Need help with speedo gears...Trying to make T56 Mechanical
08-30-2010, 08:24 AM
#1
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Need help with speedo gears...Trying to make T56 Mechanical I'm trying to convert a T56 Tail housing so I can use my mechanical gauge in my 69 Nova. The drilling/milling and all that jazz are no prbo for me but I need to find the right tooth gears 
I have a Ford 9 inch I'm using with 4.22's and I have a 255/60/15 tire. I need to find a gear to slide onto the output shaft and the one to go on the end of my speedo linkage. Any help would be much appreciated
I have a Ford 9 inch I'm using with 4.22's and I have a 255/60/15 tire. I need to find a gear to slide onto the output shaft and the one to go on the end of my speedo linkage. Any help would be much appreciated
08-30-2010, 10:13 AM
#2
I think you've found that the machined housings use the TH350/T5 style gears. 7/21 won't be enough; you'll be at 7/22; maybe 7/23. Every single online calculator for gears I've found provides different tooth counts than what GM uses (and is accurate!) so I prefer to go by what was used in production.
If you want to do a couple more tailhousings reasonably, let me know. Drop me your addr. if you need the gears; I have them.
If you want to do a couple more tailhousings reasonably, let me know. Drop me your addr. if you need the gears; I have them.
09-01-2010, 10:17 PM
#3
Would it be easier to mount an electric speedometer in the dash? Transfer the needle over and hide the electric speedometer behind the stock face. A lot of V8 RX7's do this.
http://www.norotors.com/index.php/topic,199.0.html
http://www.norotors.com/index.php/topic,199.0.html
