Deere Mack Posted June 2, 2018 Share Posted June 2, 2018 (edited) Hello everyone, I've talked to a few of you before about this problem. I bought a 2017 GU713 MP8 Allison auto dump truck at the end of last year. The problem I had was the PTO rattle being very loud inside the truck. My dealer had made several attempts to quieten it with no luck. I know now this is a known issue but today I hit major discovery. Every bit of the sound I was hearing was traveling up my shift or raise/lower cable. The sound is traveling up the cable like a speaker wire and blasting out of my control console. I remove the cable from the PTO completely, bracket too and no noise what so ever...NONE! So now, how do I fix this? I'd love to hear some ideas. My first thought would be convert to a electronic or air system and eliminate the cable, but I'm not sure whats out there. Edited June 2, 2018 by Deere Mack Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/ Share on other sites More sharing options...
Deere Mack Posted June 2, 2018 Author Share Posted June 2, 2018 I wonder if the air control valves would work. Not sure if sound would travel up an air line the same way. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399847 Share on other sites More sharing options...
RobM626 Posted June 2, 2018 Share Posted June 2, 2018 I don’t know if it would completely eliminate the noise but we changed out the pto on a truck that had a cable system to an air shift pto and the air shift is 100 tines better. Smoother, faster, easier, cable doesn’t freeze up in winter. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399854 Share on other sites More sharing options...
Deere Mack Posted June 2, 2018 Author Share Posted June 2, 2018 4 hours ago, RobM626 said: I don’t know if it would completely eliminate the noise but we changed out the pto on a truck that had a cable system to an air shift pto and the air shift is 100 tines better. Smoother, faster, easier, cable doesn’t freeze up in winter. I feel like it would make a difference but not sure. I wonder if the air lines could act like fiber optic cables and carry the sound or if it's mainly the vibration from the metal cable carrying the noise. Anyone out there have the same set up with air controls? Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399859 Share on other sites More sharing options...
Deere Mack Posted June 2, 2018 Author Share Posted June 2, 2018 Need to talk with a noise and vibration expert. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399860 Share on other sites More sharing options...
RobM626 Posted June 2, 2018 Share Posted June 2, 2018 11 minutes ago, Deere Mack said: I feel like it would make a difference but not sure. I wonder if the air lines could act like fiber optic cables and carry the sound or if it's mainly the vibration from the metal cable carrying the noise. Anyone out there have the same set up with air controls? The air hoses that replaced the cables are hollow plastic 1/4” hoses. The cables obviously have a metal cable with a plastic sheath over them. There’s not really a medium for sound/vibration to travel with the air hoses Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399861 Share on other sites More sharing options...
RobM626 Posted June 2, 2018 Share Posted June 2, 2018 Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399862 Share on other sites More sharing options...
Deere Mack Posted June 2, 2018 Author Share Posted June 2, 2018 I appreciate the information Rob. I've got a good feeling about it all. Been digging in on air control valves and looking at options. If you don't mind me asking, do you remember roughly the cost of converting? Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399863 Share on other sites More sharing options...
RobM626 Posted June 2, 2018 Share Posted June 2, 2018 No problem. I can’t gaurantee if it will get rid of your problem but like I said earlier. There’s a night and day difference between the two as far as ease of operation goes. This set up didn’t once freeze up this past winter and it engages the first time every time. i think the total cost for the pto and air controls costed around 8-900. My in-house mechanic installed it so we didn’t pay labor. I changed out a pto that already had air controls and I paid over 1000 from the mechanic 1 Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399864 Share on other sites More sharing options...
Deere Mack Posted June 3, 2018 Author Share Posted June 3, 2018 (edited) The information below shows how sound travels through different mediums. Make notice to steel vs Nylon or Polyethylene. Most air lines are made of nylon or polyethylene and even between the two of those there's a considerable difference. Looks like the polyethylene line wins my vote. Mild Steel 3235 m/s Nylon 1150 m/s Polyethylene 540 m/s Dry Air (can vary depending on humidity) 346 m/s So the totals are a poly line with air would be 886 m/s vs a steel cable with nylon sheath 4385 m/s. The math says the air control hoist valve vs a cable control should be a lot quieter. 🤔 Edited June 3, 2018 by Deere Mack 1 Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399925 Share on other sites More sharing options...
OldRedMack Posted June 3, 2018 Share Posted June 3, 2018 (edited) Is the cable for engaging the PTO, or running the pump/hoist up and down. I myself hate the air operated hoist, and took it off my truck and replaced with the cable. The air operated hoist doesn't have the same level of control/feathering in my experience. But the air operated pto is the way to go. Edited June 3, 2018 by OldRedMack Didn't finish my thought. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399929 Share on other sites More sharing options...
Deere Mack Posted June 3, 2018 Author Share Posted June 3, 2018 39 minutes ago, OldRedMack said: Is the cable for engaging the PTO, or running the pump/hoist up and down. I myself hate the air operated hoist, and took it off my truck and replaced with the cable. The air operated hoist doesn't have the same level of control/feathering in my experience. But the air operated pto is the way to go. It's the control cable for the hoist up & down. My PTO is air operated. It may be a trade off, feathering capabilities or extremely loud jack hammer sound in cab. Don't forget I understand these trucks are known for the PTO rattle with the Allison auto. But the discovery is that it enters the cab through the Hoist control cable. Remove the cable from the PTO and Bracket, tie it away and no more noise. The only way you'll here it is to roll down your window and hang your head out the cab. If anyone out there has my setup with air operated hoist control please chime in. Thanks! Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399932 Share on other sites More sharing options...
RobM626 Posted June 3, 2018 Share Posted June 3, 2018 The setup I had was cable engage/disengage and cable up/down. I absolutely hated it. Now it’s air everything. And the set up is great. I know what you’re saying about the air not being as precise because the regular truck I drive is like that. I feel like the older the valves get they they get loose and leaky and aren’t as precise. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399937 Share on other sites More sharing options...
Deere Mack Posted June 3, 2018 Author Share Posted June 3, 2018 19 minutes ago, RobM626 said: The setup I had was cable engage/disengage and cable up/down. I absolutely hated it. Now it’s air everything. And the set up is great. I know what you’re saying about the air not being as precise because the regular truck I drive is like that. I feel like the older the valves get they they get loose and leaky and aren’t as precise. I'm sure there's a lot to consider, brand, install etc. But I'd be very interested in hearing from someone with the MP8 and Allison auto with the air control. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399940 Share on other sites More sharing options...
OldRedMack Posted June 4, 2018 Share Posted June 4, 2018 Ok, mine is the t310mlr. So definitely apples to oranges, but I have noticed a new rattle sound in my truck and never thought about the cable. I will have to check that out. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399948 Share on other sites More sharing options...
Mackpro Posted June 4, 2018 Share Posted June 4, 2018 I will pass this info on my my buddy who has 3 GU's with MP8/ Allison. I'm pretty sure he has the cable up/down controls. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399958 Share on other sites More sharing options...
Deere Mack Posted June 4, 2018 Author Share Posted June 4, 2018 4 hours ago, Mackpro said: I will pass this info on my my buddy who has 3 GU's with MP8/ Allison. I'm pretty sure he has the cable up/down controls. If he wants to test it out for himself it will take about 15min to remove the cable completely from the pto & pump, even the line from the bracket so no part of the cable is touching. He'll be amazed, I swear it was like I was in a different truck. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-399965 Share on other sites More sharing options...
Deere Mack Posted June 5, 2018 Author Share Posted June 5, 2018 Looks like I might make the change, got to see if it makes a difference. Anyone that has one as loud as mine will understand and hopefully it'll work and help out some other guy down the road. The air operated hoist control is new to me, I've always had the cable. Is there anything I should know or look for, or is it a just a bad idea for a tri axle dump truck? Any info would be a help. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-400029 Share on other sites More sharing options...
Mackpro Posted June 5, 2018 Share Posted June 5, 2018 My buddy's newest GU is coming in with full air controls for the bed unlike his other GU's . His driver requested it due to thatsvwhat he's used to. We will see how it sounds when it gets here in a few weeks. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-400055 Share on other sites More sharing options...
Hobert62 Posted June 9, 2018 Share Posted June 9, 2018 Could you get a length of rubber gas line and run the cable through? It won't eliminate the direct connection between the control lever and pto but may buffer the sound some. Just a late night idea. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-400272 Share on other sites More sharing options...
Deere Mack Posted June 9, 2018 Author Share Posted June 9, 2018 8 hours ago, Hobert62 said: Could you get a length of rubber gas line and run the cable through? It won't eliminate the direct connection between the control lever and pto but may buffer the sound some. Just a late night idea. Good morning, I appreciate your suggestion. I've tried putting rubber everywhere imaginable. Put rubber o rings in between the pin connection at cable and PTO, thick rubber on and around the cable bracket and in between cable and bracket. I also put extra sound deadening material on the inside of my control tower. I've been desperate to eliminate this problem. lol I think the only way to help with the cable would be to have some type of plastic connection between PTO and cable. Even then sound travels through hard plastic fairly well. Installing air shift next week with polyethylene lines, the quietest way to go. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-400283 Share on other sites More sharing options...
OldRedMack Posted June 10, 2018 Share Posted June 10, 2018 I would compare going to the air control over cable is like going from mechanical to electric controls on a loader. Which would mean that a little bit of movement on the stick goes a long way. Just remind yourself that it is completely different and you will get use to it pretty quickly. Even though I don't like the air controls, if my truck rattled like what you describe then I would swap it out also. Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-400334 Share on other sites More sharing options...
Popular Post Deere Mack Posted July 6, 2018 Author Popular Post Share Posted July 6, 2018 Good morning, hope everyone had an awesome 4th of July. I did remove the cable and put in air for the hoist control and for the record, my truck is a 100 times more quiet than before. None of the sound is traveling directly inside the cab now. The rattle is still there but it's totally different and no where near as noticeable. Anyone who has experienced this probably understands when I say the sound varies, so at times now I cant hear it at all. The air control is different but I'm perfectly fine with it. I've hauled chert and gravel spread with no problems at all. The only noticeable difference for me was mine doesn't automatically jump out of the raise position when the bed is all the way up. I appreciate everyone's input. And for those who told me to get used to it, get a loader radio, thanks for nothing. lol I hope this will help someone out and give them a more peaceful ride like it did for me. 5 Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-402050 Share on other sites More sharing options...
Lema Trucking Posted October 27, 2020 Share Posted October 27, 2020 I am having this problem in my 2021. Its not even 2 months old and im going bat bleep crazy in this cab. any update Deere mack? Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-463112 Share on other sites More sharing options...
Deere Mack Posted October 27, 2020 Author Share Posted October 27, 2020 2 hours ago, Lema Trucking said: I am having this problem in my 2021. Its not even 2 months old and im going bat bleep crazy in this cab. any update Deere mack? Hello, I ended up selling that truck. The air control made a huge difference but the noise was still there. It's like that with most Allison's. Have a friend that just bought a new Pete with the Allison 4700 and it does the same thing. Some are just worse than others and I've seen some that make very little to no noise. Good luck! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/53478-noisy-pto-rattle-with-mp8s-and-allison-auto/#findComment-463116 Share on other sites More sharing options...
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