1995 C36 with 3.07 rear end- speedo reads off
 

I was hoping you guys might have some suggestions here. My 1995 C36 is a early build Canadian spec car non asr car. I bought the car in the fall last year and have been getting the mechanicals up to speed.

The car has a 3.07 rear end in place of the stock 2.87 rear. I was able to confirm that my speedometer does not read accurately when my wife was following me on the highway the other day.

I am wondering if I am able to swap out the speedometer unit from another w202 cluster (c220 or C280) into my AMG one? The 97 C36 was the only year that came with a 3.07 rear end, but the 97 C36 cluster looks to be a different style than the 95. Would a shop be able to re-calibrate my existing cluster? The likelihood of finding a second hand non asr C36 diff is very slim.

It is very simple to swap out the speedo in a w124 cluster, but do not know where the speed signal comes from on a 1995 w202 cluster.

The signal should come from the ABS computer. But there has been some discussion in the past that the actual speed came from a front wheel making the diff a non issue. There is a chance it is an average from all sensors.

Non ASR cars had the rear speed sensor on the diff pinion not at each rear wheel further compounding the " where is the speed signal coming from? " issue.

The 97 can be version coded so I'd expect the 95 to be as well. I doubt the 97 will interchange with the 95. The speedo isn't a separate unit either as the cluster is full electronic on one circuit board. Does this car read in MPH or KM ? If MPH I'd bet the cluster was changed from KM to federalize the car.

The cluster reads in MPH. I had a friend run the data card that is where I found out it was a early build Canadian spec car. The diff does have the single rear speed sensor at the pinion like you mentioned.

I'd pull the numbers from the dash / use a scan tool to see what dash you have. Far as I can tell, all Canada cars for the past XX years had KM.

I have a 95 C36 as well and although I haven't pulled the cluster to confirm on that car other w202s seem to have a single circuit board and its all controlled electronically. So you can't swap one gauge but I'd imagine you could have some sort of flash done.

I can also say that the speed seems to come from the rear wheels alone. Not an average and certainly not from the front. I've done a few burnouts with mine and the speed goes up at a rate I would expect.