Jizzo17 Posted 8 hours ago Share Posted 8 hours ago (edited) I was hauling gravel yesterday in my 85 r model and under load 4th gear kept popping out when accelerating. I could apply just a few pounds of pressure to the gear shift lever towards me and it would stay in like normal but if I held it forward it would keep trying to kick out. Is there an adjustment that can be made to the linkage that will fix this or am I going to lose 4th soon? Edited 8 hours ago by Jizzo17 Quote Link to comment https://www.bigmacktrucks.com/topic/75785-mack-5-speed/ Share on other sites More sharing options...
Joey Mack Posted 8 hours ago Share Posted 8 hours ago Well, i dont know of an adjustment. Unfortunately you will need to pull the main floor pan to get the top cover off to inspect the forks, and rails , and look at the clutching teeth on the 4th-5th sliding clutch. Is this a twin stick or do you have a blue range button on the shift knob (T-2070)? Or just a straight 5 spd.? Quote Link to comment https://www.bigmacktrucks.com/topic/75785-mack-5-speed/#findComment-579012 Share on other sites More sharing options...
Jizzo17 Posted 8 hours ago Author Share Posted 8 hours ago (edited) It is just a straight 5 speed. It won’t do it all the time. There is just a range of engine rpm and travel speed that it wants to pop out. Which is very close to the rev match to float into and out of gear. Edited 8 hours ago by Jizzo17 Quote Link to comment https://www.bigmacktrucks.com/topic/75785-mack-5-speed/#findComment-579013 Share on other sites More sharing options...
BOBWhite Posted 4 hours ago Share Posted 4 hours ago I've heard a bad throughout/input shaft bearing can do weird stuff like that too. Pulling the transmission top cover off first like Joey said seems to be the best way forward. -Good luck Quote Link to comment https://www.bigmacktrucks.com/topic/75785-mack-5-speed/#findComment-579033 Share on other sites More sharing options...
mowerman Posted 4 hours ago Share Posted 4 hours ago lets hope thats all it is,,,,,i also believe its possible Quote Link to comment https://www.bigmacktrucks.com/topic/75785-mack-5-speed/#findComment-579039 Share on other sites More sharing options...
mowerman Posted 4 hours ago Share Posted 4 hours ago im thinking just a loose fork,,,i think the forks are held in with a set screw,,good luck Quote Link to comment https://www.bigmacktrucks.com/topic/75785-mack-5-speed/#findComment-579040 Share on other sites More sharing options...
Joey Mack Posted 4 hours ago Share Posted 4 hours ago If it turns out to be the sliding clutch. You dont have to take the whole tranny apart. It can be done through the input shaft hole Quote Link to comment https://www.bigmacktrucks.com/topic/75785-mack-5-speed/#findComment-579050 Share on other sites More sharing options...
mrsmackpaul Posted 2 hours ago Share Posted 2 hours ago Yep, as the others have said, lift the lid and have a look Hopefully it will be something simple Don't use silicone sealant type of deal when putting it back together Just use gasket goo and some gaskets if needed Silicone types of deal ooze out and break off and end up blocking oil galleries and getting caught in the sliding dogs, then the whole box ends up apart to clean the mess up Good luck Paul 1 Quote Link to comment https://www.bigmacktrucks.com/topic/75785-mack-5-speed/#findComment-579053 Share on other sites More sharing options...
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