Digger Dan Posted July 18, 2023 Share Posted July 18, 2023 2000 CL 713 Mack 18 speed transmission, 150,000 miles. Driver is saying it is popping out of gear in low range. Shifter is still in the hole, high range is fine. Some people think it is an air pressure issue, others say something might be bent. Has anyone else dealt with something like this? Any thoughts would be appreciated. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/ Share on other sites More sharing options...
mrsmackpaul Posted July 18, 2023 Share Posted July 18, 2023 If it was a 12 speed I would day there's crud built up in the low range gear were sliding dog goes in I know nothing about 18 speed Mack boxes but feel something similar could be a issue Does this box have a PTO fitted ? Has it had any work done on it ? A few more details here may help people point you in the right direction Paul Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535130 Share on other sites More sharing options...
Digger Dan Posted July 18, 2023 Author Share Posted July 18, 2023 Original owner. Yes it does have a PTO, its a dump truck, I had a clutch replaced 10,000 miles ago. Obviously not an everyday driver, so crud build up could be an issue. Is there typically an access or plan on taking the tranny out? Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535131 Share on other sites More sharing options...
fjh Posted July 18, 2023 Share Posted July 18, 2023 Cl713 likly has a Cummins in it! Check the rear output yoke for tightness! These were quite an issue behind the Cummins ! If it’s tight remove the top rear shift lid and check the shift fork bolt ! If it’s tight then the back section of the trans may have to com off and neew synchro plates installed! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535132 Share on other sites More sharing options...
Digger Dan Posted July 18, 2023 Author Share Posted July 18, 2023 It has the Mack E-7 I believe 460 HP Gold Dog on hood. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535134 Share on other sites More sharing options...
Joey Mack Posted July 18, 2023 Share Posted July 18, 2023 (edited) What gear(s) is popping out? Is it only on the low range side? If you split the gear does it still pop out..? Edited July 18, 2023 by Joey Mack Pour sperring Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535135 Share on other sites More sharing options...
fjh Posted July 18, 2023 Share Posted July 18, 2023 Nice my favourite! Model bar none for a dump truck !stand up oil change!😂It’s best to pull the transmission hatch if the box controls haven’t been mounted over it you might get lucky most box guys don’t consider that someone may have to pull the transmission some day! The trans can stay in the truck to do the back section but likely have to go to the dealer to have it done! Still check the yoke bolt and fork bolt also answer joes question there that is important too for proper diagnostics! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535136 Share on other sites More sharing options...
Digger Dan Posted July 18, 2023 Author Share Posted July 18, 2023 Only low range gears and I believe in high and low on the splitter. (1-10 if I am counting correctly) Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535137 Share on other sites More sharing options...
Joey Mack Posted July 18, 2023 Share Posted July 18, 2023 is the stick jumping out of gear? or is there a grinding then goes in gear? 2 Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535140 Share on other sites More sharing options...
fjh Posted July 18, 2023 Share Posted July 18, 2023 3 hours ago, Digger Dan said: Only low range gears and I believe in high and low on the splitter. (1-10 if I am counting correctly) Plan A just sayin! It’s a pricey project however! Is what it is! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535146 Share on other sites More sharing options...
R.E.D Posted July 21, 2023 Share Posted July 21, 2023 My 10 speed t310m had a similar issue, shift fork was very worn also in conjunction with worn synchro gear ...I took the rear cover off and welded the shift fork up and grinded it down to size..this quick fix got me through the busy summer..then rebuilt the whole transmission..like FJH mentioned,the rear part can be removed but will need a specialty bracket to hold the 3 shafts in place...if truck is new to you ,I would remove transmission completely and have it gone through....main boxes are kinda bulletproof, synchros are the Achilles heels. Just my .02 cents RED 2 Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535362 Share on other sites More sharing options...
Joey Mack Posted July 21, 2023 Share Posted July 21, 2023 been there,, done that,,, R.E.D. is right.. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535366 Share on other sites More sharing options...
fjh Posted July 21, 2023 Share Posted July 21, 2023 2 hours ago, R.E.D said: My 10 speed t310m had a similar issue, shift fork was very worn also in conjunction with worn synchro gear ...I took the rear cover off and welded the shift fork up and grinded it down to size..this quick fix got me through the busy summer..then rebuilt the whole transmission..like FJH mentioned,the rear part can be removed but will need a specialty bracket to hold the 3 shafts in place...if truck is new to you ,I would remove transmission completely and have it gone through....main boxes are kinda bulletproof, synchros are the Achilles heels. Just my .02 cents RED Yup to avoid buying tools pull it stand it up on a wheel rim of the appropriate size or two 6x6 wooden blocks and pop the back cover ! Recommend checking the rear bearings on the main case while you’re there how ever not nessary just a precaution! 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535368 Share on other sites More sharing options...
Joey Mack Posted July 21, 2023 Share Posted July 21, 2023 If you need any specs for your T2013/2018, let us know... I have the correct book on it, and will post pictures for you.. Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535370 Share on other sites More sharing options...
Digger Dan Posted July 22, 2023 Author Share Posted July 22, 2023 Thanks for all the info guys, time to pull it out. Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535403 Share on other sites More sharing options...
mrsmackpaul Posted July 23, 2023 Share Posted July 23, 2023 On 7/22/2023 at 6:18 AM, R.E.D said: I took the rear cover off and welded the shift fork up and grinded it down to size.. Just my .02 cents RED My 12 speed was built up with bronze when I got it and it has done many many 100's of 1000's of miles since and it is still fine I think it was a attempt to stop the range change jumping out of gear Gears were badly worn, I replaced the gears and sliding dog and it has never been a issue since Paul 1 Quote Link to comment https://www.bigmacktrucks.com/topic/73061-mack-18-speed/#findComment-535478 Share on other sites More sharing options...
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