Vibration

[Hoefler]

Has any one experienced a vibration in the RPM range of 2200 to 2800???



Here is what I am experiencing: No matter the gear, except 6th, I get a reoccurring vibration from 2200 - 2800 RPM. It is like running over fine rumble strips. It will come and go very frequently. I can set the cruise, lets say 4th gear, with the RPM at 2700, about 65 mph. Drive a little ways and it will start and will fade in and out. OK, without changing anything except shifting to 5th, the RPM will drop and the vibration disappears. I can repeat this in 2nd, 3rd, 4th, and 5th. It may do it in 6th, but I have not driven it fast enough to get the RPM in the range long enough. I am at 47000 miles, it has been doing it for the last 30000 or so miles. It started when I had my 16 enclosed trailer on and in a pull on a hill. I could never get it to do it for the dealer to experience except once. They swapped out the converter and I could not get it to do it on flat ground. It is very pronounced when pulling the 5th wheel on a grade. Out of shear luck or stupidity, I figured out how to get it to do it with regularity, while in traffic I was running in 5th and accelerated to 75 mph, ( I was running my dad to the hospital) and there it was. The next day I played with it and figured it out, it was RPM related. Anyways, it is at the dealer now, they have installed a new transfer case, torque converter, and pump/valve assembly in the transmission. They have pulled the covers on the axles and found nothing. They are thinking of replacing both axles and the drive shafts. I used to be a transmission/drive line tech for a Kenworth shop in Kansas, I think they are going the wrong way. I believe it is RPM related not road speed related, therefor, I think it is in the transmission, engine or anywhere in between. I was wondering if anyone in TDR land has experienced this or maybe some idea.



Thanks.



P. S. So far, all is being taken care of under warranty.

 

[Hoefler]

As of 11:30 today, the dealer has ordered a front axle, in the process of checking the compression, leak down test, and crankshaft end play. Still no answer

 

[mikeshauling]

Ive heard a few guys with a shudder at certain RPMs and it was TC related.

 

[sag2]

Your dealer needs to stop guessing and get a vibration analyzer on the truck ASAP. The way he is going he is just throwing good money and parts away, and probably has no chance of repairing it, except by accident that is.

 

[Hoefler]

Your dealer needs to stop guessing and get a vibration analyzer on the truck ASAP. The way he is going he is just throwing good money and parts away, and probably has no chance of repairing it, except by accident that is.

How does a vibration analyzer work and where do you get one??

 

[MullenaxM]

How does a vibration analyzer work and where do you get one??

Have the Dealer call there Chrysler Tech Advisor, He/She should have one.



Mike

 

[Hoefler]

New transmission arrived late Thursday, they will install Monday. We will see.

 

[sag2]

Well so far, your dealer has guessed wrong with about $5,000 of the factory's money, and I'm betting that the next $5,000 they spend on the trans is a complete waste as well. I'm going out on a limb here and guessing your dealer is an idiot. As Mike said, have them call their TA and borrow his/her MTS 4100 and get to the root cause in about five minutes instead of in increments of $5k. Any GM dealer will have one they can borrow as well.

Reading this kind of ineptness drives me crazy. Hopefully when the returned parts hit the quality return center the dealer will get charged back for the repairs. Then he will realize education is far cheaper than not having it.

 

[Hoefler]

Ironically, they are removing the new parts as they find out that it did not fix it. I questioned them on the vibration analyzer, the told me that it did not help them at all on this situation.

 

[sag2]

Your dealer does not actually have one, or if he does, he does not understand how to use it. If he has the old style EVA he has to do a little math, unless he has some software called "DAVE" that is just an Excel spreadsheet that converts the frequency of the observed vibration into the source, ie engine, first order drive line, second order drive line etc.
If he actually has an MTS 4100 it reads the vibration and does the math internally and displays the vibration source on the screen.
I have spent many hours using both tools on lots of trucks, and although sometimes it's harder to actually fix it once identified, the tool ALWAYS correctly identifies the source of the vibration.
Look at the G's column on the screen. You can see the first order (balance) drive line vibration is what we are looking for because it is the highest hitting vibration in the number of G's. It is the strongest vibration the tool is picking up out of all the vibrations the car is making. The same would hold true with your truck, it will have several vibration frequencies showing up, but the annoying one will be the one with the highest G's, and it also should come and go as it cycles in and out as you describe in your first post.

 

[Hoefler]

They told me they had an older one, but not like the one the tech rep hauls around with them.

 

[MMeier]

Sorta on topic... do you think regular driveline shops would have one of these ? Trying to figure out where my vibration is coming from at about 70-80 MPH.

 

[Hoefler]

Sorta on topic... do you think regular driveline shops would have one of these ? Trying to figure out where my vibration is coming from at about 70-80 MPH.

If you can down shift and the same speed, if it goes away I would look into the transmission and go forward. If not, I would inspect all u-joints, don't forget the ones in the front axle. If you have a 2 piece rear shaft, check the carrier bearing too. Get your tires balanced and rotated. Make sure the tires are round when they balance them. If it goes away or changes, it is your tires. Next remove the front drive shaft and drive, then the rear shaft.

 

[Hoefler]

New transmission didn't fix it. Now what, I don't know.

 

[Hoefler]

They got hold of a good vibration analyzer, it give no new clues or ideas. It suggests things that have already been replaced. Now they are looking into the front end of the motor per Star's instruction. They will replace the turbo today if it arrives.

 

[JFought]

wow!! i thought my corp. owned dealer sucked!! one time 3 qts low and another time 3 qts high on transmission!!

but this seems crazy, the $ they are throwing at it!!
(if they are putting the old parts back on make damn sure its good before you accept it back!! like a 100 mile drive and trailer pull and ect... . thats what i have had to due to the retarted corp owned dealer here in DFW)

 

[MMeier]

They got hold of a good vibration analyzer, it give no new clues or ideas. It suggests things that have already been replaced. Now they are looking into the front end of the motor per Star's instruction. They will replace the turbo today if it arrives.

Starting to sound like a candidate for the lemon law. How long has it been down now ?

 

[Hoefler]

Been there since 12/16/09, I have 47000 miles on it. I had it in for it the first time at 27000 miles. I don't know if I qualify.

 

[JFought]

you need to check in to it. . thats pretty bad.

 

[Hoefler]

Just heard from the dealer this afternoon, they have it fixed. It was the turbo they tell me. I will go pick it up in the morning and see for myself.