Fil

sierra xr4x4, i get a knocking noise, from the rear at about 5mph to 25mph then i think its still there but engine noise and speed covers it up?

you can really fell it banging in the car! its coming from the rear?

changed to my 15"s yesterday to eleminate wheels/tyres etc then drove to work, great the noise has gone, but when i drove home it come back agian, it seemed to have got worse

now ive got the rear end jacked up theres no play in the wheels (bearings ) hand brake on or off,

so any suggestions?

ballin

iTrader: (1)

exhaust

mattysxguy

could be the exhaust hitting the rear driveshafts

Fil

nope exhausts well clear off anything, all the mounts are in good condition, the exhaust its solid in its place

Fil

is the diff likely to make a noise like this, ie do they give you a warning, or do they just brake?

Nick-T

I would jack the car up and check the bolts on the propshaft mate. Sounds to me like they've come loose.

SPADGE

Top or bottom rear shock bushes or loose bolts on the same?

Fil

time to jack it up again? just dropped it back on the floor, and test drove, and quess what, no noise again


oh and by propshaft bolts are you talking about the ones that go through the rubber donnut? or something else i should be checking??

Nick-T

Check them all mate, but the common ones to come loose are the four (I can't remember if they are nut and bolt, or if the flange is threaded?) bolts that connect the prop to the rear diff.

SPADGE

The flange is indeed threaded and you need a 16mm socket

Fil

right donnut bolts tight, suspention , bottom and top bolts tight, now goes insearch of a 16mm socket!

Fil

nope the 4 16mms are all tight, dont look good

NMS Badboy^NUTTER^

Also check the driveshafts are tight, and check for play in the diff by trying to turn the driveshafts. Doesn't take much play at all to make a noise

Fil

cant fault it, looks like ill have to try a replacement diff, and go from there?

how much of a job is it to change a diff, thats probably been on the car 17years

NMS Badboy^NUTTER^

Piece of piss basically, just mind you don't drop it on your head

SPADGE

Fook off

xr4x4rs

iTrader: (5)

i had the same noise adnd i couldnt find it on mine either

i checked everything and everything was fine

the only thing i put it down to was exhaust knocking on sparewheel well or the spare wheel jumping lol

Fil

has someone been there done that, doh!

Fil

drove to work and no noise, then drove home thissmorning and its doing it again!? doesn't make i sound when coasting tho??

SPADGE

Yes mate
Have removed and replaced loads of diffs but on this one occasion it decided to fall out and landed on the side of my head Had to have an op to repair a bone near my left eye

Fil

simply put, ouch! hope theres no permenant damage

SPADGE

Did hurt a little and locked my jaw so i could only just get a fag in my gob but couldn't winge too much
No permanent damage to my stunning looks just a small scar about an inch long near what would have been my hair line where the surgeon inserted his tyre lever

James

i had a similar problem on mine, nasty knocking noise when pulling away. turned out that theres a threaded section on the prop with a 36mm[iirc] nut wound onto it, it was only hand tight to i tightened it up and locktited it to be sure and it did the job.

i think it's just after the centre bearing.

Fil

how warm should a diff get, on a short run? should it even get warm? say after 7/8 miles of 30mph tops taking it easy?

Fil

hmm seems a previous owners mullered the allen key oil plug nut! doh, have got a seringe ready to try latter and get some oil in via the breather pipe