January 24, 201412 yr Ok so last week i had this knock coming from the rear. I thought it was jack in the boot being loose and knocking against body- nope. It came back :( i try to give more info- it doesnt knock driving over rough road- bumps, potholes etc. its more related to forward-backwards movement. And defo linked to accelerator/ brake. Lets say im getting to junction, letting go off the throttle so engine brakes a little- knock knock. Pressing brake - nothing. Then moving on- clutch, accelerator soon as it moves - knock. Drives me nuts. Doesnt knock everytime tho. Just sometimes more audible. Its coming from the rear, tried rocking both wheels no play. Shocks are good. New brake pads. Was thinking about 2 things- exhaust ( tried shaking it- nothing) or drop links? Someone please help
January 24, 201412 yr I'd whip the wheels off the back pull the pads out and some copper grease behind them pull the pistons back in then put them back. While it's jacked up with the wheels off get some of this http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_214714_langId_-1_categoryId_255223 Spray load's of it into your hand and go bash one out....Oppps thinking out loud. I mean spray on the suspension replace it all and take it for a drive see if it does it anymore. If it does I'd say its the rear diff bushes. Not sure if there is an additive you can maybe add to help the diff or not I know you changed the oil. Not left any tool's around ? :D
January 24, 201412 yr Did you have the noise before you changed the diff oil ? Maybe you didn't tighten something / disturbed something whilst tinkering . my first guess (seeing as tried zorst and shocks) would have been gear box stabiliser ("dog bone " mount at the top of the gearbox) or engine mount, due to it happening during engine brake are you sure it's coming from the back ? Maybe get someone in the back to try to narrow it down Otherwise mabye try checking for worn bushes around the propshaft uj , drop links ,diff braces ect . it's probably something minor....... mabye just get a 3" decat you'll never hear it again :-D
January 25, 201412 yr Worn diff bushes perhaps, making the diff slide back and forth on acceleration and braking.?
January 25, 201412 yr Author ok so bit of an update. i think i narrowed it down a little, i think i went under the car today but couldnt see anything obvious. everything is nice and tight, no movement. backbox moves a little when you shake it but has enough clearence not to knock against anything there. so i suppose thats pretty normal. this knocking is intermittent but when its there its double on engine brake and single on moving on from low revs. its not related to brake pedal. and its defo coming from back. i dont think its antiroll bar bushes as they would knock on rough road. this is not affected by surface car is driven on. As Tlag says its more back-forth movement of the car. rather then up and down. So what we come down to is - Diff bushes/braces and propshaft. Possibly exhaust ? Its definately something knocking on chassis/body. It drives me crazy. Can someone shed some light please on potential cost and repair difficulty ? Not a right time for any costly repairs atm for me i am afraid :( thank you for advices lads :)
January 26, 201412 yr As you have checked all that I would be bolting a go pro underneath and taking it for a drive to see if anything moved prior to going into a garage...?
January 26, 201412 yr Author Another update... It got worse :( last nite it was knocking continuosly. When i let go off throttle pedal at round 2500 rpm it goes knock knock knock knock ive made video of it i need to edit it and posted here :( not a happy bunny :(
January 26, 201412 yr Author It was phone in the boot and the knocking is in second half of the video
January 26, 201412 yr Author Try this instagram only allows 15 sec video upload https://www.facebook.com/photo.php?v=10202019887637175
January 26, 201412 yr Author right getting somewhere now. im sorry for being a pest on here just trying to get down to something. check this out http://www.iwsti.com/forums/drivetrain-components/25833-rear-diff-clunk-knock-3.html
January 26, 201412 yr Yeah works now you can send it to me if you like and I will upload it to youtube but worked fine for that time. it did sound like an exhaust blowing too but did hear a faint clonk now and again.
January 26, 201412 yr the links worked for me also - hear a faint clunk - I dont think it is consistent enough to be in the diff itself or a bearing as they tend to be more cyclic or grinding - Has the rear suspension scooby knock been ruled out??
January 26, 201412 yr Author definately ruled out Jay, this hapens on smooth straight road, no bumps, potholes etc i checked shocks and they are fine, no play, no clunks over rough road. found this on one of the forums http://www.iwsti.com/forums/drivetrain-components/25833-rear-diff-clunk-knock-2.html
January 26, 201412 yr Trunk clunk eh - are you going to try the reverse then 1st to 2nd shift like the chap suggested?
January 26, 201412 yr Author no no but if you look at that link on first page my symptoms are exectly same as the first chap described. i was reffering to what they say about owners manual thing
January 26, 201412 yr Just might be one of those things. So in that case I'd say turn the music up louder or bigger exhaust like said before ;)
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