LOST JEEPS
http://www.lostjeeps.com/forum/phpBB3/

Drivetrain vibration above 80 mph
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=21997		 Page 1 of 2
Author:  jburford [ Tue Jun 26, 2007 1:15 am ]
Post subject:  Drivetrain vibration above 80 mph
I have a drivetrain vibration that shows up at 85 mph. It is a little annoying at 85, but it gets worse with more speed. The vibration has a resonance (85, 93, 100 mph). The 85 mph vibration sounds like a hmmm. The 93 mph vibration blurs the rear view mirror. The 100 mph vibration pretty much shakes the whole jeep.

Have any other Liberty CRD owners run into this problem? If anyone knows what might be causing the problem I'd appreciate your input.

2006 Liberty CRD
John B
Author:  bugnout [ Tue Jun 26, 2007 1:36 am ]
Post subject: 
Never had any issues like this, But i've also never had my CRD upto 100. :D

I would suspect wheel balance first. Walk around and see if there isn't a wheel wieght missing.
Author:  flash7210 [ Tue Jun 26, 2007 8:11 am ]
Post subject:  100 mph!!!
Not that its any of my buisness but what are you doing driving at 100 in an SUV!

Anyway, my first thought would be wheel balance.
However, are you running big fat off-road tires on aftermarket wheels?
Big off-road tires can be a pain-in-the-butt to get balanced right.
Also, most dynamic wheel balancers are only calibrated at around 60 mph,
so even if the tire shop does a really good balance there is no garantee
they will maintain that balance at higher speeds.

The whole dynamics of driving change once your speed gets past 85 mph.
No matter what kind of vehicle you are in. Aerodynamics,
wind resistance, tires, wheels, steering, suspension and
road surface are all factors that can effect the handling characteristics
and overall comfort on the road at that high of a speed.

Most vehicles now have a speed limiter that prevent you from driving over
85 mph. And it's not just to please the insurance companies.
Author:  spoonplugger1 [ Tue Jun 26, 2007 10:47 am ]
Post subject: 
I think your rig is trying to tell you something. Tried doing the same rpms without OD engaged under the same conditions to try to isolate the problem yet? You have to try to pick it apart as best you can, this is not rocket science. If it's driveline associated it may show up here.
Author:  skywarn [ Tue Jun 26, 2007 11:29 am ]
Post subject: 
I would put $$$ thats its a wheel or tire...

Ive had mine up to 105 with no issues. But i have my rubber bal. and rotated every 3K miles..

if you have a smooth spot or warn rubber you will get a vib at speeds.
Author:  crdmike [ Tue Jun 26, 2007 11:36 am ]
Post subject: 
I had some intermittent drive train vibrations that occurred anywhere from 70 MPH & up. Since the SunCoast TC though the vibration is gone. It is my opinion that, since it's a SUV, anything past 85 MPH you should expect some vibration issues.
Author:  chadhargis [ Tue Jun 26, 2007 12:34 pm ]
Post subject: 
Quote:
Not that its any of my buisness but what are you doing driving at 100 in an SUV!


I had InMotion remove the speed limiter on mine...I haven't opened it up yet, but it will be interesting to see what she'll do. :)
Author:  Zonie [ Tue Jun 26, 2007 2:26 pm ]
Post subject: 
Had mine well above 100, but only once and not with stock tires. Smooth as glass.
Author:  ATXKJ [ Tue Jun 26, 2007 7:52 pm ]
Post subject: 
Jinstall has talked about running his CRD over 100mph - no mention of vibration problems
(of course it's legal in Germany.......)
Author:  jburford [ Tue Jun 26, 2007 10:52 pm ]
Post subject:  Drivetrain vibration
I do not believe the problem is tires (they are stock for those that are curious). An out of balance tire would have a frequency of 15 to 20 Hz at 85 mph. You can feel that but not hear it (human hearing starts at 20 Hz). The vibration I'm experiencing is much higher in frequency maybe 80 hz or more.

I did notice a post from the gas Liberty forum. The poster was having the dealer replace his driveshaft to fix a vibration he experienced at 95 mph and 102 mph. I did not see a follow up on if the new driveshaft fixed the vibration.

John B
Author:  jinstall [ Thu Jun 28, 2007 11:46 am ]
Post subject: 
It is the driveshaft. DC has a service call on it here in Germany. The dealer here uses 2 hose clamps around the drive shaft starting with the screw heads together. They spread the screw heads away from each other in 2 mm incriments till the vibration goes away. Yes this is what DC says to do as they have found no other way to fix the issue. Mine comes in around 95-105 mph and is worse under deceleration. Above 105 it goes away.

BTW I have not found a speed limiter on the CRD just drag limited, 121mph. Flat or 7% downgrade.
Author:  jinstall [ Thu Jun 28, 2007 11:47 am ]
Post subject: 
ATXKJ wrote:
Jinstall has talked about running his CRD over 100mph - no mention of vibration problems
(of course it's legal in Germany.......)


I have mentioned the drive shaft issue but it was very brief ;)
Author:  ATXKJ [ Thu Jun 28, 2007 2:01 pm ]
Post subject: 
I must of missed that - I do remember something about a 4th to 5th shift at over 100 - no one else had that number.

To the list of Chrysler things I'm not real impressed with - I'll add using hose clamps to balance a driveshaft - I do know folks who've done that - but they typically work under shade trees with a beer in one hand, not at the dealership.
Author:  retmil46 [ Thu Jun 28, 2007 2:08 pm ]
Post subject: 
Add Ford to that list as well. Shop manual for an '81 Ford Courier pickup, that's the approved procedure right out of the manual, although they also mention at the end that at the first opportunity you should have the driveshaft removed and properly balanced.
Author:  jinstall [ Mon Jul 02, 2007 2:59 am ]
Post subject: 
Ihave spoken to a good Jeep mechanic and they have taken driveshafts to get balanced and the issue is still there.
Author:  805gregg [ Mon Jul 02, 2007 9:21 pm ]
Post subject: 
chadhargis wrote:
Quote:
Not that its any of my buisness but what are you doing driving at 100 in an SUV!


I had InMotion remove the speed limiter on mine...I haven't opened it up yet, but it will be interesting to see what she'll do. :)


Where is the speed limiter and how do you remove it?
Author:  jinstall [ Tue Jul 03, 2007 5:25 am ]
Post subject: 
805gregg wrote:
chadhargis wrote:
Quote:
Not that its any of my buisness but what are you doing driving at 100 in an SUV!


I had InMotion remove the speed limiter on mine...I haven't opened it up yet, but it will be interesting to see what she'll do. :)


Where is the speed limiter and how do you remove it?


Why would you want to remove the speed limiter? Also what is your speed limiter set at? Also are your TIRES RATED TO DRIVE THAT SPEED?
Author:  longarm [ Tue Jul 03, 2007 8:05 am ]
Post subject: 
I am having the same problem at speeds as low as 65 mph. My allignment is good, balance is good, tire pressure is good, and still at speeds around 75 mph I feel like my CRD came with massage seats. It's that bad, no kidding. Everything vibrates real bad and it's very annoying. BTW, I am running 255/70/16 Goodyear Wrangler Silent Armors with a 2.5 inch spacer lift. NO, it's not the tires or the lift. I can drive my 6" lifted LJ Rubicon on 35" mud tires at 80 mph and have less vibrations than my CRD.

Anyone have any other similiar experiances to share or ideas?
Author:  chadhargis [ Tue Jul 03, 2007 11:49 am ]
Post subject: 
Quote:
Why would you want to remove the speed limiter? Also what is your speed limiter set at? Also are your TIRES RATED TO DRIVE THAT SPEED?


Because I can and it doesn't cost any extra money. I read somewhere that the stock limiter is set to 105, or something like that. My tires, with proper pressure, should be able to take any top speed the CRD can give them. What's the top speed of the CRD. 110 maybe?? I don't know. Only had it up to about 95.
Author:  jinstall [ Tue Jul 03, 2007 3:55 pm ]
Post subject: 
I have H speed rated tires and I cruise daily btween 100 and 120 mph. I has never gone faster than 121mph in any condition.
Page 1 of 2 All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/