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Transmission problem - strange

2K views 6 replies 4 participants last post by  tbsi430 
#1 ·
G'Day guys
I have a strange thing going on with my CLK 500
Some tranny oil leaking but not huge amounts. dipped and loss seems minimal
Car drives for short distances Ok but then changes gears roughly and then I loose any control over throttle - pedal goes to the floor but the engine doesn't rev. If I stop the car , place in drive it will not rev but moves off at about 1 kph.
If I turn off and restart we can drive off again Ok and the process repeats.
Where do I start?
 
#2 ·
You probably have a leaky seal on the transmission's wiring harness pilot bushing. It's a common problem on these. You need to get it fixed as it can cause several problems - low fluid will make the transmission shift oddly and even harm its internal parts. Also, the oil in the wiring harness can cause shorts that will cause odd behavior. Finally, oil can wick into the wiring and actually make it all the way to the TCU and damage it (it's under the passenger side floor - pull the carpet down to access it). May advice - go ahead and do a fluid/filter change when you get this fixed. It needs it every 60K kms anyhow.
 
#4 ·
Where do I start?
I would start by getting the car up on ramps at the front and removing the 2 splash panels under the car. Then you will see if any ATF has been pooling in the panel under the transmission.

I'm pretty sure that Rudeney is right about your pilot bushing having failed - mine did this quite recently. i let the dealership do the work as it is quit tricky getting the ATF level correct. I didn't have the ATF & filter changed at the time, but it will be done quite soon when the mileage is right.
 
#5 ·
Thanks Keyhole,
Took your advise and got a pro on the job, (not stealership)
When I dipped tranny I did it with engine off - hence the reason that there was minimal oil loss.
It has to be done with engine running!
With engine running different story.
Upon investigation the oil leak is coming from the oil radiator and running down under the car giving impression that is coming from under motor.
Cost to replace and install new radiator. $Au 1200.
We'll check that seal and replace ATF at the same time.
Lack of throttle response is from faulty throttle pedal electronics. $unknown at this stage.
 
#6 ·
When I dipped tranny I did it with engine off - hence the reason that there was minimal oil loss.
It has to be done with engine running!
With engine running different story.
Oh yes. Also it is temperature dependant, so the ATF should be correctly warmed up.

Transmission dipstick has 2 levels shown. Hot @ 80 deg C (176F), Cold @ 25 deg C (77F).

Good to hear that you found where the ATF is leaking from.:)
 
#7 ·
Same thing happened to me except that I was leaking fluid from the pan seal and from a small o-ring on the side of the transmission. My CLK430 wasn't shifting in the mornings or after it had sat for a few hours until would turn the vehicle off and on. In other words until the fluid warmed up enough. The dealer found low fluid and resealed the leak back in Jan 2012. Fast forward today. Two weeks ago my car started doing the same again, thought I had lost fluid again. Wrong! It was the conductor plate with the speed sensors that had gone bad, another $850 repair. Wish the dealer had replaced that at the same time in Jan 2012. After the indie replaced the conductor plate 4 days ago my CLK now shifts better than it has in years and seems quicker as well. So smooth I barely notice the shifts in gear. :)
 
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