Noise From The Rear

[AngryRB]

Ive had a noise from the rear of the car which has been there for a couple of years, but most recently has become loud enough to be a concern.

Its hard to describe it exactly, it is loudest at around 90km/hr , its pulsing low dull roar sound, im wondering wether its a wheel bearing, cheap crap tyres or a diff thats going, ive jacked the car up and the back wheels are solid.

one point relevent or not, whilst hard acceleration in second i get massive wheel spin which sometimes starts to grip and shake the driveline, and also last time at drags it started gripping during the burnout too,

so question is ... what does a dying diff sound like? how can i distinquish the problem without wasting money...

[GTSBoy]

Dying duffs are more whiney droaney than dull roar. Wheel bearings can roar. Your car is old enough that they could be dead. They are quite good at being stuffed in Skylines without letting on too much.

If you have an original viscous diff with the listed mods above, I'm not at all surprised that you get wheelsping and variable performance from your diff. The VLSD is poor enough with standard power let alone with a lot more. You will benefit from a decent mech diff for drags anyway, so start looking even if the rest of your existing diff is fine.

You should look into new diff mounts and subframe mounts (new Whiteline poly or harder ruber Nismo stuff for street comfort, solid mounts for stiffest location but with poor road noise isolation).

[AngryRB]

  On 27/01/2013 at 3:57 AM, GTSBoy said:

Dying duffs are more whiney droaney than dull roar. Wheel bearings can roar. Your car is old enough that they could be dead. They are quite good at being stuffed in Skylines without letting on too much.

If you have an original viscous diff with the listed mods above, I'm not at all surprised that you get wheelsping and variable performance from your diff. The VLSD is poor enough with standard power let alone with a lot more. You will benefit from a decent mech diff for drags anyway, so start looking even if the rest of your existing diff is fine.

You should look into new diff mounts and subframe mounts (new Whiteline poly or harder ruber Nismo stuff for street comfort, solid mounts for stiffest location but with poor road noise isolation).

Hoping its the wheel bearings, guess they should be replaced anyway, likely to be the originals..

I will look into the diff mounts and subframe mounts cause there is some movements happening at very low speed on a rough bumpy drive way..

So thinking bout diffs, id be after an improvement without any driveability issues like locking up wheels when doing a turn or harsh/rough with street driving, so whilst i will do some research , whats your opinion on a suitable diff ?

lastly, would i benefit from a slight step up in the diff ratio to make my gears a touch longer, eg couple hundred rpms and what ratio would that be?

[GTSBoy]

A 1-way mech diff from Nismo, Cusco etc would be the best way. Will give you more positive drive at the drags and on the street without causing clunks and extra understeer etc etc.

[AngryRB]

thanks mate, your input is appreciated as always

[Jayden.K]

It will be a wheel bearing that noise, they give a similar noise to 4wd tyres, I have a rear wheel bearing noise in my car but won't do anything unless it sounds terrible. It has a roll over noise usually. Jack you car up, drive it to te problem speed and put a stethoscope on the hubs and that will tell you. Btw keep your head low while checking lol

[R32Abuser]

  On 27/01/2013 at 4:13 AM, GTSBoy said:

A 1-way mech diff from Nismo, Cusco etc would be the best way. Will give you more positive drive at the drags and on the street without causing clunks and extra understeer etc etc.

I was under the impression you could only get 1.5 or 2's from Nismo?

[AngryRB]

  On 05/02/2013 at 11:32 AM, Jayden.K said:

It will be a wheel bearing that noise, they give a similar noise to 4wd tyres, I have a rear wheel bearing noise in my car but won't do anything unless it sounds terrible. It has a roll over noise usually. Jack you car up, drive it to te problem speed and put a stethoscope on the hubs and that will tell you. Btw keep your head low while checking lol

yeah im not sure, ive jacked the wheels up and theres zero movement, i guess they could be dry or worn still, the tyres i used to have on the front ( some hero crap) got so noisey i had to replace them, so the back ones are same hero crap tyres so im thinking its an even bet between tyres and bearings, the noise is pretty much always there but loudest on the freeway.

[GTSBoy]

  On 08/02/2013 at 2:15 AM, R32Abuser said:

I was under the impression you could only get 1.5 or 2's from Nismo?

Maybe so. I was just picking a couple of names off the top of my head.

[34GeeTeeTee]

  On 08/02/2013 at 2:15 AM, R32Abuser said:

I was under the impression you could only get 1.5 or 2's from Nismo?

My Nismo was 2 way when i got it but i got it adjusted to 1.5 way, the housings on the Nismo and Cusco (I assume selected models) can be rotated to change the ramps etc.....

The noise you describe mark is kind of what i had when i put the solid locking rings in the rear, it went away when i changed my diff so i can only assume one of the axle bearings in the diff were shot?

As for the shudder on launch that sounds like axle tramp? Mine went away when i did the locking rings etc (mostly anyway)

[Jayden.K]

i have heard tyres that are not even chunky (normal sports tyres) be noisy like a bearing but it seems rare, you could have a noisy bearing for the next 100000km and it wont fail, and as you go faster it will emit a louder noise, special if its a lubrication issue as it gets hot. you wont get play unless the bearing is on its way out, but wear and tear and they get noisy. if it was a soild rear axel its hard to check for play due long solid axel hanging off the end, lucky its not a dirty old holden

[Pattey21]

if its one bearing and not both try cornering hard left or right. If it is the cause, lifting the weight off the worn side will alleviate the noise. I currently have a worn bearing and this is how i was able to determine which side and that it was not a diff noise.

[blueboost20]

Cheapest rear wheel bearings in aus??

[_x_FiReStOrM_x_]

Seen alot of cheap tyres scalloped and giving LOUD noises lately. Check them properly first for sure, if in doubt.. rotate front to back (if possible).