W209 rebuilt gearbox failure

[aliharry]

Hi all,

I recently purchased a w209 clk500 2006 with the 7 speed gearbox. I bought the car with a transmission fault which caused severe slippage and loss of drive many times. I took it to AGR team aldershot to rebuild the gearbox (I have done a seperate post on the work they did) and they did a good job I felt of rebuilding and getting the car back to me.

fast forward one week later the car was fine until it started to Rev really high on gear changes no matter how I drove, it felt like slippage but was very weird and would then thud into gear.

I’ve taken it down to them again today and they’ve told me the gearbox oil is like milkshake as the coolant has mixed with the oil and they believe my radiator has had it. I wanted to know if this is a common issue or maybe the result of the garage not doing a very good job rebuilding the gearbox? Are there any knowledgable specialists who can shed some light as it feels very weird that they rebuilt my gearbox and now days later the radiator is gone?

Any advice / help with this would be greatly appreciated thank you.

 

[Tonygw]

I have no experience of this, but unfortunately it does sound plausible. I doubt they touched the radiator and its just bad luck that it has happened. I doubt its anything they have done. Hopefully a new rad and fresh fluids should solve the problem.

Others on here may have more experience and say otherwise. Good luck.

 

[noogieman]

Can you see on top of the rad if it says Valeo?
Valeo's are known to be weak!
Behr rad is a much better part.

The C32 AMG had Valeo radiator which was known to leak coolant into transmission and mix with oil, transmission got w@nked
Perhaps you had the same bad luck?

 

[poormansporsche]

2006 is way past the valeo issue rads.

Knowing sod all about these things but is it possible that flushing the old ATF was the straw that broke the camel's back (or in this case the already damaged rad?)

 

[Oleks1992]

Yeah very much likely you'll have a failed radiator if there's coolant in gearbox oil. But do be sure you need to test gearbox oil for glycol to see if it's anti freeze. But it's its failed badly then you might smell it too.

 

[Petrol Pete]

2006 CLK 500 COOLANT IN TRANSMISSION - MBWorld.org Forums

CLK-Class (W209) - 2006 CLK 500 COOLANT IN TRANSMISSION - Help! Supposed MB master mechanic is telling me to change radiator and transmission because of a recent issue with car occasionally going into limp mode. I understand that there was a radiator problem back in 2003 but this is a 2006. He...

mbworld.org

 

[aliharry]

Can you see on top of the rad if it says Valeo?
Valeo's are known to be weak!
Behr rad is a much better part.

The C32 AMG had Valeo radiator which was known to leak coolant into transmission and mix with oil, transmission got w@nked
Perhaps you had the same bad luck?

This issue was well before my car in 2006 years I believe it’s just a common issue on the m113 blocks that can occur

 

[Justintyme]

Its strange allright....reputable company rebuilds transmission ( but makes no mention as to what caused the original failure? ) Then a short time later, problems develop, and the diagnosis is water mixing with the ATF via faulty radiator. Why was this not discovered when the trans was out of the car and stripped down? I'm not expert enough to comment on whats the best course of action at this stage....new Rad ( obviously ) complete change and flush, refill and hope that it will work out? Worth a try in anycase, as you have nothing to lose. But in any case, would be good to get some explanations.