Mud-club

Vehicle & Technical => Range Rover => Topic started by: tack43 on December 04, 2012, 16:05:10

Title: Noise/vibration
Post by: tack43 on December 04, 2012, 16:05:10
I have a noise/vibation on my 1990 3.9 auto with BW transfer box. It sounds like I'm driving on one of those motorway rumble strips. It happens around 30mph quietly and between 60 & 70 mph loudly on light acceleration/constant speed but goes on overrun, brisker acceleration. I've checked all the usual suspects (wheel balance, play in moving parts etc) and substituted the front prop for a known good one. I can feel vibration though floor and accelerator pedal but not brake pedal or steering wheel. Seems to be coming from the front. It's gradually getting worse/louder. Any ideas anyone?

Cheers
Title: Re: Noise/vibration
Post by: lambert on December 04, 2012, 16:30:47
Beyond prop joints I would suggest prop being phased correctly? Or gearbox t box but I don't know enough about the bw to comment.
Title: Re: Noise/vibration
Post by: JIMBOBLY on December 04, 2012, 23:11:17
the borg warner transfer box has a chain,it may be that loose/stretched,or could be the bearing on the output flange for front prop
Title: Re: Noise/vibration
Post by: Range Rover Blues on December 05, 2012, 16:07:26
Is it lifted or not?

Does it happen in all gears or is it worse in one particularly?

Did you drive it with the propshaft removed altogether?

Is it misfiring and have you checked for compression?
Title: Re: Noise/vibration
Post by: tack43 on December 08, 2012, 23:40:27
Thanks for the replys. prop should be in phase as it hasn't been moved and was ok prior to problem. bearing or chain sounds good for a potential problem - would it have play? is it usual for bearings to have a resonant speed?
It's fitted with H/D springs red/white rear and diesels (blue/green?) front with De Carbon shocks no ARB - so an inch or so I guess.
No haven't driven it without props
At 30 gear is 3rd, 60 4th. when accelerating vib goes so doesn't show in lower kickdown gear
compression in normal range no obvious misfire. running on gas so misfires normally obvious
Title: Re: Noise/vibration
Post by: MuddyMike on December 09, 2012, 09:23:08
Could be the tyres, some suffer with what the trade calls "blocking" when the blocks of tread wear unevenly.Try stoking the tyre with your hand, can you feel uneven tread blocks. Only real test is swapping wheels.

Could also be front end of rear prop. Try removing it and going for a drive, remember to engage dif lock or you won't go anywhere!

Mike
Title: Re: Noise/vibration
Post by: tack43 on December 09, 2012, 16:18:46
Thanks. Tyres are ok. still need to check prop while removed.
" Engage diff lock" - Haven't got one it's a BW transfer box.
Title: Re: Noise/vibration
Post by: James.Harwood on December 10, 2012, 19:04:33
Won't be the chain, they make a very harsh knocking noise when knackered, most obvious under hard acceleration.
Title: Re: Noise/vibration
Post by: tack43 on December 22, 2012, 17:28:11
Seems like the A frame bushes are shot. Have been noticing a bit of wobble on the back. Haven't been able to check properly as I'm using my axle stands on the rebuild. No doubt the A frame ball joint could do with renewing too! There's no play but the self leveler is pushing on the joint. Wonder if this could be causing the vibration as the diff nose looks lower than it should be and could be impacting on the rear prop. Another job for the New Year!
Title: Re: Noise/vibration
Post by: Range Rover Blues on January 24, 2013, 14:22:09
COuld be a prop UJ, also check the handbrake isn't binding, though I thnk it unlikely it's an easy fix.
Title: Re: Noise/vibration
Post by: tack43 on January 31, 2013, 23:49:33
Changed the bushes but unable to get ball joint/self leveler off. May need to cut a hole in the floor to get at the top bolts. The leveler BJ's are shot - bottom is completely seized and top has loads of play.
Had a bit of death wobble - found play in track rod BJ and drop arm BJ. Changed but it's getting worse to the point I don't want to drive it and haven't got time to get under it - I'm at uni and have lots of achedemic s**t to do - will have to use the car for a bit. Will update when I can.
Title: Re: Noise/vibration
Post by: Range Rover Blues on March 23, 2013, 18:12:34
I have a big problem with death wobble too.  I only get it on ABS cars so I think it's something to do with the top bush, unlike a non-ABS car you can't adjust the wear out of the bush pin.

As a quick "fix" you can set the front end toe-out a bit and fit stiff dampers.  Make sure all ball joints are good and nip up the steering box.

Also check the steering damper, ours is so bad it broke the steering damper bottom bracket.

Also check radius arm and panhard rod bushes.
Title: Re: Noise/vibration
Post by: tack43 on May 05, 2013, 11:25:40
Well seem to have got to the bottom of the vibration but don't understand why! It seemed to start when I fitted HD front springs. I've gone back to standard springs and the vibration has gone.  :azn: Steering damper was shot so replaced and no more death wobble.  :azn: Still got the A frame ball joint and leveler to sort out and that can only improve things even more.   :cheesy:
Title: Re: Noise/vibration
Post by: Range Rover Blues on May 18, 2013, 11:11:35
Good news!

Has fitting the old springs changed the ride height AT ALL?  if they are the only things you swapped then it suggests a propshaft UJ still.

Also, could the springs have had any effect on the death wobble?  I'm asking because I still haven't cured ours.
Title: Re: Noise/vibration
Post by: tack43 on May 21, 2013, 22:02:02
Ride height has been reduced by about 1/2" - only noticeable on measuring. Prop is fine I took it of my other RRC which has a 2" lift and no vibration. Still need to adjust N/S swivel preload as it's a bit loose but the shot SD was not helping!
Got a new problem now. The brakes were fine when I parked it up in Feb but now it feels like it's got a warped disc - feed back on braking. It's got ABS and I changed the rear calipers in Jan - I used a pressure bleeder but wondering if air is in the system. I can't see a disc warping it's self sat on the drive!
Title: Re: Noise/vibration
Post by: Range Rover Blues on May 28, 2013, 02:52:11
I've had that.  If the disks rust then they will judder, the surface gets ruined in the portion exposed to the air and doesn't rust between the pads.  Total pain becuase skimming them is the only real fix.

If you lay one up for a while it's worth pushing the pistons right back in so the whole disk surface can breath.

Using them just made them worse.

If I get chance this summer I'll put them in a 4-jaw and work, mine were EBC vented/grooved and cost a good few quid.
Title: Re: Noise/vibration
Post by: tack43 on June 01, 2013, 23:06:44
More work to do then.  :undecided:
Title: Re: Noise/vibration
Post by: tack43 on June 13, 2013, 23:09:16
Got a new problem now. The brakes were fine when I parked it up in Feb but now it feels like it's got a warped disc - feed back on braking. It's got ABS and I changed the rear calipers in Jan - I used a pressure bleeder but wondering if air is in the system. I can't see a disc warping it's self sat on the drive!

Seems like it was a fractured break pipe! Fixed and now ok.
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