backend whirr

hi all i would like to say thankyou to hippo for his excellent guide on how to change the rear diff mounts it made life alot easier i have put everything back together and taken it for a test drive and i now have a loud whirring noise coming from the back and i am at a bit of a loss to explain it. can anyone point me in the right direction?

thank you

jon

Is the prop shaft rubbing on anything?

Have you tried jacking up both rear wheels and turning 1 to see if you can pin piont the noise? To get the prop to turn jack up 2 wheels on one side and turn the rear. Front will then turn via the props. Just make sure the hand brake is off and the wheels are chocked when trying this.

Is it a droning noise?
Did you jemmy the diff about to fit the new bushes?
If It wasn't making the noise before you changed the bushes, then it has to be something you did whilst changing them.
My dad did mine thinking he was doing me a favour. He pry barred the diff over to make getting the bush in easier and I ended up with a annoying rotational knock at about 30mph +, this eventually turned into a drone starting at the same speed and I have just had to change the rear diff driveshaft carrier bearings which has cured it. if one of your drive shaft oil seals starts leaking then there could be a good chance it may be this.
My first port of call though would be to drop the entire prop shaft to rule out vcu bearings and if it's still there I'd look more closely at the diff......if it is the carrier bearings it would also pay to chage both rear wheel bearinfgs at the same time as 90% of the stuff to do these is removed for doing the carrier bearings

hi prop shaft is off at the moment i have new bearings for the vcu. there was a small noise from the back before doing the mounts and one of the oil seals is leaking are the carrier bearings a difficult job or would it be best to take it to the garage

It's a straight forwards job.
Loose wheels and hub nuts. Get the backed of the car in the air.
Next remove wheels and hub nut.remove the bolt from the transverse link (the long bar that goes from the hub towards the front of the car.......leave it attached at the hub and remove the chassis bolt).
Now remove the other two that come from the hub to the sub frame(just remove the nuts and bolts where they attach to the sub frame).
Finally undo the bolt where the handbrake cable attaches to the chassis.
You can now pull the hub towards you to remove the drive shaft from the hub.Next remove the drive shaft from the diff(I find giving it a tap outwards with a block of wood and a hammer is the easiest way).
Repeat this on the other side and then you may want to suck the diff fluid out of the diff through the top up plug.
Next remove the bolts that hold the diff to the mounting bushes (the six small ones).
You can now drop the diff down quite easily.
It's now just a case of removing the oil seal and then with a small bearing puller removing the bearing........do one side at a time so you can use the other side as a reference for how far the new bearing should be pressed into the diff. Finally fit new oil seals and put it all back together making sure you torque the hub nuts to 400flb and the final torque of the other nuts and bolts should be done with the wheels back on with it in the air on some ramps.

thank you very much i will let you know how i get on

job done it was the rear diff drive shaft carrier bearings thankyou

So shorry should o taken photos but.its straight forwards probably a Haynes 4/5 but in reality a .. 2/3 with right tools inc, torque wrench and bearing pullers,.….. Athlough a couple of bolts a few bits of wood and a bit of steel bar will pull them out no probs if money is tight.........ask if you need to know.....But anyone who's changed the rear diff bushes and then finds a new whirr or knock that wasn't there before haves go you can always ask for advise if you gt suck