Koba111

Hello friends i have problem with 2008 c300 transmision 7g. I changed engine after that in one week it started whistle sound and slipping in every gear after that one guy washed off filter and it fixed it was working pretty well but it still started again i have changed oil like 7000 km ago soo i have to change full transmision or there is a way to fix it

JettaRed

iTrader: (1)

It's a little unclear what you are saying. Did you replace the engine? Transmission? Or did you service the transmission? What do you mean "one guy washed off filter"?

Koba111

I replaced engine and in one week transmision started slipping then i changed transminion oil filter and it was working well but it still started slipping

JettaRed

iTrader: (1)

Got it. I assume you also replaced the transmission fluid when you replaced the filter. Do you know if you have the 7G or 7G+ transmission? What fluid did you use? ATF-134 or ATF-134FE?

If you enter your VIN on www.lastvin.com, look to see if you have Code A89 - REDUCED FRICTION. If so, you should use ATF-134FE (MB236.15 BLUE). If not, you should use ATF-134 (MB236.14 RED) fluid.

TimC300

Pre-2010ish is the regular 7G, ATF 134 red fluid.

Was the trans working fine prior to replacing the engine?

Who changed the trans fluid/filter? How was the fluid filled, was the trans brought up to operating temp then the level checked?

Do you have a Mercedes specific OBD scanner to check any codes?

Koba111

i changed oil and filter in manol service, i havn't checked any code. i already changed transmision soo ill see how new one will work thx for ur attention guys

JettaRed

iTrader: (1)

What fluid did you use? The red and blue CANNOT be mixed or substituted.

Miles Muri

There are two common places for the transmission to leak - 1) at the transmission cooler in the radiator 2) at the tail end of the transmission

If your engine was replaced, the radiator would have been taken out during that process and is probably down a bit on fluid. I had a slow leak on mine and eventually it started slipping until I put in a new radiator and flushed out the trans fluid. I used as my basic guide. Note that transmission temperature is critical and the car must be level (not jacked up just on the front) when setting the fluid level.

The tail end of the transmission can simply be resealed with black RTV.

My guess is fluid level.