SL55/63/65/R230 AMG: Help! Oil In SL55 TCU Box / Connectors
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Senior Member
Joined: Jul 2010
Posts: 443
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From: Bay Area
03 SL55
Help! Oil In SL55 TCU Box / Connectors
Hi guys, I took out my TCU to get it tuned. Noticed oil on my hands and saw that there was oil around my TCU connectors/ connector wires. I put the TCU on its side and let the oil drip out. Attached are the pics.
1- What kind of oil is it?
2- Is this normal? Whats the problem? Where should I start looking?
3- What to fix? How much labor / cost?
2003 SL55, TCU is located on the right side panel of the passenger footwell.
1- What kind of oil is it?
2- Is this normal? Whats the problem? Where should I start looking?
3- What to fix? How much labor / cost?
2003 SL55, TCU is located on the right side panel of the passenger footwell.
Former Vendor of MBWorld
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From: Houston
2003 W211 E55, 2003 W220 S600
1- What kind of oil is it? Transmission oil
2- Is this normal? Whats the problem? Where should I start looking? Common problem, wire harness connector on the transmission conductor plate will need to be replaced.
3- What to fix? How much labor / cost? 40 dollar part about 10 mins to replace
open the tcu and clean it with electrical circuit cleaner
2- Is this normal? Whats the problem? Where should I start looking? Common problem, wire harness connector on the transmission conductor plate will need to be replaced.
3- What to fix? How much labor / cost? 40 dollar part about 10 mins to replace
open the tcu and clean it with electrical circuit cleaner
Junior Member
Joined: Feb 2010
Posts: 53
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2004 SL55
The O rings degraded on the control cable plug on the transmission. The pressurized ATF fluid is being force up the inside of the cable jacket into the car. The same transmission type was used in many Mercedes and Chrysler vehicles and all dealers know about it. Google "NAG plug". The plug costs under $20. The O ring material has changed multiple times over the years. I'll bet the new O rings won't last any longer than the old.
It is a messy job and takes way more than 10 minutes. Do it with a cold engine and the car jacked up to keep much of the ATF fluid away from the connector. Even so orange ATF is going to stream out. Be patient and meticulous. Be sure to get the two old O rings out. Be sure to index the new connector properly and don't forcibly twist it. DO NOT over tighten the plug's retainment screw. If you do prepare to spend big bucks.
It is a messy job and takes way more than 10 minutes. Do it with a cold engine and the car jacked up to keep much of the ATF fluid away from the connector. Even so orange ATF is going to stream out. Be patient and meticulous. Be sure to get the two old O rings out. Be sure to index the new connector properly and don't forcibly twist it. DO NOT over tighten the plug's retainment screw. If you do prepare to spend big bucks.
Last edited by busaboy; Sep 11, 2013 at 08:59 PM.
