sodly Posted February 23, 2017 Share Posted February 23, 2017 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. Quote Link to comment Share on other sites More sharing options...
alex g Posted February 23, 2017 Share Posted February 23, 2017 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. Quote Link to comment Share on other sites More sharing options...
sodly Posted February 23, 2017 Author Share Posted February 23, 2017 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 Quote Link to comment Share on other sites More sharing options...
terry Posted February 24, 2017 Share Posted February 24, 2017 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 Quote Link to comment Share on other sites More sharing options...
Brian Blaylock Posted February 24, 2017 Share Posted February 24, 2017 Air shift 6 speed? Quote Link to comment Share on other sites More sharing options...
BillyT Posted February 24, 2017 Share Posted February 24, 2017 Yep Brian, the 5 speed maxidyne with a low hole had a rocker button similar to a 13 speed rr! Quote Link to comment Share on other sites More sharing options...
j hancock Posted February 24, 2017 Share Posted February 24, 2017 The Select Air valve was used on several Mack transmission such as the 12 spd, X107 air 6 spd, T2070B or T2080B. Quote JimIt doesn't cost anything to pay attention. Link to comment Share on other sites More sharing options...
Underdog Posted February 24, 2017 Share Posted February 24, 2017 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. Quote Link to comment Share on other sites More sharing options...
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