Hi everybody,

Just recently, my tranny has been acting funny. The following are the symptoms:

In the morning, she drives normal. Shifts are just like always, no slipping, no anything. Perfect....

Until she gets to operating temp. Once she does, in park and neutral, there's this little clicking on/off sound, very consistent electronic tick, followed by a tiny mouse like wheeze, then it stops for a few seconds, then it starts again for a few seconds. Once it gets to the point of "ticking", the tranny will slip in/out of gear, etc. The click on/off are spaced evenly apart, almost like a clock. It's a very consistent on/off click followed by the wheeze... so click click wheeze, click click wheeze, click click wheeze...

Fluid levels are fine. Shifts are fine til warm and the clicking starts.

Again, it drives perfectly fine first thing in the morning, or a few hours afterwards. It has to do with temperature, but I don't know what's in there to troubleshoot. Could it be a bad solenoid?

Just trying to get some info before heading to the shop.

 

Do you have the dipstick tool to actually check the fluid level. The XJR has the Mercedes W5a-580 in it and a dipstick tube with a cap and no dipstick. Those transmissions also leaked from the connector sleeve on the right front corner of the trans.

 

Hi,

Yeah... quick question on the dipstick however, does it hit the bottom of the pan when inserted? Or is there a stop that stops it from going all the way to the bottom?

If I use my fabricated tubing... it hits all the way to the bottom and the fluid is right on the mark when hot... measures 2.5 inches of fluid in the tube... maybe a fraction higher... if any. I just put it in til it stops at the pan, plug my side of the tube with my finger, then pull it out to measure the in the tube on the other end.

When using the dipstick, it's hit or miss, and also difficult to see since the fluid has always looked new... so I don't know how reliable I'm reading it.

Anyhow, assuming the level is fine, what electronics are in there that would cause that noise when warm. For example, I could start the car first thing in the morning, let it idle for 15-30 minutes, and it will evenutally do it's ticking sound. On for about 30 seconds, off for about 10 seconds, on again for 30 seconds, etc.

PS.. as long as I don't drive it long enough to get to that clicking sound, the tranny runs perfect. Park to reverse, park to drive, neutral to drive, neutral to reverse, all perfect. Drive from 1st to 5th are perfect as well... up until it's warm enough to do it's clicking thing.

 

From the "for what its Worth Dept."; I bought a spare transmission module from fleabay for about a C note.

 

@sparkenzip... would you happen to know where the ETC Module is located?

 

yeah buddy! I quote, "The system is controlled by a transmission control module,
which is located in the same housing as the engine control module." That puts it in the box on the firewall, under the hood on the right side.

You might want to look at this.

 

Thank you Thank you!!!!!

 

Just installed a replacement transmission in my XJR and purchased a dipstick to perform the fill procedure. I ran out to my garage and measured the level indicator positions for you. At the 25ºC read point, the level ranges from 7/16" - 7/8" from the tip of the dipstick. The 80ºC measurement it is 2 3/16" - 2 5/8".

I was pretty sure I read in the manual that the dipstick does touch the bottom of the pan, but I also read a post entered by Avos, where he believes the dipstick is stopped short of the pan. Not to cloud the issue, but Avos appears to be pretty knowledgeable... on the other hand I am certain the manual says the dipstick hits the pan. I have also read that these Mercedes transmissions are sensitive to the level. If you have your temp at 80ºC, it sounds like your level is in fact OK. If you can, take a temperature reading with an OBDII scanner, or an infrared thermometer to make sure you have the right temperature, that would be added assurance.

Sadly, I do not think the symptoms you are describing sound too good, especially since it appears your oil level is OK.

You could pull the pan off and see what you find lying around in there. I am no expert, so I went to a wrecker and got a replacement unit. I got around to finishing it off last week-end. One thing that is possible though is that a little bit of damage can lead to a lot of damage if you are running metal bits through the system for very long, even though the filter should be stopping it. If it is starting to come apart, the damage can spread.

As a possibility, I was told by a torque converter rebuild shop that the pumps are common fail points on these units. When they go, they often damage the bell housing, so that needs to be replaced or machined. Part of the pump component is integral with the bell housing. He said they cost about $1000.00 to buy. He machines them back to a useful form for $150.00.

The removal and replacement job was not too bad, but I owe Motorcarman and XJRJeff a debt of gratitude for answering my concerns before getting into it.

I am happy to pass on my experience with that, if you end up in the same boat as I did. My transmission went from working and shifting just fine, to not working at all in about the space of 2 or 3 miles!

Good luck with your issue.

 

@JWT... fantastic information. My only shred of hope is that the car drives fine if left off for a while. For example, first thing in the morning, I can drive all over town, stomp on it a stop lights, etc, and it accelerates through the gears is smooth as it always has.

If I let it cool off for a few hours, I can do the same thing... smooth as silk. (I need to add that when it is running well, I can throw it into park and neutral and there is no noise/solenoid clicking at all)... it's only when it gets to operating temperature.

But that darn little moment when some electrical switch/solenoid or whatever it is in there decides to turn on, or off, I don't know... the tranny just decides to act up. It'll slip, clonk into 2nd gear, etc.

I'm hoping it's electrical.. or possibly the hydraulic pump. I have a question about measuring the fluid. What does your dipstick show when the car is off? And does it immediately go down to the 7/8th @ 25ºC when the car is on?.. or does it take a minute or two to go down to that level?

 

when was the gearbox last serviced? it sounds like a faulty temp sensor, or incorrect fluid level. Either way its guessing until the gearbox fault codes are read. Does it show restricted performance? Gearbox fault?

 

Ross , thanks for that PDF file !

 

Here's a link that may be helpful for anybody with this transmission...

722.6

Very detailed... unfortunately can't download without buying... but readable online!

 

Is that the same as this manual ?

ATSG TECH MANUAL & VIDEO 722.6 MERCEDES-BENZ DODGE | eBay


Has someone a source (link) for the video ?

Thanks !

 

technetx - that link is awesome...

 

I will check mine with the engine off when I get home tonoight.
It has been -33º C here the past few days and my garage is set to about 35º F, so mine will not reach the 25º C mark immediately.
Will report back with the engine off & cold dipstick readings, but I assume the level drops as soon as the pump has run for a few seconds from cold. I am now curious as to what the dipstick reads with oil at close to 0ºC which is where mine will be at startup.

Sorry.. I thought you said you were getting a temperature code, but I probably confused your situation with Estillians.

You may be lucky and be able to replace a sensor or solenoid.
Let's hope so

 

Thanks JWT. I'm hoping to narrow it down and see if I can take care of this myself... or at least arming myself with enough diagnostic info that will lead my mechanic down the correct path right from the getgo.

After doing some testing this morning, the click I hear is definitely electronic related. When it clicks on, the idle changes slightly... similar to turning your lights on and off while it's idling.

I'm gonna check the connections and the battery next. I read in a mercedes thread that a few people were having huge problems with their transmissions... gear box faults, slipping out of gear, random shifting, etc... and after a few replacement transmissions and having the same problems after a week or so, they found weak batteries were the problem.

Maybe it's a power problem? Hmmm.

 

Be careful with the Mercedes advice. The battery COULD very well be a problem, as these Jags are known for low voltage issues, BUT while the box is the same, the control module looks to be all Jaguar.

 

As I suspected, The fluid is well past the max line and into the coiled shaft of the dipstick with the transmission cold and engine off. Within 30 seconds of starting the engine, the level drops to almost dry on the dipstick. I would say between 1/8 and 1/4 of fluid. Sorry, I inadvertently left my thermometer at the office, so could not make a 25ºC reading, but with the car at near zero degrees, it took some time before it got into the lowest point of the acceptable 25º range. The engine coolant gauge was about 1/2 way to normal operating temp by then. I was curious to know how long it takes to get to 25º from 0º. At idle, I am guessing almost 10 minutes. I shifted into drive and reverse a couple of times momentarily before a few dips of the stick.

Hope that provides some helpful info. I intend to perform another complete level check at the correct temps before I put a locked cap back on the tube, just to be sure. When taking one reading last weekend, I actually had a hard time getting the temperature up to 80º without driving the car up and down some hills near my house. It then dropped into the low 70's after idling in the garage for about 5 minutes. I thought that was a bit odd. I was suspicious of the accuracy of the temp gun I was using.

The best of luck to you