Lukasswaziek Posted February 3, 2022 Share Posted February 3, 2022 So I have an issue that's been going on as long as I've owned this truck, it's a e6 350 with a maxitorque 9 speed. Between 1200 and 1600 rpm I hear a distinct clatter but only under light load and the truck has to be in gear and rolling. When I rev it up in place at that RPM range It won't make the noise at all, and when I'm pulling a heavy load and get into it, it goes away also. Sounds a little too loud to be an injector knock. Oil pressure is around 30 at idle, 60psi at 1600, 90 at 2100 and oil is clean. Just put a headgaskets in it and cylinder walls look great, all still have crosshatching and no scoring. This noise almost sounds like it's coming from the rear of the engine or more like the bellhousing/clutch. Sounds like it's right under the cab when I'm driving. I'm not sure where to start. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 3, 2022 Share Posted February 3, 2022 I have had the auto power divider send a sound through the drive shaft, imitating a tranny issue. could this be what you hear? (assuming you have an auto power divider)? jojo 1 Quote Link to comment Share on other sites More sharing options...
Lukasswaziek Posted February 3, 2022 Author Share Posted February 3, 2022 I don't think so. I can't feel a driveline vibration and if it was a tranny issue it sounds like it's at the front of the transmission Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted February 3, 2022 Share Posted February 3, 2022 picture looks to show a winch . does this unit have a PTO? Quote Link to comment Share on other sites More sharing options...
Popular Post Joey Mack Posted February 3, 2022 Popular Post Share Posted February 3, 2022 ok. can you sneak a thin bar into the tranny inspection hole and see if you can move the input shaft, side to side.. have someone hold the clutch 1/2 way down, use the bar to see if the input shaft is sloppy.. heck look at the throughout bearing for excessive wear or possibly see a ring spinning on the shaft between the throughout bearing and the clutch brake, if it's still there,, I think you have a spring loaded clutch brake in that old gurl... Jojo 3 Quote Link to comment Share on other sites More sharing options...
Lukasswaziek Posted February 3, 2022 Author Share Posted February 3, 2022 Yes truck has 2 pto's Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted February 4, 2022 Share Posted February 4, 2022 1 minute ago, Lukasswaziek said: Yes truck has 2 pto's if it were the older style spicer clutch they would clatter while you stepped on pedal. no noise parked with 1600 rpms would indicate trans counter shafts aren't moving 100%. under light load ( possibly even bob-tail) has light load on drive train allowing for free style back lash. under HD load the drivetrain is tight under load ; no back lash. far as the PTO question; ! -1 == one of them not engaged ( that was brought up in another text), 2== have you checked back-lash in the PTO's? if they or at least one is a side mount under light load moving the drive gear would be turning. rear mount hyd shouldn't be that noisy. Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted February 4, 2022 Share Posted February 4, 2022 18 minutes ago, Joey Mack said: ok. can you sneak a thin bar into the tranny inspection hole and see if you can move the input shaft, side to side.. have someone hold the clutch 1/2 way down, use the bar to see if the input shaft is sloppy.. heck look at the throughout bearing for excessive wear or possibly see a ring spinning on the shaft between the throughout bearing and the clutch brake, if it's still there,, I think you have a spring loaded clutch brake in that old gurl... Jojo just a thought Joey; if it were the clutch brake or pilot bearing the noise would be there parked and running 1600 rpm's . should'nt make a difference with load weight ?? that's why i thought more toward gears moving or PTO malfunction. ???? 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 4, 2022 Share Posted February 4, 2022 I guess i was thinking a bout a wobbling input shaft when running. and I have seen many broken throughout bearings.. and input bearings rotating like a small football.. however, I can alway's use a little education.. it's tough to diagnose on the phone... so-to speak... jojo 1 Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted February 4, 2022 Share Posted February 4, 2022 agree 110%. see and physically hear make a better diagnostic determination. still good to try and be helpful not to mention keep the ole brain cells active...LOL i'd be interested in the PTO set ups. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 4, 2022 Share Posted February 4, 2022 for sure on the PTO's.. There could be one staying engaged or just f'd up.. for sure.. i would expect a pto noise to increase as you rev up or drive, ... glad to see you on this one 'Mech' jojo 1 Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted February 4, 2022 Share Posted February 4, 2022 also we don't know if when truck is at stand still reving up to 1200-1600. is the driver keeping his foot on clutch pedal or neutral and pedal up ?? "but doctor i don't feel good" -- what hurts---- I don't know but it hurts 😄 1 Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted February 4, 2022 Share Posted February 4, 2022 7 minutes ago, Joey Mack said: for sure on the PTO's.. There could be one staying engaged or just f'd up.. for sure.. i would expect a pto noise to increase as you rev up or drive, ... glad to see you on this one 'Mech' jojo depending on PTO set up , as earlier stated light load less engine noise /more free float gears, heavy load more fuel== more engine noise & less backlash. if it were an engaged pto i would think there would be an over heat smell from hot pto Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted February 4, 2022 Share Posted February 4, 2022 What was the reason for replacing head gaskets and did you have fire ring blowed in one of the gaskets? Quote glenn akers Link to comment Share on other sites More sharing options...
mechohaulic Posted February 4, 2022 Share Posted February 4, 2022 1 hour ago, Lukasswaziek said: I don't think so. I can't feel a driveline vibration and if it was a tranny issue it sounds like it's at the front of the transmission a worn power divider will send a noise through the driveshaft tube into the trans with out causing a vibration. did you try jacking up one side ;;chock blocks and every possible safety feature. put unit in gear slowly bring up the rpms with LIGHT pressure on brake to put resistance on drive line? Quote Link to comment Share on other sites More sharing options...
Lukasswaziek Posted February 4, 2022 Author Share Posted February 4, 2022 (edited) Okay so got the read ends on jackstands, front wheels blocked. Put it in a higher gear and would drag the brakes and now I'm leaning more twords the engine making the noise. It sounds like a real bad injector knock, but for some reason just resonates in the cab. but then again I'm not hugely familiar with Mack trucks and the noises they make. Mostly worked on and drove cats and cummins. I checked the pto's to see if either one was making the noise and it's not that. If you get it at the right rpm it sounds more like a hard knock rather, but otherwise clatters with the engine firing Edited February 4, 2022 by Lukasswaziek Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 4, 2022 Share Posted February 4, 2022 pull the valve covers and look for really sloppy rocker arm's... do you know how to rotate this engine to check each cyl. ? no offense here, just need to know.. jojo 1 Quote Link to comment Share on other sites More sharing options...
Lukasswaziek Posted February 4, 2022 Author Share Posted February 4, 2022 1 hour ago, theakerstwo said: What was the reason for replacing head gaskets and did you have fire ring blowed in one of the gaskets? While it was making that noise and bothering me, I was searching for what It could of been, and there was a small amount of antifreeze leaking from the headgasket that I hadn't noticed before so I suspected that it was a compression leak noise, but it wasn't. No compression passing by the fire rings anywhere. The gasket was weak in a corner though Quote Link to comment Share on other sites More sharing options...
Lukasswaziek Posted February 4, 2022 Author Share Posted February 4, 2022 8 minutes ago, Joey Mack said: pull the valve covers and look for really sloppy rocker arm's... do you know how to rotate this engine to check each cyl. ? no offense here, just need to know.. jojo Yes just adjusted the valves, no difference Quote Link to comment Share on other sites More sharing options...
mechohaulic Posted February 4, 2022 Share Posted February 4, 2022 1 hour ago, Lukasswaziek said: Okay so got the read ends on jackstands, front wheels blocked. Put it in a higher gear and would drag the brakes and now I'm leaning more twords the engine making the noise. It sounds like a real bad injector knock, but for some reason just resonates in the cab. but then again I'm not hugely familiar with Mack trucks and the noises they make. Mostly worked on and drove cats and cummins. I checked the pto's to see if either one was making the noise and it's not that. If you get it at the right rpm it sounds more like a hard knock rather, but otherwise clatters with the engine firing keep in mind these questions might sound simple ; it's a challenge not being there . are you by yourself listening or are you doing the walk around while someone else does the fuel pedal/ brake application? what happens with 1200-1600 rpms and No brake pedal. trying to narrow down possiblities. went from a maybe clutch/ driveline to engine . have been there done that on site frustrations with noise or vibrations. the distant diagnostic has many more options 1 Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 4, 2022 Share Posted February 4, 2022 Mech... you are right... Quote Link to comment Share on other sites More sharing options...
Lukasswaziek Posted February 4, 2022 Author Share Posted February 4, 2022 Mechohaulic I have someone here operating the brake while I listen, and when no brake is being applied you can hear it in the cab but it's quiet, when you push on the brake it gets louder until you pass that RPM range. When I listen next to the engine, I can hear what sounds like the same clatter but not as distinct as when sitting in the cab. Believe me this is frustrating. If I could pinpoint it easier it would not be as frustrating. I've worked on trucks my whole working career, and this one is making me really scratch my head Quote Link to comment Share on other sites More sharing options...
mrsmackpaul Posted February 4, 2022 Share Posted February 4, 2022 Well have just read thru this and this is what I understand from what I have read Noise is believed to be coming from the back of the engine or front of the transmission Only happens in gear with a light load If it was mine I think it would be time pull the transmission back if its a concern But I would check the endplay on the crank first to make sure it isn't floating to much and allowing something to just touch somewhere It has gotta be something pretty simple going on The transmission shafts have a fair bit of float forwards and back as I feel the crank Joey will probably have the specs at hand for the crank float and the transmission, well it will be what it will be, they are a pretty agricultural transmission but tough as nails Paul Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted February 4, 2022 Share Posted February 4, 2022 I will look for the crank end play spec. I think its .004"-.012"... jojo Quote Link to comment Share on other sites More sharing options...
Popular Post mechohaulic Posted February 4, 2022 Popular Post Share Posted February 4, 2022 18 hours ago, Lukasswaziek said: Mechohaulic I have someone here operating the brake while I listen, and when no brake is being applied you can hear it in the cab but it's quiet, when you push on the brake it gets louder until you pass that RPM range. When I listen next to the engine, I can hear what sounds like the same clatter but not as distinct as when sitting in the cab. Believe me this is frustrating. If I could pinpoint it easier it would not be as frustrating. I've worked on trucks my whole working career, and this one is making me really scratch my head i'll bet you didn't try the "heater hose technic" you and others will have a good laugh . take a length of heater hose ; 1 in x 2-3 ft long worked for me. i know today they make fancy stethoscopes . hose to your best ear and follow under neath till you close in on the noise. that noise isn't bad, frustrating and making me scratch my head is ::why did i say I DO twice!!!LOL 3 Quote Link to comment Share on other sites More sharing options...
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