Quick question about W126 transmissions...
 

What is the typical life expectancy of a w126 transmission? A friend of mine has a 1988 300 SEL, and the transmission is making noise at 175k miles, and also he's got a jumpy speedometer. One tech told him he needs a new transmission, I am suggesting checking out the B2 problem first, and suspect the jumpy speedometer has nothing to do with any of this.

Any ideas?

Car has all service records, and was babied by the previous owner.

While many go much further, that trans is at its average lifespan.

The speedo is electric in 126 cars. I'm not sure if a trans related problem could cause such a speedo problem and who knows about a noise. Take it to an experienced tech and have him listen to the noise.

Thanks!