Car whines worse than my dog - (after track day diagnosis)

[1JZ-Rolla]

So......... I spent the day pedalling the corolla around Wakefield Park yesterday, in rather hot 33 degree conditions.

Heading home from the track, I noticed a whine from the rear-end, which is only present under load (anything from light acceleration, but no noise on deceleration/coasting).

I run a synthetic diff oil, which I would have thought could take the 6-lap sessions without seriously overheating, but dropped the oil tonight anyway to check. There is the usual amount of fine metal paste on the magnetic drain plug, but the oil is the colour of coca-cola.

My question is, how can I tell if its the diff itself, or a wheel bearing? I've put fresh oil in the diff & tested tonight, noise is still the same.

The diff in question is a complete axle assembly from an MX13 corona (F-series) with Torsen LSD centre & standard 3.9 gears. Bearings are upgraded to an oversize set intended for the G series hilux, and a solid crush tube has been fitted on the pinion. Has done less than 6,000km.

Any ideas appreciated!

Cheers
Phil

[Silly Rabbit]

...me thinks the diff is stuffed.......last time I took my TA22 out at Phillip Island it made that noise after and whined all the way back to Melbourne......2 days later on my way to work in it .*BANG*......diff gone and no drive........late last year started to have the same whine on the way up to Winton and this time a minute later the diff went bang again...........looks like it is time to drop the centre out for a proper inspection............I would hope its a wheel bearing but I think the track work etc makes a diff whine more a possibility.......fingers crossed for something easily fixable for ya

[oldcorollas]

check the tooth engagement with .. yellow paint or whatever.. if the engagement is ok, and backlash is ok....hmm

[The Real Roadrunner]

if its lash then it will do it both ways generally.
if its a wheel bearing you will hear it changing tone as you load individual wheels ie turning left then right the noise should change.

the pinion may be riding high or low on the crown wheel but thjis is something best left to an expert to make adjustments.

if you need an Fseries centre i may be able to locate one for you, what ratio do you need?

cheers
linden

[Rinmax]

Have you tried upsetting the dog a bit more. You know give him a bit of a poke, take your time feeding him, or just don't give him any tummy rubs.

This could make him to whine more, therefore, it will be worse than the car and you won't have to worry about it any more. All fixed.

Seriously though, it does sound like the diff, not the bearing. I used to use my JZZ30 for trackdays, unfortunately it too develop a bit of a whine after a day of abuse. A few weeks later I had to put a new center in.

I hope that's not the case with yours. Good luck.

[1JZ-Rolla]

Haha, Rinmax, you're a funny bugger aren't you?


Now i'm going away to cry, as i've only just recently spent over a grand on bearings & labour alone for the diff centre

[Gavatron]

Got warranty? Just don't tell them it happened at the track

[oldcorollas]

maybe it has just "settled in".. ie the bearings are shifted a bit from where they should be?

[lexsmaz]

Doesnt sound good, axle bearings wont change in noise level, if you are driving in a straight line & just on and off the throttle ..
Did you let the diff bed in before you went racing, from memory around 600 - 1000 km normal driving needs to be done, they set the bearing preloads higher for new bearings allowing for them to settle in, which in turn creates quite a bit more heat & if you have given it a hard time to early the bearings could be damaged .....

[Rodger]

Jeez Phil,

Not a very comfortable sound

Come for a ride on the street in the '22 I bet it whines louder. I know when I am doing 80 or 100ks by just the pitch of the whine.

But I/we did not hear it when fanging around Wakefield. Always been there always will until I change it or get it set up again. One of our Diff places in Canberra will need to check yours.

It is in the gear mesh as stated above. If they are not quite right and then they experience a track day and some temp, they wear just enough to be noisy. A bit like the sound most diffs make when reversing.

Regards

Rodger

[gianttomato]

Typically what happens is the oil runs down the axle tubes during cornering. This leaves the diff "starved" of oil. Bearings in the diff crap out. This results in more moaning from the diff than a two bob hooker.

I did two diffs this way at the Island. Big long sweeping high speed corners are the killer.

When you rebuild your diff, I suggest baffling the housing. Inside the housing, you will notice a metal plate on each side where the axle tubes enter. Take them out and weld a piece of exhaust tubing to each one, just enough tubing so when you put them back in, the diff still slides in and out easily. Then use some heatproof sealant to seal the plates in place. The seal doesn't have to be perfect - you just want to reduce the size of the gap so the diff oil doesn't migrate down the axle tubes so easily. Since I did this, no more diff crap outs.

[allencr]

if its lash then it will do it both ways generally.
if its a wheel bearing you will hear it changing tone as you load individual wheels ie turning left then right the noise should change.
the pinion may be riding high or low on the crown wheel but this is something best left to an expert to make adjustments.

Thanks!! Is there anything that the lash/back lash does other then locating the pinion & ring/crown wheel contact patch during deceleration/engine braking?


1JZ-rolla, the coca-cola colored oil, is that significant???? Does it have a burned smell or a great change in color/fragrance from last inspection or when it came out of the bottle?

[1JZ-Rolla]

yep, definately enough km on the diff to bed in.

[1JZ-Rolla]

Typically what happens is the oil runs down the axle tubes during cornering. This leaves the diff "starved" of oil. Bearings in the diff crap out. This results in more moaning from the diff than a two bob hooker.

This is quite likely, as the MX13 housing has NO baffling at all from memory inside the axle tubes. My previous T series housing did, and I remember wondering why this one didn't.

JZ-rolla, the coca-cola colored oil, is that significant???? Does it have a burned smell or a great change in color/fragrance from last inspection or when it came out of the bottle?

The synthetic oil was a nice straw colour when it went in, and black enough to not see through now. Diff oil stinks regardless to me, so hard to tell if its burnt over the general stench

[WDE_BDY]

Typically what happens is the oil runs down the axle tubes during cornering. This leaves the diff "starved" of oil. Bearings in the diff crap out. This results in more moaning from the diff than a two bob hooker.

Starlet diffs (U code or X code) apparently have the same problem on the circuit, one solution is to overfill the diff by jacking up one side of the car and filling through the axle tube or you could top up through the breather too. Does tend to put extra pressure on your axle seals though so make sure they are in good condition.

Callum