Strange noise when driving after changing diff...HELP please

[brad 93hilux]

hi i reciently had a lockrite in the front of my hilux with 4.3 centers, i changed diff centres to 4.8 and took the lockrite out of the 4.3 and put it in the 4.8 which is now in the rear.

After i re assembled it wich all went good (checked back lash which was ok) i took it for a drive and found the lock rite working ok BUT once in second, third, 4th etc there is a fairly high pitch wine which sounds like tyre squeal but gets louder with accelleration.

As you accellerate the noise starts when you take your foot off the accellerator it instantly stops. There is no vibration jst the noise....

Does anyone know wat this would be?
I have no idea except uness the diff crownwheel/ pinion preload is all wrong ?

Any help is appreciated Cheers

[Evil 73]

Did you put diff oil in after swapping centres etc.....?????
Cos that sounds like bearings under load with no oil, i may be wrong, but i bought a cruiser once that had no diff oil in the rear diff and under acceleration it screamed its arse off, but when you backed off and coasted it almost stopped but you could still hear it a little.

Ben

[simkell]

sounds like back lash is to tight or to much bearing preload on the centre.
might be worth pulling it back out and double checking that everything is alright.

[4sum4]

Did you put the shaft back together proply (yoke ears line up?)

[brad 93hilux]

i definately put the oil back in, i was thinking bout the preload,,,, have to pull it out again i guess and have a look.

it seemed ok before i put it in but must not have been..



Cheers

[brad 93hilux]

and yes the shaft definately was put back correctly, i had to put a different cross shaft in the centre as the one that was origionally inthe diff had .15 wear and in the specs for the lockrite it says no more than .02 wear...

Don't know if thais would change anything...

cheers

[Pauwolf]

if it is whining, the reationship between crown wheel and pinion is wrong. the pinion will have to be moved in or out by taking away or installing shims between the bearing and the pinion head. I recon it diff shop time, it should not be that dear, I got the last one done for under $200 if you have all the bits

Paul

[bazooked]

its the preaload on ur pinion bearing, its to tight, back it os a bit and take it for a spin, iit still does it repeat above.