Instrument Cluster Swap
 

Well the gears in my speedo/odo broke for the second time. The VDO repair shop in Greensboro, NC who repaired it the first time (28K miles and 24 months ago) wasn't too sympathetic and didn't offer to warranty his work.

I have a line on a cluster from an '89 560sel.
Will this unit replace the one in my '89 300se exactly? Is there a difference between the gearing of the 560sel and the 300se?
Are the speedo/odos on the 126 chassis prone to early failure? If so, should i stock up on used instrument clusters?

There is probably a difference. I don't know for sure, but I think the number is printed on the back of the odometer.

The speedo is calibrated to the car BY the rear axle ratio. The 300SE & 560SEL rear axle ratio's are a MILE apart so the speed & mileage will be WAY off!

The tach will be expecting an 8 cylinder and you have a six. I know they count ignition pulses to determine RPM. So that will probably not work as well.

M.B. DOC - mo' explanation please
 

I'll be needing to recalibrate a 107 chassis speedo soon as a result of taking it out of a car with a 2.47 rear end and putting it in one with a 3.07 rear end (24% difference).

1. How is recalibration done? Is it accomplished through substitution of different speedo gears, or substitution of different electronic chips, or twisting a screwdriver (adjustment)?

2. Is recalibration something someone with typewriter repair skills and some electronics knowledge could do with a good set of instructions, or only to be tackled by a well-equipped speedo shop?

Most places that do it say it will cost $100, so it can't take that long once you know what to do.

M D "Doc" Nugent
Click here to read about my '72 350SL with engine/trans from a 560SEL

To recalibrate the speedo by that % requires a complete speedo disassembly & replacement of gears in the speedo.

Only VDO repair shops have the correct parts to make that change.