Warpman89 Posted January 15, 2010 Share Posted January 15, 2010 hey guys, i have a mack 12 speed air split and looking underneath it i found that it has two fill plugs; one is 3/4 square on the rear of the tranny, the other is a 1-5/8 bolt plug, both plugs are on the passenger side. my first question is are there separate boxes here that have separate oil levels? next, when i removed the 1-5/8 bolt a little oil came out so i knew it was full, but when i unscrewed the rear, 3/4 plug no oil came out. so, is this just a fill plug or is for measuring the oil level for a separate tranny box? i appreciate the help Quote Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/ Share on other sites More sharing options...
terry Posted January 16, 2010 Share Posted January 16, 2010 far rear one is the fill plug, will flow to the rest of the tranny, the other plug has a catch area there for the magnet in the plug to catch pieces. terry Quote Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-47443 Share on other sites More sharing options...
Warpman89 Posted January 16, 2010 Author Share Posted January 16, 2010 ok, but are the 5 speed main box and the auxiallary spliter separate, or one unit? Quote Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-47445 Share on other sites More sharing options...
terry Posted January 16, 2010 Share Posted January 16, 2010 ok, but are the 5 speed main box and the auxiallary spliter separate, or one unit?That tranny is actually three trannys bolted together and the fluid will run from the back all the way to the front one, has holes from case to case. terry Quote Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-47448 Share on other sites More sharing options...
Warpman89 Posted January 16, 2010 Author Share Posted January 16, 2010 That tranny is actually three trannys bolted together and the fluid will run from the back all the way to the front one, has holes from case to case. terryalright, thanks a lot manso as long as i have oil up to the big plug hole on the front box, im good right? Quote Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-47449 Share on other sites More sharing options...
terry Posted January 16, 2010 Share Posted January 16, 2010 alright, thanks a lot manso as long as i have oil up to the big plug hole on the front box, im good right? You fill the rearmost box and fluid will travel to all three boxes, but you have to fill and let sit for a few minutes to let the oil flow through the boxes. Terry Quote Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-47450 Share on other sites More sharing options...
Lmackattack Posted January 16, 2010 Share Posted January 16, 2010 fill the rear box and wait 10min and check it again. the cold weather will realy slow down oil flow to the other boxes.. All the boxes pass oil to each other via "splash lubracation" Check the magnet plugs and your good to go. Thats a great trans, keep it healthy! Quote Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-47477 Share on other sites More sharing options...
mackniac Posted May 21, 2013 Share Posted May 21, 2013 HI !I can't find anywhere the quantity and type of oil to put into my 12 speed tranny ( from what I read on the 2013 Mack bulletin I see they recommend SAE 50 oil in the manual tranny's ) but I'm not sure a 100% . any one have any info on that please Quote Makniac , collector and customizer of die-cast model in 1/50th scale Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-184587 Share on other sites More sharing options...
MACKS Posted May 21, 2013 Share Posted May 21, 2013 All of the above and one more thing,do not over tighten the fill plug and add a dash of anti seize to it. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-184631 Share on other sites More sharing options...
mackniac Posted May 22, 2013 Share Posted May 22, 2013 ok I'll do that but what about the amount of oil that tranny contains please ? Quote Makniac , collector and customizer of die-cast model in 1/50th scale Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-184727 Share on other sites More sharing options...
MACKS Posted May 22, 2013 Share Posted May 22, 2013 Not sure without looking it up,just grab a 5 gallon bucket and fill er up,get your self one of those pumps that fit a 5 gl pail.. Quote Link to comment https://www.bigmacktrucks.com/topic/12228-mack-12-speed-fluid-level/#findComment-184775 Share on other sites More sharing options...
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