clk 270cdi auto gearbox problem

[alf1956]

Hi there fellow members
I have a 55 plate clk270cdi with 125k on the clock. Today I went on a long run to the coast & back approx. a 200 mile round trip, on the way there we had no problems at all but on the way back I noticed that the revs were high when cruising along & also the cruise control would not work I never gave this a thought till we got back & was dropping somebody off 5 miles from home & when I went to put the car in reverse to turn round it would not go in but then after 30 seconds or so of me moving the gear shift up & down it went into reverse & then on the short journey home I noticed the car wasn't changing up so the revs were on 3,000. When I got home I parked the car on the drive for around 10 minutes or so & took it round the estate & it was changing gear normally. I believe that the autobox is a sealed unit that does not require any topping up but I am wondering if it does need some gearbox oil can anybody advise me please? PS I forget to add that on the way back the cruise control would not work & showed a message along the lines off speedtronic fault visit workshop, I am wondering if this is maybe because the car was not going into top gear & the cruise control only functions when in top gear?

 

[mercedes13156]

Could be a number of things.

Low fluid level in the gearbox.
ATF too hot because there's not enough oil in the box.
Brake light switch failed.
Electronics plate in the gearbox starting to fail.

You need to get the faults diagnosed by a good Mercedes independent garage with STAR diagnostics. if you don't, you just end up guessing and replacing parts to see if it solves the problem. It never does. STAR diagnostics cost about £30 or £40. A litre of ATF could be as little as £15.

 

[LostKiwi]

I believe that the autobox is a sealed unit that does not require any topping up but I am wondering if it does need some gearbox oil can anybody advise me please? PS I forget to add that on the way back the cruise control would not work & showed a message along the lines off speedtronic fault visit workshop, I am wondering if this is maybe because the car was not going into top gear & the cruise control only functions when in top gear?

Whist the gearbox was stated to be filled for life they really aren't. You should have the oil and filter replaced by an independent Merc specialist at around 70k miles or so depending on your gearbox.

Cruise will function in all gears and not just top. You probably need to get it properly diagnosed on a STAR machine to see what comes up.

 

[alf1956]

Thank you all for the helpful advice, can I buy any brand of ATF ?

 

[LostKiwi]

As long as it meets the MB spec. The spec will be listed in the handbook for the car.

 

[John Laidlaw]

Barring that if you cant find it, get in touch with Opie oils and they will provide the right spec at reasonable prices...

 

[charlysays]

If it needs MB236.14/15 then Comma MVATF plus is fine. Not many aftermarket ATFs go higher than 236.15. MVATF is about £6 a litre

 

[alf1956]

Hello, I have just been googling around looking at various things to do with my auto gearbox problem & I came across a you tube video of a clk with transmission problems & it was on tick over & was making a noise similar to a can rattling which my car is doing but I thought it was the heat shield on the exhaust that had become loose but it stops when you rev the engine, can anybody tell me what causes this noise please? I am now fearing the worse!

 

[Steve@Avantgarde]

It wont be low oil level for starters. If it was, the gearbox would be slipping into and out of gear as it looses hydraulic pressure.

Struggling to select gear is either the selector module or the electro plate. I would suggest a visit to a workshop with STAR diagnosis before doing anything else and have the fault codes read.

 

[alf1956]

It wont be low oil level for starters. If it was, the gearbox would be slipping into and out of gear as it looses hydraulic pressure.

Struggling to select gear is either the selector module or the electro plate. I would suggest a visit to a workshop with STAR diagnosis before doing anything else and have the fault codes read.

Thank you, I am going to a friends garage today to get it up on a ramp & check where the rattling is coming from, hopefully it will be a heat shield or something similar.

 

[alf1956]

Update, Had the car up on the ramp at my mates garage & found out that the rattle was the centre exhaust bracket that was broken but still attached to the exhaust & it was rattling about when the revs were put on. The dipstick I ordered has arrived today so I am going to check the ATF level but I am wondering what you do when you have taken off the plastic clip on the top of the dipstick tube? Do you have to break the clip off or does it come off okay so it can be replaced when you take the dipstick out?

 

[John Laidlaw]

Well that's a result!
On my SL the plastic clip was just a push fit and it pushed back on. I assume they are all the same- havent checked any others to be honest...

 

[television]

If the pilot bush had leaked then possible most fluid could have leaked out, this is a common fault.

 

[Steve@Avantgarde]

Just snap the top off and push the tab down through, you will have to get a new tab to replace it.

Like I said earlier, your fault isn't fluid related.