cashenlive Posted September 22, 2022 Share Posted September 22, 2022 I drive a 2015 automatic mack model chu613. Iam currently having an issue when it shifts it comes out of gear then high revs then shifts. By the time it completes that I've lost enough speed that it shifts again therefor does it again. It's worse when I'm loaded. My mechanic is lost we can't figure out what's causing it. Please any help would be greatly appreciated. Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/ Share on other sites More sharing options...
Onyx610 Posted September 22, 2022 Share Posted September 22, 2022 Mdrive? Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510004 Share on other sites More sharing options...
Swishy Posted September 22, 2022 Share Posted September 22, 2022 SORRY eye can't help myself LOL LOL cya 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510005 Share on other sites More sharing options...
Joey Mack Posted September 22, 2022 Share Posted September 22, 2022 you have an M-Drive... I bet the clutch actuator is leaking air, causing the shifting problem.. PTT can do several tests to check stroke and pressure, but I bet you will need to pull the tranny and replace the air bag actuator, may as well replace the clutch as well, because the system is sensitive enough to recognize clutch wear.. Sorry..... Others will chime in... Jojo 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510008 Share on other sites More sharing options...
Onyx610 Posted September 22, 2022 Share Posted September 22, 2022 6 minutes ago, Joey Mack said: you have an M-Drive... I bet the clutch actuator is leaking air, causing the shifting problem.. PTT can do several tests to check stroke and pressure, but I bet you will need to pull the tranny and replace the air bag actuator, may as well replace the clutch as well, because the system is sensitive enough to recognize clutch wear.. Sorry..... Others will chime in... Jojo My thoughts as well Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510010 Share on other sites More sharing options...
Joey Mack Posted September 22, 2022 Share Posted September 22, 2022 Swishy, Here in the States... If you get a C.D.L. (Commercial drivers liscense) in an automatic truck, you are not legally allowed to drive a truck with a manual tranny.. It is something to laugh about.. What a damn waste.... Jojo Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510014 Share on other sites More sharing options...
Onyx610 Posted September 22, 2022 Share Posted September 22, 2022 Also if you take it with a pintle hook then that’s all you get. Want fifth wheel have to take it in that. Also now you have to go to a trucking school and pay a lot of money. Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510018 Share on other sites More sharing options...
Joey Mack Posted September 22, 2022 Share Posted September 22, 2022 Oh Hell, didn't know that... I got my Class 'A' in 1998... What a different world... jojo Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510019 Share on other sites More sharing options...
Onyx610 Posted September 22, 2022 Share Posted September 22, 2022 Yea had mine before all this shit, this stuff all started to evolve about 5 years ago or so. Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510021 Share on other sites More sharing options...
cashenlive Posted September 22, 2022 Author Share Posted September 22, 2022 Clutch is brand new Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510049 Share on other sites More sharing options...
cashenlive Posted September 22, 2022 Author Share Posted September 22, 2022 And yes issue still exists even when I tried it in m-drive 1 Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510050 Share on other sites More sharing options...
fjh Posted September 22, 2022 Share Posted September 22, 2022 Is it throwing up codes ? on the dash! these have synco issues in certain gears 7 th if I remember correctly! does it have 2 speed reverse? Quote Link to comment https://www.bigmacktrucks.com/topic/70463-shifting-issues/#findComment-510079 Share on other sites More sharing options...
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