MR688S Posted July 21, 2020 Share Posted July 21, 2020 Hi All, I bought an '06 MACK MR688S COE Tandem Axle Road Tractor with 8800 hrs. on it to do general short haul runs with a 53' dry van hauling lightweight/high cube material. It has the E7 engine and an Allison 6 speed auto trans., class 8, air brakes, etc... It's a former US Postal Vehicle, so, not sure how good the maint. and daily treatment was and I'm going to go through it and do all maint. and checks. It runs well right now, but I'm a preventative maint. nut because I don't like to breakdown on the road. If any of you can let me know your experiences with the E-7 12 liter engine or direct me to online specs, common issues reports, etc... that would be great! Thanks! Quote Link to comment https://www.bigmacktrucks.com/topic/63410-06-e7-engine-specscommon-issues-newbie/ Share on other sites More sharing options...
Maxidyne Posted July 21, 2020 Share Posted July 21, 2020 That's quite a find- The 2006 Post Office purchase was mostly CX conventionals, but I'd heard rumors there were a few MR cabovers too. Yours is one the best MR tractors ever built, with the modern electronic Allison transmission instead of the crude old valves and fluid controlled transmission. The aerodynamics are awful so it'll get lousy highway mileage, but for maneuvering it tight places it's hard to beat- Even with 53' trailers we could get into some very tight docks with those MRs! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63410-06-e7-engine-specscommon-issues-newbie/#findComment-456344 Share on other sites More sharing options...
MR688S Posted July 22, 2020 Author Share Posted July 22, 2020 There were only two of them in tandem axle and the other was a non-runner. There may be more, but I only needed one. If you have any E-7 engine info beyond specs, I'm interested in finding a service manual, maint. interval chart, etc... I'll get a line card from the local dealer soon. Thanks for the reply! Quote Link to comment https://www.bigmacktrucks.com/topic/63410-06-e7-engine-specscommon-issues-newbie/#findComment-456392 Share on other sites More sharing options...
Maxidyne Posted July 22, 2020 Share Posted July 22, 2020 I'm not sure about the 2006s, but for the earlier USPS fleet purchases Mack put together a custom service manual. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/63410-06-e7-engine-specscommon-issues-newbie/#findComment-456396 Share on other sites More sharing options...
MR688S Posted July 23, 2020 Author Share Posted July 23, 2020 The first thing I want is a Bulldog in the center of the nose or up on the roof. Quote Link to comment https://www.bigmacktrucks.com/topic/63410-06-e7-engine-specscommon-issues-newbie/#findComment-456428 Share on other sites More sharing options...
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