C270cdi auto box problems. oil, rebuild or new box?
Discussion
hi, ive recently bought a 2002 c270 cdi and after 3 weeks have started having problems with the auto box. first sign of trouble came when i used the kick down and it suck in secound gear, i stopped turned it off turned it back on again all was ok untill it kick down again and stuck in secound again, this time it wouldnt come out. i took it to work plugged it in to our diagnostics and it came up with p220a fault code.
I then decided to take it to a transmission specialist on my way there it felt like it was slipping in gear. when i picked it up i was told the clutch packs were slipping and was in need of a rebuild. i then got it on my ramp removed the undertray and discovered the gearbox sump was wet. does anyone know if low oil could cause this. if not does anyone know how much the friction and pressure plates are to rebuild the box and what sort of job it is or does anyone have or know were i could get a secound hand box from, any help would be appritiated, thanks.
I then decided to take it to a transmission specialist on my way there it felt like it was slipping in gear. when i picked it up i was told the clutch packs were slipping and was in need of a rebuild. i then got it on my ramp removed the undertray and discovered the gearbox sump was wet. does anyone know if low oil could cause this. if not does anyone know how much the friction and pressure plates are to rebuild the box and what sort of job it is or does anyone have or know were i could get a secound hand box from, any help would be appritiated, thanks.
if the transmission oil pan is damp/wet with transmission oil its probably down to a leaking gearbox electrical plug. The plug where the wiring loom connects to the gearbox. This plug has been modified several times by Mercedes to prevent it from leaking oil. The plug has to o - rings that have been up graded several times as mentioned & im glad to say the latest plug now seems to have sorted the problem.
If the transmission oil level becomes low due to oil loss - yes it will cause slipping problems & possibly cause to transmision to stick in one gear due to lack of oil pressure within the transmission.
One thing worth considering is that if the electrical plug is leaking double check the transmission control module mounted under the floor plate in the passenger front footwell. There is a good chance the oil could have travelled up the wiring loom & into the control module which can give you all kinds of weird symptons - poor gearchanges/sticking in gear etc due to the elctronic circuit boards shorting out. I've seen this quite a bit of recent & it ain't a cheap repair as you'll need a new transmission control module, new wiring loom, gearbox electrical plug & transmission oil plus all the front floor carpets, center console, possibly lower part of dash will all have to be removed to install the new loom.
Another problem with some Mercedes was oil contamination due to a faulty radiator. Transmission oil is cooled via a seperate cooling rad that is all part of the main engine radiator. If its around 2002 model year with a valeo radiator it may be worth visiting your local Mercedes dealer or auto transmission specialist who can carry out a glycol test of the transmission fluid to see if its contaminated with engine coolant. If it is your looking at a new radiator, possible transmission rebuild or at least some sort of transmission oil flush to flush through the old contaminated oil from the cooler lines, transmissin & torque convertor.
I hope you vehicle isn't suffering from these problems but they are worth considering & getting checked. Hopefully it'll just need a new electrical plug fitting to the transmission & then the oil level topping up.
If the transmission oil level becomes low due to oil loss - yes it will cause slipping problems & possibly cause to transmision to stick in one gear due to lack of oil pressure within the transmission.
One thing worth considering is that if the electrical plug is leaking double check the transmission control module mounted under the floor plate in the passenger front footwell. There is a good chance the oil could have travelled up the wiring loom & into the control module which can give you all kinds of weird symptons - poor gearchanges/sticking in gear etc due to the elctronic circuit boards shorting out. I've seen this quite a bit of recent & it ain't a cheap repair as you'll need a new transmission control module, new wiring loom, gearbox electrical plug & transmission oil plus all the front floor carpets, center console, possibly lower part of dash will all have to be removed to install the new loom.
Another problem with some Mercedes was oil contamination due to a faulty radiator. Transmission oil is cooled via a seperate cooling rad that is all part of the main engine radiator. If its around 2002 model year with a valeo radiator it may be worth visiting your local Mercedes dealer or auto transmission specialist who can carry out a glycol test of the transmission fluid to see if its contaminated with engine coolant. If it is your looking at a new radiator, possible transmission rebuild or at least some sort of transmission oil flush to flush through the old contaminated oil from the cooler lines, transmissin & torque convertor.
I hope you vehicle isn't suffering from these problems but they are worth considering & getting checked. Hopefully it'll just need a new electrical plug fitting to the transmission & then the oil level topping up.
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