I'm not using stock volvo gauges. I have some Autometer Old Tyme blacks that I am going to use though I perhaps should have gotten the electronic one cause I could enter in the proper information and it would read the correct speed. So I can't help you out on the cable issue. Mine tranny is also a 199 code. Your 155 has a 6 tooth drive gear going to the speedometer gear. You said yours has a white gear in it, thats going to be a 17 tooth gear if it was the cable that came with the transmission, though even if it didn't it should still be a 17. You want to get a 20 tooth gear they are black and are appropriate for the 4.10 rear end and will give you a -1% error instead of the 15% you're getting. The 17 tooth gear was meant for the 3.55 rear end that was in the thunderbirds. I know what I'm going to have to do here I just don't want to. It will recquire me opening up the transmission, pulling the 8 tooth drive gear and replacing it with the 6 tooth so I can also use the 20 tooth speedo gear.
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