On my 89 560SEL occassionally the right hand side bulb that illuminates the rev counter doesn't come on.

Tapping on the front of the cluster a few times causes the bulb to come on.

I am about to pull the cluster and replace both bulbs but is there anything else worth checking whilst I have it apart?

Cheers
Matt.

NO, you are on the right path of what to check

__________________
Jerry

2004 SL500 Black 55K Miles
2002 s500 Black 90K Miles
1986 300E Gold 233K Miles
1966 Twin Cessna 320D
1989 Jeep Cherokee 233K Miles
1994 Ford Van E150 399K Miles

Consider replacing all the bulbs or at least cleaning the bulbs with Windex or alcohol. Pull the gauge cluster dimmer (one screw and some prying) and clean the contacts or fit a new one. Don't forget to clock the dimmer knob when you reinstal the dimmer.

Sixto
95 S420
87 300SDL

One thing that I noticed on the cluster of my 126, is that the white plastic portion that the bulb sits in, had become a bit yellowed over time.
I got out my model paints (I was pleasantly surprised they hadn't dried up after all these years), and using some white paint, touched up the yellowed plastic. Not sure really exactly how much it helped...but, I am sure that it didn't hurt either.

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D