasks I was about to take on. Disregard my dumbbell method of keeping the ramps in place while pulling up on them.



Here are some of the goodies I had waiting to address some needed maintenance: a full OEM oil change kit complete with new OEM filter, o-ring, drain plug, 7 quarts of Mobil 1 5W-30 ESP Formula, Ravenol transfer fluid, and Redline 75W90 gear oil.





The first order of business was the transfer case. All evidence online suggested that nearly every failing transfer case was almost fully remedied by a fluid flush, so that's exactly I started with. Using the appropriate sized hex key, I removed the upper fill bolt first, then the lower drain bolt. Talk about easy access -- this fluid change could be done without even raising the car and the bolts are staring you right in the face.

At this point a large stream of dark black fluid flooded out into the drain pan. Within a few seconds all the old fluid was in the pan and out of the case. The fluid was dark, showed signs of a small amount of clutch particle, but did not smell significantly toasted. This left me skeptical that this fluid change was actually going to be the solution to my problem and worry set in.



With the old fluid out, I replaced the drain bolt. These have a built in gasket type material on the threads that seal everything as you tighten. These do not need to be overly torqued! Now it was time to insert the new Ravenol fluid. I've done maintenance on a lot of cars, but this little spout on the Ravenol container coupled with the ease of access to the bolts made this one of the most simple things you can do to a vehicle -- a 10 minutes job and not much to screw up. Squeeze in as much as you can until it starts to come out of the fill bolt. The fluid capacity of the transfer case will leave a small amount still in the Ravenol bottle when it starts overflowing. After tightening down the fill bolt, task one was complete.



Next up was replacing the OEM Mahle filter with a K&N drop-in. Although it was clean, I'm not sure when it had last been replaced, so I wanted to have a fresh interval to go forward with.



Next up was the oil change. All of my prior research on the topic had indicated this would not be fun. Not necessarily difficult as most oil changes aren't, but messy and poor placement of the oil filter in relation to other components. A small socket made quick work of the plastic under-shielding and before long I had full access to the oil drain bolt and oil filter housing. Starting with the drain bolt first, this part was relatively mess-free. I didn't grab a picture of the tool I used this time, but here's what I use for removing all drain bolts these days. I can change the oil on my E82 without getting a drop of oil on my hands,



Next up was getting out the old oil filter removed and letting the oil trapped in the housing drain out. This is where things got extremely messy, even with the appropriate tools.



Once the oil filter housing drain bolt was removed, the oil bath began. I knew what to expect so I was not directly underneath, but the functionality of this design was immediately frustrating. After soaking up all the spills, It was then time to go for the filter cap itself. Once this was fully removed, the real problem became evident. With the old oil filter still installed in the cap, there is no way to bring both pieces down through the opening. The only way I found to get both on my workbench was to remove the filter from the cap while still trapped inside the cage of axle and oil pan. Once the filter is removed, the cap can be turned vertically and brought out. The filter can be pulled down without adjustment at this point.

My hands were so oily at this point, I was not willing to grab my camera. Re-installation was the exact same as removal. After the new o-ring was installed on the cap, the two pieces were lifted into the opening near the oil filter housing separately and coupled together once closer to the mounting point. After clicking the filter into place, screwing the assembly into place was easy.



I then replaced the drain bolt with a new one included in the ECS Tuning oil change kit, sprayed everything down with engine degreaser and left everything as clean as it looked prior to me starting the job. At this point it was time to go back up top and pour in the new 5W30.



Oil cap back on and job complete. I then started the car, verified there were no leaks and replaced the plastic shielding. I'm amazed at how clean this car is from front to rear. The underside looks brand new.



Following that messy oil change, I was done with fluid flushes for the day. I would leave the brake fluid flush with Pentosin Super DOT 4 and the front/rear differential gear changes with Redline 75W90 for another day, perhaps my 60,000 maintenance interval.



I was anxious to see if the Ravenol had saved me a bunch of money, but I had a set of OEM brushed pedals I wanted to throw on before I left. The gas pedal went on easily, but the brake pedal took a little coaxing.





I double checked all my work, verified all the drain/fill bolts weren't leaking any fluids, and backed the 958 off the RhinoRamps. Leaving the garage, there is a quarter of a mile straight stretch with a moderate incline the entire way. The last time I drove the car, about 3 hours earlier, the slipping was significant. On the way hill this time I was immediately disappointed to feel 3rd and 4th gear causing the same hesitation sensation as earlier. As I continued driving for a few miles through numerous stoplights, the hesitation had not gotten worse as it usually would. I chalked this up to placebo effect and wishful thinking.

By the time I'd reached my house about 15 minutes later it seemed the condition had improved even further. I asked my fiance to drive the car and even in the passenger seat, I could stlll feel the slippage as could she. At this point I was coming to terms with the fact I made need to find somewhere to perform a transfer case replacement so we could enjoy our new-to-us car. Despite the fact that I'd negotiated a replacement into the original agreed upon price, I had hopes of solving the problems as others had.

The next morning when I ventured out for coffee and breakfast, I decided to drive the Cayenne despite the transfer case knowing I couldn't really cause any additional damage. To my surprise, I didn't feel any type of slippage for the entire 10 minute drive through various conditions. Coming home, nothing. 3rd and 4th gear were silky smooth. This had happened before on my initial test drive, but it had always showed up eventually.

Over the course of the day I drove the Cayenne for hours in a tons of different situations. NOT ONE SIGN OF TRANSFER CASE SLIP. I was amazed. Letting the new Ravenol fluid flow through the transfer case, get into the clutches, and sit overnight had seemingly solved my issues.

For the next two weeks we drove the Cayenne when we could and could not replicate any of the failures we originally purchased the car with. We were elated and cannot thank the other forum members here who have suggested this particular fluid to remedy the problem. Just to be safe, 500 miles later I drained the fluid again and replaced it once again another fresh bottle of Ravenol. This time it wasn't nearly as dark, but there were still bits of clutch particle. I will most certainly be making this a fluid I change every 15,000 miles. Since I'll be sticking to 7,500 mile oil change intervals, this means once every other oil change.

That is the power of knowledge. Had I not known about this fluid fix, I could have possibly purchased the car for the full agreed upon price, wouldn't have known about the compromised fluid, and would have had the entire transfer case replaced. Instead I purchased the car for $3,000 cheaper than agreed upon, invested $50 in two bottles of fluid, and the issues are fully resolved.

That's all for now, but I have a few more things planned coming up including resetting the oil change interval warning with the POR II iCarSoft handheld device.

Originally Posted by deilenberger

Initial change
Second change within 5,000 mile.
Subsequent changes at every other oil service.

Originally Posted by deilenberger

I think we're up to over 20 people that have reported success by changing the TC oil.. so to me that seems pretty definitive. It's a GOOD THING TO DO.

Just be very careful tightening the two plugs - they only need to be snug.. two people have reported cracking the case around the fill plug so far who overtightened. These are a tapered plug (dumb dumb dumb design IMHO..) and once snug - with the sealant used on them - they won't leak or fall out. If in doubt - order new ones - and get new sealant.

Originally Posted by Chadillac2000

Do we have part numbers for the drain/fill bolts for the TC? I may pick up some new ones for my next change.