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Help - Vibration can't get rid of it !!
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=1&t=68988		 Page 1 of 1
Author:  Pippobug [ Sun May 27, 2012 7:27 am ]
Post subject:  Help - Vibration can't get rid of it !!
Hi

I really hope you can help as this is driving me mad.
As some of you know I have a KJ 2003 (Oct 2002 build) CRD 2.5 and I have lifted and I run 245/75R16 tyres.
My lift is as following and has been on my KJ for just over 16K mls:

Front:
OME 790 & NS 131 + Boiler 3/8 top plate – Sitting at 22 inc

Back:
OME 948 & NS 132 L + NOW 1 top isolator (had 2 taken one off I will explain) – Sitting still at 22 inc

My problem is as following: I have a vibration coming through the KJ once I am in in top gear (5th I am manual) once I start hitting 70 mph and it gets stronger & louder the faster I go. It’s also happens if I put my foot down accelerating and I rev the engine over 3000 rpm through the rear but more apparent in 3rd, 4th and 5th at speed. If I keep it under 70 mph it all runs smooth enough, but as soon as I pass that it start.

I used to have this slight vibration in 4th between 1800 to 2000 rpm but somehow taking the 2nd rear isolator has stopped that. The KJ now feels a lot smoother when accelerating, but once I hit the 70 mph id start coming back.

Now to date I have changed:
The back
Front & back CV joints with grease able ones
All the bushes for the Rear Upper A Frame – All New
All the bushes for both Low Control Arms

The front
All Lower Arms Bushes front & back + New Caster Bolts
Upper Arms are from JBA 4.5 (came new)
Changed one front passenger side wheel bearing, other still is good and not making noise at any speed (at least I can’t hear it)

So in summary I have nearly changed all the suspension bushes on the KJ ( missing the sway bar one at the front but I really don’t think they are the cause of my vibration at speed), my mechanic has checked all the engine & gearbox bushes/support to see if any needed changing but all are good and tight. The gearbox is in order as works well (except when cold between 1st & 2nd and I have changed the oil there twice now) I have had a new Clutch fitted less than 16K miles and it doesn’t slip or make noises.

One last piece of information, I have/still have problems with the front alignment but the KJ goes straight and doesn’t pull to the right or left to much. See attached last report done now 7K mls back:
Image
And yes I will be taking it back to be re done once I have managed to sort the vibration out once and for all.

My mechanic tell me it might be caused by the rear prop shaft working still at a far too high angle under stress, therefore it might require re balancing or still drop the back by another Top isolator. Here at Lost some members run the rear at 23.5 inc I assume without any problem or vibration at speed, so please what is going wrong here and what do I need to do to resolve this.

Please can someone help me figure out what it is please, it’s driving me mad….
Thank you for your help,

Fil.
Author:  papaindigo [ Sun May 27, 2012 9:22 am ]
Post subject:  Re: Help - Vibration can't get rid of it !!
You might want to check for failed drive shaft "U" joints, may require dropping drive shaft to properly check as they can be hard to see/diagnose on the vehicle. Just a thought though.
Author:  Pippobug [ Sun May 27, 2012 12:32 pm ]
Post subject:  Re: Help - Vibration can't get rid of it !!
papaindigo wrote:
You might want to check for failed drive shaft "U" joints, may require dropping drive shaft to properly check as they can be hard to see/diagnose on the vehicle. Just a thought though.

Hi,
having changed the UJ joint, what part of the back properlar joint should be checked to see what is damaged or worn out and needs to be replaced? would i need to buy a new rear propshaft? also would I be better replacing it with one from a V6 I understand they are different, might it do the job better?

Fil.
Author:  2006 KJ [ Sun May 27, 2012 3:27 pm ]
Post subject:  Re: Help - Vibration can't get rid of it !!
like he said.. could be U joints. could be tires or bent wheel. Is it in your seat or steering wheel? If it's steering wheel it's in the front end/front tires/wheels.... if the shake/vibration is in your seat or floor it's probably rear end/tires/wheels. If your pretty sure it's in the rear end maybe check the bearings?
Author:  Pippobug [ Sun May 27, 2012 3:47 pm ]
Post subject:  Re: Help - Vibration can't get rid of it !!
2006 KJ wrote:
like he said.. could be U joints. could be tires or bent wheel. Is it in your seat or steering wheel? If it's steering wheel it's in the front end/front tires/wheels.... if the shake/vibration is in your seat or floor it's probably rear end/tires/wheels. If your pretty sure it's in the rear end maybe check the bearings?

Hi
It's not the front as i don't have vibration in the steering wheel. The vibration feels like it's coming from under the driving seet. I have changed both UJ on the propshaft less than 1k mls ago and they are the correct part numbers.
I have also just rotated the tyres about 1k mls ago and the syntoms carry one so i don't think i have a bad tyre/wheels.
Fil
Author:  WolverineFW [ Sun May 27, 2012 11:32 pm ]
Post subject:  Re: Help - Vibration can't get rid of it !!
Might be a long shot, but bent and/or unbalanced driveshaft?
Author:  Pippobug [ Mon May 28, 2012 2:43 am ]
Post subject:  Re: Help - Vibration can't get rid of it !!
WolverineFW wrote:
Might be a long shot, but bent and/or unbalanced driveshaft?

Hi,
that is what I have been told by my mechanic too, but even he isn't 100% sure. I am going to see how much a new driveshaft is going to cost or if I find someone that can re balance it.

But if that fails to sort the problems, what next please?

Any more possible causes?

Fil.
Author:  ando [ Mon May 28, 2012 4:40 am ]
Post subject:  Re: Help - Vibration can't get rid of it !!
Hi Fil, I had a similar issue when I lifted my old XJ (4.75 inches) .. and had the tranny case lowered by an inch to settle it back down which worked a treat ..... not saying its the prob here, but vibe at a certain speed, and it "feels" a bit like there's flex in the rear prop under power if its what I'm thinkin ??

My money would be on the prop being out of balance after the lift, or possibly play in the prop bearing either end maybe ? :?

If the UJ's are good, and tight, then it surely has to be "play" somewhere, or a balance issue at speed ?
Author:  Pippobug [ Mon May 28, 2012 10:03 am ]
Post subject:  Re: Help - Vibration can't get rid of it !!
Well found a shop that deals specifically with Propshafts & CV/UJ and I am now taking it to them tomorrow to be inspected, I will keep you up dated.
Fil.
Author:  ando [ Mon May 28, 2012 3:02 pm ]
Post subject:  Re: Help - Vibration can't get rid of it !!
Good luck mate :wink:

I'm in a similar boat with this darn ticking noise I've still got :x .. the garage I use, has taken the turbo off on my instruction and found the oil return pipe seal has gone which I guessed was the case, but its doubtfull thats the cause of the noise unless it was a BAD leak and allowing crankcase noise out once everthing expands with heat :? :(

Need to find somewhere else to take it really if the ticking is still there when I get it back Wednesday :roll:
Author:  Pippobug [ Fri Jun 01, 2012 2:50 am ]
Post subject:  Re: Help - Vibration can't get rid of it !!
Hi,
well took my rear propshaft to the shop to have it looked at and fixed and now I have it back.
Looks like there were two things wrong with it:
1) the UJ at the gearbox end had a slight play in it, so they added a a thicker ring to both sides and stopped the movement. The UJ was new and has less then 1000mls on.
2) looks like it was out of balance at the top end where it attaches to the gearbox buy something like 37 gr and at the other end by 15 gr, they shave & added and rebalanced it all to compensate (comment from shop it's nearly balanced to a sportcars standard).

Cost £100.00 ( $150.00), result NO Vibration at all at speed ..... and I am very happy again and my KJ performs at it should now ( ...well nearly still have to finish sorting Tracking & Camber this wkd)

Thank you to all for you help and advise.
Fil.
Author:  ando [ Fri Jun 01, 2012 4:33 am ]
Post subject:  Re: Help - Vibration can't get rid of it !!
Great news Fil :D .... glad to here someone is havin a bit of success with annoying issue's !! :(
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