Rig chaser 64 b Mack Posted August 2, 2011 Share Posted August 2, 2011 Hey guys this is my first time posting here I have a 64 b model Mack it has a 1979 maxidyne 300 hp engine out of a fire truck runs great! Freshly rebuilt it had a 5+3 tri plex it blew up just bought a used duplex drove it 60 miles on Sunday and is pouring gear oil out and is way lower geared then the original tri plex ! So I have a Allison 750 brand new that I can get my hands on I need to know if this has been done before??? I need a pto due to crane on my rig. This tranny has it too is this a smart way to go to finish my Mack what do u guys think??? I will post some pics soon and I have a Lund style Fiberglas sun visor brand new for sale Quote Junk Yard Dog 64 Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/ Share on other sites More sharing options...
slpwlker Posted August 2, 2011 Share Posted August 2, 2011 to the jungle Quote Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/#findComment-82932 Share on other sites More sharing options...
Maddog13407 Posted August 3, 2011 Share Posted August 3, 2011 Allison, in a B model?? isnt that Taboo??? Quote Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/#findComment-82982 Share on other sites More sharing options...
Rig chaser 64 b Mack Posted August 3, 2011 Author Share Posted August 3, 2011 half the mack fire trucks are auto , and i cant find a triplex do u know where to look? im in california cant drive my truck till i get this handled Quote Junk Yard Dog 64 Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/#findComment-82983 Share on other sites More sharing options...
David Posted August 3, 2011 Share Posted August 3, 2011 You really don't want a triplex behind a maxidyne 300. That engine produces too much torque. That's probably what happened to your last two transmissions. The Mack 5 sp direct, 6 sp 2 stick, or a T200 series 5, 6, 7 or 8 sp (.6:1 overdrive), 9sp (.71:1) or 10 sp (.78:1) are really what you need. Rear ratio and tire size would help determind what over drive is best. You could also use a roadranger but you will need a Mack belhousing. If you use the auto see if it is a direct or overdrive. You will need to drill a hole on the clutch housing to get to the torque converter bolts. And also install a trans cooler. Quote Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/#findComment-82984 Share on other sites More sharing options...
Rig chaser 64 b Mack Posted August 3, 2011 Author Share Posted August 3, 2011 Thanks for the info I needed a little direction and I got it I thought that was the problem too due to the thermodyne had half the power I need the over drive I also have a higher geared rear end out of a fire truck I will locate a tranny and get my Mack makin money again any one out there know any tranny shops that may have one?? I'm in California thanks !! Quote Junk Yard Dog 64 Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/#findComment-82986 Share on other sites More sharing options...
David Posted August 7, 2011 Share Posted August 7, 2011 Here's one for ya...........http://cgi.ebay.com/ebaymotors/10-speed-transmission-Eaton-ROADRANG-MACK-truck-/150639154776?pt=Vintage_Car_Truck_Parts_Accessories&hash=item2312cb1658 Quote Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/#findComment-83286 Share on other sites More sharing options...
Rob Posted August 7, 2011 Share Posted August 7, 2011 Yup. That is a mid 1980's transmission so parts are easy to get. Would handle your engine easily too. It even appears to have the 1710 series driveline yoke on the rear which is the same most B series trucks used.If you go with a Fuller you will probably need to have the driveshaft lengthened again as you did going from a triplex to a duplex.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/#findComment-83287 Share on other sites More sharing options...
Rig chaser 64 b Mack Posted August 7, 2011 Author Share Posted August 7, 2011 Thanks guys u are a big help I emailed the guy on the tranny from my understanding I need to hook up air to that tranny? If so how does that work? And do I need any additional air system parts? Quote Junk Yard Dog 64 Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/#findComment-83294 Share on other sites More sharing options...
Rob Posted August 7, 2011 Share Posted August 7, 2011 The shift tower and handle appear to be missing in that auction but are pretty easy to get used or new. There is a regulator on the rear of the transmission and you run an air supply line to this regulator. The rest is handled by what is already there although it might be best to replace the slave valve, and filter/regulator assembly while it is on the floor.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment https://www.bigmacktrucks.com/topic/19999-b-model-mack-allison/#findComment-83303 Share on other sites More sharing options...
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