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RobM626

Vibration that 2 mechanics and Mack dealer can’t figure out

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Hello I’m new on this forum but have been reading it for a couple years.

i have a 2000 mack rd dump with an e7-350. Over the past year and a half have been chasing a vibration that no one can get right. Vibration is coming from clutch area and gets really bad around 1100rpm.... I replaced the clutch 3 times . Every clutch was worn prematurely with uneven wear on the facing. I changed the transmission, pto, vibration damper, motor mounts. Also did a camshaft job, 6 injectors and an oil pump. Everytime I put the new clutch in, I leave the shop and it’s great for a couple days then slowly but surely it comes back... I hear the clutch chattering constantly. If I put it in gear and let it coast it feels like a slight grab and slip... while driving if you press and release the throttle you feeling like there’s slack in the driveline... I’m up to 35k $ in repair bills and the truck still isn’t running right... 

Any ideas?

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Hi did anyone think to check the balance of the flywheel? It sounds like you have had many clutches if so. then if the fly wheel has been surfaced lots or even changed  it can change the balance of it just somthin  to think on We once chased an issue in our shop similar to this  on an E6 it turned out to be the flywheel! found it by mounting our input shaft dumbie  in the vice put the fly wheel and pilot bearing on the spigot of the dumbie shaft and the fly wheel would always fall to the same spot like an out of balance tire! ( The wonders of gravity) or frustration of it! :rolleyes:

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That’s exactly what I told the mechanic yesterday... I asked about the flywheel and asked if they checked the run out with a dial indicator. He doesn’t seem to think so but I really do. He mentioned to me that maybe I have some endplay on my crankshaft but what I can’t figure out is why they wouldn’t check that when replacing the harmonic balancer...

if my flywheel is the culprit do I have to replace the clutch again? And is there a way to check if the flywheel is out of balance?

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Like you mentioned use a dumbie input shaft and pilot bearing on a vice?

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Posted (edited)
43 minutes ago, RobM626 said:

Like you mentioned use a dumbie input shaft and pilot bearing on a vice?

Worth a try! fly wheel run out can be checked with fly wheel on the engine! with a dial indicator! balance has to be done by a machine shop or by the dinosaur method I have stated just somthing else to check!   (leave no stone unturned!)

Highly doubt the clutch is hurt!

Edited by fjh

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Did they check flatness and trueness of flywheel housing?

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I highly doubt they did.... I’ve been pulling my hair out with with this truck. Tranny has been dropped 4 times in last year ... everything that I have been telling them goes in one ear and out the other .... 

I just don’t see how 3 clutches could go bad in a year like this... all of them had uneven wear... the clutch that is currently in the truck is 2 weeks old and is starting to feel the same way the previous ones did.

Another flywheel question . Do you think that would cause the engine to stuffer a little when Rpm’s going back down after releasing throttle? Everytime I press and release the throttle and rpm’s for below 800 there’s a slight studder 2-3 times until it returns to idle

 

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If your Mack brand distributor is unable to resolve your truck’s issue, the next step is for their service manager to contact his district service manager (DSM) for assistance. The DSM has near-engineer credentials and is plugged in with Service Engineering.

* All of the DSMs under the former Mack Trucks were some of the most brilliant men I have ever known.

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42 minutes ago, fjh said:

Worth a try! fly wheel run out can be checked with fly wheel on the engine! with a dial indicator! balance has to be done by a machine shop or by the dinosaur method I have stated just somthing else to check!   (leave no stone unturned!)

Highly doubt the clutch is hurt!

Should I tell them to just put a new flywheel on?

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1 minute ago, kscarbel2 said:

If your Mack brand distributor is unable to resolve your truck’s issue, the next step is for their service manager to contact his district service manager (DSM) for assistance. The DSM has near-engineer credentials and is plugged in with Service Engineering.

* All of the DSMs under the former Mack Trucks were some of the most brilliant men I have ever known.

I gave up with the dealer ... Everytime I went there I walked out with a bill that was insane and every symptom I gave them went unlooked... I wish I had some of those brilliant men in my area because my local dealer is terrible

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Posted (edited)
34 minutes ago, RobM626 said:
1 hour ago, fjh said:

Worth a try! fly wheel run out can be checked with fly wheel on the engine! with a dial indicator! balance has to be done by a machine shop or by the dinosaur method I have stated just somthing else to check!   (leave no stone unturned!)

Highly doubt the clutch is hurt!

Should I tell them to just put a new flywheel on?

You need to identify its a problem no point in throwing parts at it ! changing the same part over and over is obviously not working! Like Kevin said get the District service manager involved  (what do you have to loose!):rolleyes:

Note ! The RD is not the nicest thing to pull the trans out of so a higher than average in and  out time would be justified ! 

Edited by fjh

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3 minutes ago, ultratruck said:

I have had problems similar and it would rip the center out of 1 clutch  then go a while and the rip the other one time after time after about 3 or 4 months.  I checked everything to do with the engine, clutch and transmission. After 4 or 5 times I figured it was the angle of the drive line caused from warn suspicion parts.  The drive shaft should  be inspected also. The vibration follows the drive shaft and if you have a fuller Eaton trans sometimes it will brake the pins loose on the synchronizer also.

Yup NO STONE UNTurned! :thumb:

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4 minutes ago, ultratruck said:

I have had problems similar and it would rip the center out of 1 clutch  then go a while and the rip the other one time after time after about 3 or 4 months.  I checked everything to do with the engine, clutch and transmission. After 4 or 5 times I figured it was the angle of the drive line caused from warn suspicion parts.  The drive shaft should  be inspected also. The vibration follows the drive shaft and if you have a fuller Eaton trans sometimes it will brake the pins loose on the synchronizer also.

The driveshaft seems to be ok . And I have the vibration even with the truck not moving in neutral. I changed the yoke on the rear of tranny and a couple of u joints when the tranny was replaced . 

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6 minutes ago, fjh said:

You need to identify its a problem no point in throwing parts at it ! changing the same part over and over is obviously not working! Like Kevin said get the District service manager involved  (what do you have to loose!):rolleyes:

I haven’t been to the dealer since they put the first of the 3 clutches in... another shop put the last clutch. Transmission and pto and injectors... the reason I asked if I should replace the flywheel is BC you said it has to be sent out to check for balance... can you correct an unbalanced flywheel?

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23 minutes ago, Mack Technician said:

Your driveshaft angle is not an inspection. You need a good digital protractor and, if you can find one, a logic calculator..... Online or app. Angle is a great destroyer.

When we start blowing D- mount pumps from suspect vibration our district rep has also pointed finger at engine lateral crank play. In other words how much vertical saddle play in rearmost main bearing.  

I suspect if you could produce angle numbers one of us could calculate it. 

Got ya...sorry for all the questions I’m not a mechanic... but how can you change driveline angles if it’s a spring suspension? Worn springs? Bad torque arms?

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Thanks for the replies guys ... gonna run this stuff by the mechanic... I don’t know how far it will get me ,we’ll see

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Good luck! Remembering after the first premature failure it is the mechanics responsibility to check everything listed in these posts. Not after the third. You have reason to expect satisfaction for the fiasco your going through.

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I'm neither a mechanic or engineer, but I remember a BMW flat twin motorcycle (basically half an air cooled VW engine) that kept eating transmission input shafts way prematurely. After a bunch of expensive repairs someone finally checked to see if the rear flange of the engine that the transmission and clutch mated up to was square with the crankshaft... It wasn't. BMW had mismachined the crankcase halves and a complete replacement was required!

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29 minutes ago, Mack Technician said:

Good luck! Remembering after the first premature failure it is the mechanics responsibility to check everything listed in these posts. Not after the third. You have reason to expect satisfaction for the fiasco your going through.

The truck has been in a shop for a total of 14 weeks the past year and a half.... Everytime they told me what they thought was wrong I said change it without hesitation .ive changed so many parts that weren’t the problem. I just wanted my truck fixed... I’m at the point where I don’t even know if it’s worth keep putting Mo eye in this old truck... the only reason I haven’t bought a new one yet is because this emissions crap is a whole another headache

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Posted (edited)

Got that right. Just had our $850,000 bread and butter money machine sitting in the shop for 3 weeks because the guy who wrote the software program made it so delta sensitive that we cannot clean a DPF filter for reuse. The cleaned filter tripped-up the computer logic. Now have to buy new DPF every time. Liehberr Tech group had no clue why the machine would not run over 4 hours before flipping. It's getting very stupid folks. I feel like they are suffering the industry so when they come out with a poor alternative to diesel we will all jump out of the frying pan into the fire. O.K. done ranting.

Edited by Mack Technician

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3 hours ago, RobM626 said:

The driveshaft seems to be ok . And I have the vibration even with the truck not moving in neutral. I changed the yoke on the rear of tranny and a couple of u joints when the tranny was replaced . 

If the vibration is while parked got to believe I am wrong about the driveshaft being the cause. What king of wear is the clutch showing when taken out, One side, one disc or just inside 1/2 of the paddles?    I had a cat that had a vibration and about 10000 miles later crank snapped at #5 main.  I also had a 237 Mack that vibrated at 1100 - 1400 and never had any issues.  I would dial indicate the crank also at flywheel mount if nothing else shows up.

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2 hours ago, ultratruck said:

If the vibration is while parked got to believe I am wrong about the driveshaft being the cause. What king of wear is the clutch showing when taken out, One side, one disc or just inside 1/2 of the paddles?    I had a cat that had a vibration and about 10000 miles later crank snapped at #5 main.  I also had a 237 Mack that vibrated at 1100 - 1400 and never had any issues.  I would dial indicate the crank also at flywheel mount if nothing else shows up.

Inside half of the paddles I believe... I’m bringing truck in tomorrow and they are going to check the crank endplay and runout.... he assured me the flywheel was in spec but I’m going to make him put the dial on that too. 

Could the flywheel be bad even the there’s no run out?

the mechanic seems to think my thrust bearings could be bad. I’m praying that’s not the case BC I had an inframe done like 3 years ago and I really really don’t want to keep throwing all this money into a 2000 truck

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2 hours ago, Mack Technician said:

Got that right. Just had our $850,000 bread and butter money machine sitting in the shop for 3 weeks because the guy who wrote the software program made it so delta sensitive that we cannot clean a DPF filter for reuse. The cleaned filter tripped-up the computer logic. Now have to buy new DPF every time. Liehberr Tech group had no clue why the machine would not run over 4 hours before flipping. It's getting very stupid folks. I feel like they are suffering the industry so when they come out with a poor alternative to diesel we will all jump out of the frying pan into the fire. O.K. done ranting.

I just brought my 2012 mack to the shop today and they’re saying I need a new dpf, NOx sensor and I’m sure a few more things... the dash looks like a Christmas tree .... calls for 3 regens a day. It’s ridiculous what the industry has come to ... between the choking regulations of the road and the horrible technology on these trucks, it makes it almost impossible for small businesses to survive

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Here we have or did have two clutch rebuilders and they would balance their flywheels after grinding them.To me too many flywheels are turned that dont need to be.I had one that was ground wrong and it would shake the ground it set on.I have seen more than one input shaft twisted or bent also.Also make sure the engine mounts are good and not tighten too much

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