Hey Gang, after 8 years of blissful operation on my 2007 Xfire Convertible the Automatic Transmission is failing at 115,000 miles. Mostly stays in 3rd gear. Sometimes won't go out of 1st. From D to R its like being in Nuetral then goes "clunk". Have several opinions such as T fluid now too low to grab, or he speed sensor plate has gone bad, or some other electronic sensor inside the Transmission has failed... or... all of the above. Any experience you can share would be greatly appreciated. One last note. 2 days before the problem appeared, I installed a new AGM Battery AND a new RCM and it drove like a dream. Wondering if this is an Electrical problem, not a mechanical one. Please HELP!

 

Do you mean fluid level is too low to measure? If so, I think you have answered your own question. Add some fluid to proper level and see what happens. If it starts shifting properly do a flush and filer change and keep your fingers crossed no long term damage has been done.

 

if you replace it go with a V8 5.4- 5 speed 777.6 transmission it fits the crossfire with minimal changes they are stronger and may cost less used.

 

Hmmm ..@N8BENZ...you got one up on me.....I never blew a tranny before......but I did suck down a Bud Light once ........after I realized what I had done.....I find that I am in Limp Mode!

 

Good one!
Now to clean the coffee from the keyboard..

 

Hey Wadsworth, I finally got the XF to my mechanic who said the fluid level was full. No leaks so no loss of fluid. What he did say was the fliud was "burnt". Drained and replaced 9 quarts of oem fliud, new filter and "conditioner" added. The car drives with normal automatic transmission shifts up and down. Was told this "fix" was only temporary and that I should seek out a replacement tyranny. On the flip side, I spoke to my old Mercedes mechanic who I now live 4 hours from, who said... "if it's driving normal after the fluid/filter change, you're probably good for another 100,000 miles! Don't know who to believe and can no longer drive with confidence, not knowing that I won't get stranded somewhere. Where would I even start to look for a new Transmission for a 16 year old car...

 

go back and read post 3-------------------------------- e bay has hundreds your local junk yard also has hundreds

 

It sounds like your transmission problem was simple a lack of proper maintenance. You need to change the transmission fluid at least every 70,000 miles. It really is not much different than the oil in the engine. It will not last for forever. I'm with your Mercedes mechanic: if it ain't broke don't fix it! Run it for 5,000 miles and change that trans fluid again to get out the crap it has acquired from the previous burned fluid. After that keep up on proper maintenance.
When was the last time the coolant was flushed and changed? The differential oil; how about the power steering and brake fluids? Have you looked at the flex discs lately or the central hanging bearing and spline boot on the drive shaft?

 

I realize now how important fluid changes for everything other than just engine oil is. No, I have not done the power steering or the Diff etc., but will! Thanks!

 

Might have problem solved!!

• As mentioned earlier, changed Trans fluids and still had a problem with it staying in 3rd gear. Finally cleared old codes and re-read with an OBD plug in. Code P0715 INPUT SPEED SENSOR came up and described my exact issue. The ECM or TCM detects an irregular signal from the Transmission and puts the car in "Fail-safe" mode to prevent damage. It was suggested that I replace both the input and the output sensors at the same time. The question now is WHERE TO BUY THESE SENSORS. I called Auto Zone and other parts stores. No one has them or knows where to get them. Any non sarcastic suggestions would be appreciated. Thanks!

 

One of the wise Crossfire sages on Facebook says:

Tell him to talk to FCPEuro or Rob at Needswings.
If they can’t help they can point him in the right direction, Rob has dealer connections.

 

Rockauto. com has a speed sensor/conductor plate/filter/gasket set for $126.79. Holstein 2VSS0157 or 2VSS0460.

 

Thanks Wagonerca!!!

 

I don't always buy from that site but so far everything that is suggested has fit perfectly. I use part numbers on their Crossfire and SLK 320 lists to shop around on Amazon and eBay for the best prices.