C32AMG GEARBOX
Author
Discussion

Vesuvius 996

Original Poster:

35,829 posts

294 months

Wednesday 10th September 2008
quotequote all
Mate has a C32 bought recently from MB.

It has a jerky gearbox from 2nd to 3rd (I think) sometimes. Apparently there is some problem with coolant leaking into the box??

Anyone know anything about this? Ta.


krallicious

4,312 posts

228 months

Wednesday 10th September 2008
quotequote all
Is the afformentioned car the same one you took to the Ring the other weekend? hmmmmm wink I'll ask my brother. He generally knows of the most comon Merc faults

iluvmercs

7,541 posts

250 months

Wednesday 10th September 2008
quotequote all
Yup, coolant in the gearbox is a known issue in these.
It's that, or a clutch is going/has gone - then again that wouldn't be intermittent scratchchin

Whatever the problem, it should be covered by the warranty issued with the car (seeing as it's been bought from MB).

Darren

krallicious

4,312 posts

228 months

Wednesday 10th September 2008
quotequote all
iluvmercs said:
Yup, coolant in the gearbox is a known issue in these.
It's that, or a clutch is going/has gone - then again that wouldn't be intermittent scratchchin

Whatever the problem, it should be covered by the warranty issued with the car (seeing as it's been bought from MB).

Darren
Well no need to ask then. Your get it straight from the horse's mouth

timberman

1,393 posts

238 months

Thursday 11th September 2008
quotequote all
has the problem been diagnosed by the dealer or is it just worry/speculation ?

glycol leaking into the gearbox is a known problem with these cars and is caused by the radiator ( usually Valeo ones but has been known to happen with Behr as well ) failing although it's actually pretty rare,

it's commonly diagnosed by taking a sample of fluid from the gearbox and checking for contamination.

harsh gear changes are a symptom of this but many C32's have a harsh change known better as a "transmission jerk" which usually happens around 1500 rpm, this has been well documented and many have tried to cure it but few have succeeded, most of whom just learn to live with it

if it is glycol contamination then it means a new gearbox/torque converter etc = very expensive but obviously this will be covered by the warranty, although I've heard some dealers have tried to get away with just flushing the system and replacing the transmission fluid banghead

HTH


bloodyniceben

299 posts

226 months

Friday 12th September 2008
quotequote all
timberman said:
has the problem been diagnosed by the dealer or is it just worry/speculation ?

glycol leaking into the gearbox is a known problem with these cars and is caused by the radiator ( usually Valeo ones but has been known to happen with Behr as well ) failing although it's actually pretty rare,

it's commonly diagnosed by taking a sample of fluid from the gearbox and checking for contamination.

harsh gear changes are a symptom of this but many C32's have a harsh change known better as a "transmission jerk" which usually happens around 1500 rpm, this has been well documented and many have tried to cure it but few have succeeded, most of whom just learn to live with it

if it is glycol contamination then it means a new gearbox/torque converter etc = very expensive but obviously this will be covered by the warranty, although I've heard some dealers have tried to get away with just flushing the system and replacing the transmission fluid banghead

HTH
I have not heard of Clycol causing gearbox problems in a C Class, its only ever 211 E Classes.

If the problem is Glycol it causes the friction plates in the torque convertor to break up and contaminate the gearbox, but this is virtually always associated with a bad vibration from the car while accelerating.

I would say get the gearbox re adapted at first, the dealer will need to do this, as the Star Diagnosis machine has to be connected.

Ben

P.S I have to do Glycol tests in oil samples all the time for ourselves and other garages, they hardly ever turn up positive.

timberman

1,393 posts

238 months

Friday 12th September 2008
quotequote all
bloodyniceben said:
timberman said:
has the problem been diagnosed by the dealer or is it just worry/speculation ?

glycol leaking into the gearbox is a known problem with these cars and is caused by the radiator ( usually Valeo ones but has been known to happen with Behr as well ) failing although it's actually pretty rare,

it's commonly diagnosed by taking a sample of fluid from the gearbox and checking for contamination.

harsh gear changes are a symptom of this but many C32's have a harsh change known better as a "transmission jerk" which usually happens around 1500 rpm, this has been well documented and many have tried to cure it but few have succeeded, most of whom just learn to live with it

if it is glycol contamination then it means a new gearbox/torque converter etc = very expensive but obviously this will be covered by the warranty, although I've heard some dealers have tried to get away with just flushing the system and replacing the transmission fluid banghead

HTH
I have not heard of Clycol causing gearbox problems in a C Class, its only ever 211 E Classes.

If the problem is Glycol it causes the friction plates in the torque convertor to break up and contaminate the gearbox, but this is virtually always associated with a bad vibration from the car while accelerating.

I would say get the gearbox re adapted at first, the dealer will need to do this, as the Star Diagnosis machine has to be connected.

Ben

P.S I have to do Glycol tests in oil samples all the time for ourselves and other garages, they hardly ever turn up positive.
thanks for the info Ben

I know a lot of C32 owners who have had this fear and a very few have had their transmission replaced (perhaps unnessecerily) because of apparent contamination from glycol, and some have changed their radiators for newer versions as a preventative measure because this seems to be the main fail point.

my radiator actually did fail (Valeo) last year so I had no option but to update it,
still didn't affect my gearbox though

I had the glycol check done on my car some years ago due to a annoyingly harsh gear change (1500 rpm jerk)and it came back negative.

I then tried several times to cure the jerk (transmission fluid change/ updated software etc) but to no avail and I've pretty much given up trying now.
the dealer suggested a new TCU and possibly even a new Torque converter yikes but considering the cost it's not something I'd pay for unless it was a sure thing.

I'm not sure if the dealers ever tried re-adapting the gearbox as a fix

Is this a big job and is it likely to make a difference considering the other things I've had done?

to the OP, sorry for the thread hi-jack


bloodyniceben

299 posts

226 months

Wednesday 24th September 2008
quotequote all
timberman said:
bloodyniceben said:
timberman said:
has the problem been diagnosed by the dealer or is it just worry/speculation ?

glycol leaking into the gearbox is a known problem with these cars and is caused by the radiator ( usually Valeo ones but has been known to happen with Behr as well ) failing although it's actually pretty rare,

it's commonly diagnosed by taking a sample of fluid from the gearbox and checking for contamination.

harsh gear changes are a symptom of this but many C32's have a harsh change known better as a "transmission jerk" which usually happens around 1500 rpm, this has been well documented and many have tried to cure it but few have succeeded, most of whom just learn to live with it

if it is glycol contamination then it means a new gearbox/torque converter etc = very expensive but obviously this will be covered by the warranty, although I've heard some dealers have tried to get away with just flushing the system and replacing the transmission fluid banghead

HTH
I have not heard of Clycol causing gearbox problems in a C Class, its only ever 211 E Classes.

If the problem is Glycol it causes the friction plates in the torque convertor to break up and contaminate the gearbox, but this is virtually always associated with a bad vibration from the car while accelerating.

I would say get the gearbox re adapted at first, the dealer will need to do this, as the Star Diagnosis machine has to be connected.

Ben

P.S I have to do Glycol tests in oil samples all the time for ourselves and other garages, they hardly ever turn up positive.
thanks for the info Ben

I know a lot of C32 owners who have had this fear and a very few have had their transmission replaced (perhaps unnessecerily) because of apparent contamination from glycol, and some have changed their radiators for newer versions as a preventative measure because this seems to be the main fail point.

my radiator actually did fail (Valeo) last year so I had no option but to update it,
still didn't affect my gearbox though

I had the glycol check done on my car some years ago due to a annoyingly harsh gear change (1500 rpm jerk)and it came back negative.

I then tried several times to cure the jerk (transmission fluid change/ updated software etc) but to no avail and I've pretty much given up trying now.
the dealer suggested a new TCU and possibly even a new Torque converter yikes but considering the cost it's not something I'd pay for unless it was a sure thing.

I'm not sure if the dealers ever tried re-adapting the gearbox as a fix

Is this a big job and is it likely to make a difference considering the other things I've had done?

to the OP, sorry for the thread hi-jack
Its not a big job, takes about 45 mins to do properly, as you have to re adapt each gear 4 times on upshifts, then re adapt the downshifts, and its advisable to do the torque convertor lockup clutch while your at it, it needs 2 people, one driving and one contolling the laptop.

Ben