I seem to recall something about the 4matic system disengaging at about 80mph. I was test driving my "new" car for the first time the other day and noticed the yellow traction control lamp would light up right at 80mph. is this correct?

Also, if I run my car in "test" mode, will it help the transfer case last longer? or will leaving it alone cause it to get stuck?

thanks to everyone for the DIY articles. getting to the blower motor was a breeze thanks to you!

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1967 250SeC
1979 450sel 6.9 (usa)
2009 S550