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RobM626

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

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2 hours ago, Mack Technician said:

sensor (ECU) is the master, engine is the slave, in this case I don't think slave can control masters ability to calculate. Long as sensors are functional, properly set at front timing gap and not tripping a code.....all is well (theoretically).  

The codes that are coming up on computer are those egr and mass air flow codes. I still haven’t had a chance to leave truck at mack to hear what they have to say about possibly reflashing ecu. 

And as far as blink codes go I had a   2-3 (intake air temperature sensor) so I replaced that. And I have a 5-5 (electronic malfunction lamp) that comes on 5 times a day but I don’t know what that even means. I thought the lighting symbol was the electronic malfunction lamp.

i feel like the engine studder is somehow related to the vibration that’s why I thought maybe if the flywheel wasn’t spinning smooth it was throw off the sensor. The weird thing is it only does it when engine warms up. When the engine is cold like the first 15-20 mins it’s running it doesn’t do it. 

I got a lot of “weird things” with this truck as you can tell by now

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You should check your flywheel depth to make sure it has not been surfaced to much, I can't remember the depth it's in a bulletin.  When they surface the flywheel we have seen them come back  and leave a ledge against where the pressure plate bolts in and the clutch will not bolt down flat.  there is a service bulletin about this.  The same machine shop has been turning our flywheel for 30 years but we got one back 2 weeks ago and notice it was not machine all the way out and called them and said they had a new man doing it now.  We sent it back to fix it.  It only about  1/16 ledge but the pressure plate will not bolt down flat.  You should be able to check this in the truck just turn the engine where you can see the pressure plate mounting bolts and make sure it is flat to mating surface.   In the past when we have a vibration in the engine sitting still we remove belt and see if it disappears.  We had one years ago you could look at the pressure plate with the engine at high rpm and see it wobbling,  Have seen where the bearing race have been left out on the main shaft on the mack transmissions inside the input shaft.  Have also seen the bushing missing on input shaft on eaton transmission.

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18 minutes ago, br549 said:

You should check your flywheel depth to make sure it has not been surfaced to much, I can't remember the depth it's in a bulletin.  When they surface the flywheel we have seen them come back  and leave a ledge against where the pressure plate bolts in and the clutch will not bolt down flat.  there is a service bulletin about this.  The same machine shop has been turning our flywheel for 30 years but we got one back 2 weeks ago and notice it was not machine all the way out and called them and said they had a new man doing it now.  We sent it back to fix it.  It only about  1/16 ledge but the pressure plate will not bolt down flat.  You should be able to check this in the truck just turn the engine where you can see the pressure plate mounting bolts and make sure it is flat to mating surface.   In the past when we have a vibration in the engine sitting still we remove belt and see if it disappears.  We had one years ago you could look at the pressure plate with the engine at high rpm and see it wobbling,  Have seen where the bearing race have been left out on the main shaft on the mack transmissions inside the input shaft.  Have also seen the bushing missing on input shaft on eaton transmission.

I’m gonna see if I can find the bulletin. It sounds exactly like it’s wobbling but I can’t visually make out if it’s wobbling or if  that’s just the way the pressure plate looks turning. I’m gonna take a peak under another truck tomorrow and try to compare

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Record the engine going through the RPM ranges that the "stutter/miss" occurs at. Even an ok video recorder would be able to pick up the sound of a miss. The good video consumes about .9MB per second to load so it would have to be short. I did it on page 2 of my AI460 thread, it ate about 7.38MB. Water glass is optional in your case, may not stay put? You can also do a long audio on your smart phone without using much storage. 

 

 

 

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9 hours ago, Mack Technician said:

Record the engine going through the RPM ranges that the "stutter/miss" occurs at. Even an ok video recorder would be able to pick up the sound of a miss. The good video consumes about .9MB per second to load so it would have to be short. I did it on page 2 of my AI460 thread, it ate about 7.38MB. Water glass is optional in your case, may not stay put? You can also do a long audio on your smart phone without using much storage. 

 

 

 

Will do... I actually tried doing that the first week I made a post but the video must have been too long... I’m gonna try to cut down on the size and hopefully It will work... thanks

im gonna try to get truck warm tomorrow and record... if not definitely Monday 

 

i tried viewing your your videos on that thread and they would not view. I’m gonna see how to make them fit... worst case I will message them to you guys... are there size limitations for sending videos?

Edited by RobM626

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4 minutes ago, RobM626 said:

Will do... I actually tried doing that the first week I made a post but the video must have been too long... I’m gonna try to cut down on the size and hopefully It will work... thanks

im gonna try to get truck warm tomorrow and record... if not definitely Monday 

Have your camera software convert it to an "ai" from a "mov"  file as they play easily on computers.

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7 hours ago, Rob said:

Have your camera software convert it to an "ai" from a "mov"  file as they play easily on computers.

Ok gonna download one of the converters thanks

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12 hours ago, RobM626 said:

Will do... I actually tried doing that the first week I made a post but the video must have been too long... I’m gonna try to cut down on the size and hopefully It will work... thanks

im gonna try to get truck warm tomorrow and record... if not definitely Monday 

 

i tried viewing your your videos on that thread and they would not view. I’m gonna see how to make them fit... worst case I will message them to you guys... are there size limitations for sending videos?

There is a max cap on the size of attachment. Someone correct me if it isn’t 8MB, but I think that is what it is?

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I don’t understand why these files won’t play

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I could only see it on my phone......the vid was not very clear for me to see where the issue is as the RPMs were always moving up and down and I cant gather where in the RPM range the vibration was or how bad it surges when you hold the RPM

 

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The descending RPM chop does not seem too bad on the video. Again it may seem worse on the seat.

Engine sounds nice at idle and when it is on it's plateau.

Starts to hunt a bit right at 725RPM, chops 4-5 times and flattens out. Adjust your idle up to 700 (or play around with the number). Maybe it will harmonize better?  

If it has 30,509 hours on it I might grant a pardon?

Would be interesting to see a glass of water on the dash when you get your vibration going.

Edited by Mack Technician

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15 hours ago, Mack Technician said:

The descending RPM chop does not seem too bad on the video. Again it may seem worse on the seat.

Engine sounds nice at idle and when it is on it's plateau.

Starts to hunt a bit right at 725RPM, chops 4-5 times and flattens out. Adjust your idle up to 700 (or play around with the number). Maybe it will harmonize better?  

If it has 30,509 hours on it I might grant a pardon?

Would be interesting to see a glass of water on the dash when you get your vibration going.

The chop starts around 900 when descending. And smoothed out once it returns to idle . The vibration I have is throughout the rpm range I feel it the most around 1000-1100. It’s like a pulse. You can hear/feel it traveling through the transmission too. It’s like Like a wobble . The dash does not shake as bad as it used to since I changed pto, but the mirrors are hard to see clearly out of because of the vibration.

the truck does have 30,509 hours . Without a doubt that truck worked. But like I said before, the way it’s behaving isn’t normal. I know things get old and can’t be New forever. But having to replace the clutch so many times I’m such a short time and basically everything else connected in that area. Something just isn’t right down there. I’m determined to get to the bottom of it.

After you guys asked me those questions if I was sure it wasn’t normal harmonics I got In a few other RD’s that are similar age and not nearly in the condition of mine and they don’t sound and feel like mine does. That truck used to be a pleasure to drive. Now I get out at the end of the day and I need a bottle of Advil from my head pulsating lol

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On 3/20/2018 at 6:28 PM, mrgumby said:

I know this is a little late here but years ago I had a compressor  give me a bad vibration  and that was the last thing I changed found it by accident

I was under the truck today and saw some oil around air tanks I went under and drained tanks and a shit ton of oil came spraying out of the tanks... I’m wondering if maybe my compressor is part of my problem. 

Is oil in the tanks a sure way to know the compressor needs replacing? 

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Whether it is part of your other issue or not, oil in the air system needs to be looked at and repaired.

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1 hour ago, j hancock said:

Whether it is part of your other issue or not, oil in the air system needs to be looked at and repaired.

Ordering compressor and dryer today. 

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3 hours ago, Swishy said:

nuther reason for oil in air tanks:

when the governor on the compressor cuts out @ 120 psi and the air inlet is plumbed up to the engine air intake... if the air cleaner is sum wot dirty n make n the engine suk a little harder this suction can also suk the oil in the compressor up past the piston rings and dump it in the 1st air tank..... good idea to drain air tanks more often..... we have taps on the drains n let m drain O/Night

cya

§wishy 

I change the air filter every oil change which is about every 300-400 hours. It’s usually every 3 months. Every time I change them they’re always pretty clean but I do it anyway.the compressor however is original on the truck so I’m gonna just change it. 

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55 minutes ago, james j neiweem said:

This thread is enough to make your head explode. I feel your pain.:)

I know right . I’m hoping I’m getting somewhere with fixing this thing. I’m still going back and forth with the shop about the clutch flywheel issue. I really feel like they’re trying to cover something up and don’t wanna drop the tranny again .

I just ordered another truck for a different business venture and on the way to New York from Iowa the truck broke down in Pennsylvania. I didn’t even get the truck yet and it’s giving me problems already!!!! I can only imagine the grief that one will cause me!

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1 hour ago, RobM626 said:

I just ordered another truck for a different business venture and on the way to New York from Iowa the truck broke down in Pennsylvania. I didn’t even get the truck yet and it’s giving me problems already!!!! I can only imagine the grief that one will cause me!

What part of Pa?    Instead of fixing it and getting more headaches you could just give it to me.  I'm just looking out for your health.  :D  

  • Haha 1

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2 hours ago, RobM626 said:

I know right . I’m hoping I’m getting somewhere with fixing this thing. I’m still going back and forth with the shop about the clutch flywheel issue. I really feel like they’re trying to cover something up and don’t wanna drop the tranny again .

I just ordered another truck for a different business venture and on the way to New York from Iowa the truck broke down in Pennsylvania. I didn’t even get the truck yet and it’s giving me problems already!!!! I can only imagine the grief that one will cause me!

HA you think you got problems now! Good luck with your new acquisition don't get rid of your old one the vibration issue will be a non issue comparatively speaking! IMO! of coase!

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2 hours ago, Hobert62 said:

What part of Pa?    Instead of fixing it and getting more headaches you could just give it to me.  I'm just looking out for your health.  :D  

Thanks lol you prob would save me from anxiety and high blood pressur

Broke down in Lamar pensylvania at a truck stop. The driver for the delivery company shut the truck down and couldn’t restart it. I think it’s losing it’s prime. I tried to have him do some checks and try a couple things but he couldn’t even find the hand primer. I had the truck towed to Mack out there   I was told it was only 60 miles away. So we’ll see what happens. I really hope it’s nothing major

 

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