Questionable Gearbox Noises

[GSRSOL]

Hey all,

Not sure what im hearing, so hopefully someone here does!

When im driving, in high gears (3 4 5), and back off the throttle and roll for a bit in gear, then touch the throttle lightly again, i hear a distinct repetitive 'scratching' noise that keeps going until I hit the gas harder.....

otherwise if i keep the pedal at that level of depression which the noise is heard, it will just keep going....... it isnt loud, just worrying

does anyone know whats going on?

Anyways, i only hear it when driving the car like a grandma...... most of the time the pedal gets depressed to quick too hear it.....!

thanks,
Dan

 

[CLuTZ]

Whining transfer case?

when was the last time you changed your g/box, transfer AND rear diff fluid?

 

[JSTYLE]

drive your car up to 80km and put it into nutural.. if u hear the same noise then its your wheel bearings.. from what your saying it sounds like wheel bearings.

Jon

 

[Sloth]

Wheel bearings tend to make a low grumbling noise.

Get wheels of car off the ground. Grab the top and bottom of the wheel & wiggle it. Can you feel movement?? If so, wheel bearings.

 

[GSRSOL]

Thanks for your help,

In neutral at 80kph the car sounds fine, and there is no movement in the wheels whe they are off the ground.........

The sound is more like what you here when the car is about to stall, that shuddering/ scratching noise....... except when your moving....... i had originaly thought it was something to do with gearbox/drivetrain, but dont know enough to be sure.......

i dont know how long ago the gearbox, transfer and diff fluids were replaced either! maybe thats a good start....... which oils do you guys use for the above?

 

[jase]

word on the street is NOT to use redline.

castrol is apparently the one to get but i cant remember what type.

will find out this week tho

 

[GSRSOL]

Thanks for the tip Jase,

What oils do other people use for Gearbox, Transfer and diffs?

 

[dougo]

mmm i had something like this happen with my old lancer. back off the gas and i would get a flutter like noise. i think it was bearings?

 

[GSRSOL]

yeah like a scratching flutter.......... i assume you mean wheel bearings??

but then again if it was wheel bearings wouldnt it happen all the time?

 

[Andrewv]

I have a car that has a similar noise. It sounds like the exhaust is having a vibrate from about 80k down at light throttle and over run. Afte having a look inside a gearbox I recon it is the bearings on the shaft that runs the crownwheel. Once the bearings have a bit of wear then under no load there is a bit of backlash between the 2 gears and the gears rattle together. Is your noise better when everything is cold ? I am going to do the bearings in my box in a week or so and will let you no what I find.

 

[dougo]

GSRSOL i meant gearbox bearings sorry, they were just a bit noisy. sorry should of made it clearer

 

[GSRSOL]

Thanks dougo and andrew........

Gearbox sounds more like it......... the noise is better when everything is cold too. Does this mean i need to have the gearbox rebuilt?

dan

 

[Andrewv]

I would guess so . Give me a couple of weeks and I will do mine and let you know

 

[dougo]

noisy bearings isnt a terribly bad thing though?? sure it would be nice to get some new ones in there! but is it that big of a deal. :?:

 

[PASHN8]

word on the street is NOT to use redline.

castrol is apparently the one to get but i cant remember what type.

will find out this week tho

What is wrong with Redline?

 

[jase]

i've just been told by a few of the rally guys thats it's just not worth the money

i'm catching up with an ex-ralliart mechanic tomorrow.. i know he doesnt like redline - i'll ask him what he suggests

 

[Andrewv]

The bearings can only get worse and then fail. If it fails then yes it is a very bad thing !

 

[GSRSOL]

yes well, dont want that to really happen now hey....... lol

what oil should i put in it then (gearbox)? would any specific one help, or reduce the problem?

Its not that big a deal, its just one of those 'little things' to add to the list of 'little things' that really shit me while im trying to enjoy a 'spirited drive in the countryside' ....... :wink:

Thanks heaps peoples
Dan W

 

[jase]

hey lewis, if you're reading this, post up what oil les uses :lol:

shell or something? it's something that not many people use, and it's supposed to work a treat

 

[PASHN8]

Redline Lightweight Shockproof is fantastic stuff, I know because i've trialled about 3 different oils over about 20 of my cars i've owned.

I spoke at length with Jim Berry from Race Clutch in QLD, and he advised NOT to use Castrol Syntrax as its too thin, and advised Redline, as did Ben from Race Pace in Melbourne who builds and tunes some of Australia's quickest GT-R's and Supra's.

Motul Gear 300 is meant to be good too, but I haven't had any personal experience with it so i'll refrain from approximations.

Dino.