Deere Mack

My 17 granite had an similar issue with the Allison.  It was a bad wiring harness from the dash to the trans.  It was pinched and took a while to rub through and short out.

4 minutes ago, fjh said:

Check the little hose at the compressor inlet and under the inlet manifold! those often burst! its a one inch  steel line that runs behind the engine

Good morning and thanks for tip.  I did a visual on that hose and didn't notice anything, but it might take some pressure before that would show up?

when I took it on the last drive, I took my father in law. He's not much of an mechanic but a retired over the road trucker.  He thinks it's an injector.  I'm not sure now because it's worse with an overall loss of power and it seemed to have an rough idle that kind comes and goes.  Pyro is still quick to hit 900 especially in higher gears and I'm sure if I were loaded it would climb back to the 1200 mark.

I have checked for leaks with soapy water but I did not pull the codes or boost. I will this morning.  The noise it's making sounds like a blown exhaust gasket to me, but it's not, no exhaust or intake leaks at all.

took her for a spin after going over a few more things and still have the problem with a lightning bolt on the dash now ⚡ kachow!

40 minutes ago, Mack Technician said:

Sounds like you already solved it. Add another two scoops of determination in finding the leak. You got a pressure tester for CMCAC?

Thanks, good to hear from you! No I don't.  Could this make the "exhaust leak" noise?  What part of the Jake do you think is failing, just sticking, solenoid?

Hello everyone, it's been a while.  I hope everyone's doing well.  My 1996 CH613 E7-427 started out making a noise that sounded like a bad exhaust leak, then in a good pull the pyro would jump up to 1200+/- quickly and running at around 900 but will drop on down at idle.  No noticeable lose in power but I was paying more attention to the noise before I parked it.  Can't seem to find any leaks and was wondering about the engine brake? Anyone have any input? 

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.

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

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.

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.

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!

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.

🤔

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?

Need to talk with a noise and vibration expert.

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?

I wonder if the air control valves would work. Not sure if sound would travel up an air line the same way.

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.

Whats your engine trans set up?

22 hours ago, DailyDiesel said:

Like that old IHC wrecker!  A silver lining to every cloud.  

I knew someone would get a kick out of that.  Talked with the owner, he has plans of an mild restoration.  It sure sounded good..

11 hours ago, Lmackattack said:

 Will it get better. I hope so but likely you are in for a ride.  I would not trust any of these new trucks as far as I could push em. I hope you just found a few simple mistakes and it makes you money...Keep us posted

 

9 hours ago, Dirtymilkman said:

The first month or two is the worst. My buddy bought a new KW and after his fourth trip in with it, the dealer gave him a notebook and said just write all the issues down and we'll deal with it at the next service. But every brand new truck will have breaking in pains. 

Lets hope so!   Loving the automatic, but that PTO rattle is driving me crazy!

Well, after an intense search and coming up with mostly used and abused, I just went for the new truck.  Talked myself into it.  So far it's been in the shop three times:

1. On delivery day, did inspection, power divider wouldn't lock (wasn't even hooked up) and had a bad air leak at tank. Back to shop, fixed.
2. Got an Allison auto and it started acting up, not shifting properly and throwing codes.  Ends up the wiring harness from dash to trans was damaged during the truck build. Back to shop fixed.
3.  Discovered rear drive pinion seal was leaking.  Went to fix and discovered bad threads on pinion gear, replaced with new pinion gear and seal.

Not even 2600 miles.  Someone please tell me it gets better...lol

 

What Mack location are you working with in Alabama? What's the name of your Mack salesman?

Hello, we are in negotiations and I had rather not disclose that information publicly.  Plus I've talked with dealers across the lines.  If there's something you can help me with or need to tell me, feel free to message me. 

Hello, looking at the new tri-axle Granite dump trucks and researching the new transmissions available.  Looking for user experiences.  I've talked with local drivers who said the only thing they didn't like about the earlier auto's (pre 2016?) is down hill backing.  I was told there was no help from the Allison, brakes only.  I've read where the new Mdrive has multiple reverse gears which would help but I can't find anything saying the same for the Allison.  I appreciate everyone's feedback.  thanks!

11 hours ago, MackMann85 said:

it had to be a municipal truck, is that what the salesman told you? If so that very well may add up, however uncommon, and be creating the price premium.  There are plenty of muni trucks that sit several days of the week or are bought with taxpayer money and used as a spare.  I remember the township i grew up in had the dealership do all the maintenance work.  Once every other month they would drop it off on a monday and pick it up the next monday...i bet that old girl had low miles

Yes, said it was a County Truck.