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Can someone show me the shift pattern of a mid-80s Mack 15 speed?  Is it simply a variation on the famous 12 speed?  The shifter looks the same, anyway.  I don't seem to see this transmission very often.  

And how about the (same vintage) 10 speed pattern?  I do see that trans in a lot of trucks with the hi-low button strapped to a straight stick.  No air lines.  

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A old 15 speed should have a high low selector on stick and a deep reduction usually on dash. Deep reduction is your first 5 gears to get you out of a hole then 5 low and 5 high. A 10 speed is five low then shift 5 gears in high. Not sure why shifter looks like a 12 speed it could be a 6 or 7 speed shifter.
 

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This is the truck I saw it in, specifically.  I suppose it could just be a typo.  Looks like a 12 speed shifter to me.  Was there any other Mack trans that used this style of shifter with all the air lines and the switch on the knob? 

http://www.commercialtrucktrader.com/listing/1989-Mack-R688st--120694292

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3 hours ago, sodly said:

This is the truck I saw it in, specifically.  I suppose it could just be a typo.  Looks like a 12 speed shifter to me.  Was there any other Mack trans that used this style of shifter with all the air lines and the switch on the knob? 

http://www.commercialtrucktrader.com/listing/1989-Mack-R688st--120694292

There was a 10 spd that used that shifter, probably a misprint.    terry:D

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The Select Air valve was used on several Mack transmission such as the 12 spd, X107 air 6 spd, T2070B or T2080B.

My RW721 had a ten speed with the selectair shifter. Basically the same as a 12 without the lo-hole. A pleasure to drive.
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