Just when I think I am getting somewhere...

OK a new issue has popped up with the transmission in the XKR over the past couple of days. The first day I got the "gearbox fault" message on the display shortly after starting the car. It went away, then came back and the car felt like it jumped down a gear, and would not upshift.

I pulled over and restarted it and all was fine, for a while. I drove it again about a half hour later, and it felt like it dropped into neutral, the engine was free reving, and the car was coasting down. I tried shifting it through all positions of the J-gate with no luck. Just as I was pulling over to the side of the road, at about 30 MPH, I felt it pop back into gear. I hit the throttle and drove away normally. I did have the battery discharge a couple days before this, so I put it on a charger for several hours, hoping that might help.

But today the coming out of gear until I slow to 30 has repeated a few times. It drove normally all the way to work this morning, but on the way home I got the neutral until I slowed to 30 MPH at least 4 times.

I have also started hearing a noise that sounded like a small dog and squirrel having a fight under the car. It seems to come and go, a couple of times I thought I could make the noise by cornering hard to the right, but not always.

Finally just before I got home, the check engine light came on with the last episode of neutral. The only code I got was P0730 - incorrect gear ratio...

From looking around it seems that a fluid change might be worth a shot? what are the odds of finding the correct fluid anywhere but a Jaguar or Mercedes dealer?

 

Do Not Drive The Car!! You may be destroying something that could be repaired. Continuing to drive the car when the transmission starts to give you symptoms and warnings will assuredly mean a new or rebuilt tranny. Tow it to a trusted shop and have it diagnosed.

 

The thing is I don't have a trusted shop. I tend to do 99% of the work on my cars myself, because it is cheaper, the results are generally better, and I enjoy it. This however may be one of the cases where paying for expertise would be the wise choice.

I have read a few postings where some people are saying they cured a "Bark" or "squeal" by changing the trans fluid and filter. I was just wondering (hoping) a fresh filter, and some fluid may be the fix for me. If these were common symptoms of low or old trans fluid.

It just seems odd that it started all of the sudden, and sometimes works flawlessly...

 

You symptoms are that of low fluid level. Get it checked. there is no dipstick, checking involves oil temp and detailed knowledge of this car. The fluid is special too, not available most anywhere but the dealer.

 

I thought I had read of a common issue of an electrical connector to the trans being the source of a leak. Anyone have information on that?

Mish_Mish seems to be one of the few that I have read information about a fluid and filter change on this generation XKR. He used a filter and gasket from Dodge, and also the fluid specified for a Dodge with this transmission. He sounds happy with the results, however he doesn't have that many miles on it since the change.

 

Valvoline Maxlife meets the specs for the Mercedes tranmission fluid, though it is not Jaguar approved. I run it, as do others, with no adverse effect as far as I can determine.

If it is s more reassurung, get the Mercedes or Dodge fluid...it is still 1/3 the price of the Jag fluid.

The bark and squeal discussions refer to the 6 speed ZF...not our car.

The electrical seal is a common leak point on both the Mercedes and the ZF transmissions.

You need to monitor the temperature during the fill, thought the Mercedes is a bit easier to deal with, since it fills from a dipstick tube, and the oil does not need to be pumped in as with the ZF.

You will need to buy a dipstick, however, avaialble on ebay for a Mercedes 722.6 transmisison.

I would put my money on a leak and low fluid..these transmissions are tough.

 

Well that makes me feel a bit better to hear there are not a lot of known failure issues. I am going to go ahead with the new filter and see how the fluid looks. It makes sense to me to try that out before throwing big $$ at it with a dealer.

I stopped by the local Dodge dealer and they had a filter and gasket in stock, they call the trans the NAG-1. I'm not planning to drive the car until I can work on the fluid and filter change.

I also talked to one of the Dodge techs about their version of the trans a bit. For what it's worth, he said the fluid level is critical and it's better to be under than over full. He said if the level is too high the fluid can foam up, and it will then overheat.

 

I had similar symptoms, however on a smaller scale, that was due to slow leak from the transmission electric plug seal ($8 at dodge dealership).
You must rush to the nearest auto parts store and get ATF +4, it is native to this transmission, however some sticklers insist on purchasing $12/qt mercedes fluid, which smells and looks exactly the same way (I still have one qt left from my E320).
Your transmission is very low on fluid and when you loose gear, like going to neutral, it slipping clutches and you MUST tow it to safety, do not allow it to do that again.
Fighting gerbils are most likely air bubbles in the fluid flow, kinda like low power steering fluid, it can also sound like a boiling teapot.
5WA580 is amazingly durable gearbox and I will not be surprised if yours is not yet killed, but even if it is gone too far, these transmission are easy to find used and most of the time they are good units.
So, let's fill her up and then you will have to drain and fill it few times with cheap ATF +4, before going to permanent fluid like Amsoil, or other $8/qt version, if you must.

Note, I put 3000 miles since I started ATF +4 cycling and now drained and filled first 4 qts of Amsoil, fancy stuff. All symptoms of spontaneous downshifting and staying late in lower gear are gone, so is the rough upshift from first to second, in other words, transmission runs perfect, so much so, that I completely stopped watching and analyzing the shifts.

 

Be aware that if you monitor the gearbox fluid temp using the Datalink Connector and CAN bus, the gearbox needs to be in D or R or you will be reading Engine coolant temp, NOT GEARBOX FLUID TEMP.
See attached TSB.

bob gauff

 

Here is the tip of MB dipstick tool, hope this helps...

 

Any update on this? Hope she lives...

 

Sorry, for no updates. I've been working a ton, luckily that work requires me to be driving company owned vehicles, so the XKR has been parked since I started this thread.

However today I ran out and picked up a couple of quarts of Valvoline Highmileage, and confirmed that NAG1 was listed on the back of the bottle, and using the picture above made some corresponding marks on a stiff 1/8" nylon tube to use as a dipstick.

I made the assumption that if I checked the level quickly after starting the engine that the fluid temp would be close to 25*C since the car has been parked for days. so with that assumption the level on the dipstick was about 3/8" from the tip, and it looked a sickly yellow. I added 3/4 of a quart, restarted the car and checked again, and it was around 5/8" - 3/4."

I took it for a 4 mile ride to lunch and back, and it seemed happy. I have the filter and gasket, if I have time I might try swapping a few quarts of fluid this weekend. I also have a plan to use a thermocouple to monitor fluid temp since i have access to one of those, but not a diagnostic tool.

 

If your transmission pan is wet (meaning electric connector is leaking), dump both quarts in there and do not bother measuring. I am sure you have more than 2 qts missing in there.
Buy entire case of ATF +4, and start playing drain/fill game, about 4 times. Keep checking level every fill.

 

If the connector is leaking I will be fixing that before doing too much else. I assume you need the pan off to do that? I was thinking of doing that when I replace the filter.

I need to get a few things from the Jaguar dealer, so I might as well add that to the list. For giggles I did ask what the going price was on their fluid. $44 per quart and not in stock anyway.

If I have time this weekend, I'll bring it home, get it up in the air, and look at the connector as well as try changing some fluid.

 

Just to get it moving safely, dump both quarts in there, 3/4 will not make a lot of difference, however it might exceed the minimal volume and stop the slippage.

 

I didn't want to take any chances so I bought the Mercedes fluid at $18 per quart. Didn't know about Dodge using the same Mercedes transmission. What car model and years is the NAG-1 in? Same fluid as Mercedes at 1/2 the cost..I like it. BTW..I drained 4 qts and replaced filter. Filled it, drove it and drained and refilled it again. Think it holds about 12 quarts so I hope I replaced enough of the old to last a good while..car had 65k miles at the time, now has 70k.

 

I'm not sure which engines, but the NAG1 trans is in the Charger, 300, and I think the Magnum. I am pretty sure he also said the Sprinter delivery vans use it.

The parts guy at the Dodge dealer asked what kind of car I needed parts for, he looked at me like I was crazy when I told him Jaguar XKR.

After talking a bit, he figured out what I was after. Then he called over one of the trans techs and told him what I was working on. He gave me a bit of information on what he knows about them.

Dodge recommends ATF +4 in their version of the trans.

Here's a look inside; http://www.youtube.com/watch?v=zQwN2-9mLME

Here's a list I found searching Wikipedia;

• 1996–1999 Mercedes-Benz W140
• 2000-2005 Mercedes-Benz W220
• 2006-Present Mercedes-Benz W221 (V12 Models only)
• 1997-2002 Mercedes-Benz W210
• 2002-2004 Mercedes-Benz W211
• 1997-2000 Mercedes-Benz W202
• 2000-2004 Mercedes-Benz W203
• 1998-2005 Mercedes-Benz W163
• 1997-2004 Mercedes-Benz W168
• 2004-Present Mercedes-Benz W169
• 2005-Present Mercedes-Benz B-Class
• 1998-2005 Mercedes-Benz R170
• 1990-2001 Mercedes-Benz R129
• 2001-Present Mercedes-Benz R230 (V12 Model and Earlier, up to 2005)
• 1998-2002 Mercedes-Benz W208
• 2003-2005 Mercedes-Benz W209
• 2000-2006 Mercedes-Benz C215 (V12 Models only)
• 2007-Present Mercedes-Benz C216 (V12 Models only)
• 1996-Present Mercedes-Benz W463 (AMG Models only)
• 2005-2009 Mercedes-Benz SLR
• 2002-Present Maybach 57 and 62
• 2005-2008 Dodge Magnum- All HEMI applications, all AWD applications and some 3.5L RWD V6 applications, year dependent
• 2005-Present Chrysler 300- All HEMI applications, all AWD applications and some 3.5L RWD V6 applications, year dependent
• 2006-Present Dodge Charger- All HEMI applications, all AWD applications and some 3.5L RWD V6 applications, year dependent
• 2008-Present Dodge Challenger- All HEMI applications
• 2006-Present Jeep Commander- 3.7L V6 Applications
• 2005-Present Jeep Grand Cherokee- 3.7L V6 Applications, 3.0L Diesel Applications, SRT8 Applications
• since 2011 Jeep Wrangler (2.8L CRD with automatic transmission only)

I don't think they are all created equal though. Some parts can be interchanged, but don't think you just can put a Wrangler trans in an XKR.

 

Well, I finally got around to working on the XKR tonight. I drained the fluid that I could from the pan, it does not look good. It's very dark, somewhere between well used engine oil and Hershey's chocolate syrup. I put some on a white paper towel and it looks kind of yellowish brownish green, khaki maybe? I'm sure some interior decorator knows the name of whatever color this is.

She just turned 120k miles, and I'll bet its the original fluid. I hope it's not too late.

I was able to drain about 6 quarts of...stuff...out of there through the drain plug. Tomorrow I'll put the new filter and gasket in, take a look at changing the wiring plug, (it's seeping, but not too bad) and top it off with some fresh fluid.

I've finally got the official Mercedes dipstick tool, and borrowed an I/R thermometer gun to check the temp. I read that an I/R reading of the pan is usually with a degree of the temp sensor reading with the scan tool.

 

Well, here's where I am.

I drained another 1/2 quart or so out of the pan after it sat overnight. I dropped the pan, and took off the filter. Neither looked as bad as I expected. No real muck on anything, it all seemed to be suspended in the oil. Not much was stuck to the magnet in the pan either.

I've only been into a few automatics transmissions, and they have all had a lot less miles than this, but a lot more gunk in the pan and on the magnet.

I put on the new filter, and gasket, and put the pan back into place.

The I swapped out the electrical connector housing. It's tight, but I was able to do it without touching the exhaust. I just slide the heat shield backwards out of the way, used a screwdriver the flip the locking tab down to release the connector, then a 7mm to loosen the bolt holding the housing to the trans, and out she came.

I dumped in 4 quarts of fluid, started it up, then added another quart and checked the temp, 26*C and the fluid level was just at the low line. I added another quart for a total of 6 and and cycled the shifter through all of the gears a few times. Then checked it again, this time the temp was up to about 45*C and the fluid was halfway between marks.

So I took it for a drive, and heard that odd noise a couple of times during upshifts, but after a couple of miles that stopped, and it seemed to be shifting just fine. So I came home to check the fluid level again, but the temp of the pan was about 90*C so I am going to let it cool down a bit and try to check it at 85*C.

I did stick the dipstick down there, and the fluid isn't red anymore, back to khaki. Maybe I'll just drain it again, and refill with more fresh stuff.

 

Told ya, you had good chance and it looks like transmission is not dead.
Also, fluid will keep going brown for couple more flush n fills, but after that, cranberry juice baby!