Engine / gearbox whine

[Mr2paul]

Hi all. I have a whine I think from the gearbox. Iv changed oil. No issues but this high pitched whine, like you hear in rally cars. Does anyone else have this issue ?

[Gaz mr-s]

A bit more info would help.  Is it in all gears, do you hear it when not in gear,- coasting?

Only when accelerating?  Or on the overrun?

[LeRich]

Is it road speed or engine speed dependent?

[shnazzle]

I think I know the whine you mean. 
One of our 2s had it.
I'm guessing it happens on overrun, when you let go of the throttle?

[Alex Knight]

I think I know the whine you mean.
One of our 2s had it.
I'm guessing it happens on overrun, when you let go of the throttle?

Mine does this with a Corolla T-Sport gearbox also, though it's quite faint.

[Carolyn]

A mild whine can sometimes be cured with an oil change.

Redline MT90 does make a difference. 

[shnazzle]

I don't know the answer but I suspect a bit of gear wear.

Not a scientific conclusion at all but my logic is as follows;

The gears in your gearbox are shaped/rounded such that they have a smooth transfer of power. The tops of each tooth is kind of pointy right?

In race boxes, the gears are straight-cut for faster gear switches in dog boxes etc. As you've said yourself, it sounds like a rally car. They have dog boxes with straight cut gears.

Sooo... If your gears wear, they lose some of that smoothness as they "square". Leading to the whine.

Whether my logic holds is an entirely different matter. Hahaha. I can talk a right load of sh1te at times

I did notice that a good gearbox oil does help

[jonbill]

I think whine on the overrun is often alignment between pinion and the final drive. So could be bearing wear putting them out of alignment.

[mr2garageswindon]

On over run is normally bearings.
At Toyota before 2000 I probably rebuilt maybe 3 or 4 gearboxes (E153 usually) until Toyota decided that quality was less important than price.
From 2000 onward I probably did 2 or 3 a month. It started with Avensis boxes becoming noisy while still under warranty then a few corolla and MR2's all with bearing failure. If left to long the casings become damaged and require replacement.
Normally the noise is so obvious and harsh by then you wouldn't want to drive the thing.
Good quality gear oil may help but it will only mask the initial problem until repaired.

[Nvy]

Compared to something like a honda box, our boxes have puny bearings, plus heat and other stuff its easily to get damaged. When looking at the bearings, the early bearings are open type and the later ones are closed type. The early boxes are failing more which leads me to believe that not enough oil is getting to the 5th gear and the bearings or there is something bad in the design of the oiling system. I have replaced all 4 bearings even tho not all of them were showing wear but still havent fit the box. Other than that the gears are identical to the honda box in width.

P.S. You can try to lug the engine and if you have noise it will be bearings, at least thats what a toyota mechanic told me. Just floor it in high gear when going slow.

[Dev]

 There are two things I have found that can cause a whine that is not input or output bearing related.
  1. Some GL5 fluids like Motul gear oil gave me a whine after about three months as the additives were used up.
  2. You don't have enough gear oil. 
 
 I would start with changing the gear oil with a GL4 oil and it might take some time before the whine disappears so don't be disappointed if it doesn't initially cure it, give it some time to work. Mine went away gradually reducing the sound over time until it was completely gone.


 These transmissions are not bad if taken care of, its just not overbuilt for power as it is a trade off for weight reduction. When you add more power in the range of 180ftlb of torque, that's when things start to go down hill.

[Mr2paul]

Things seem to be ok now 👍 The whine has gone which is odd. It was a zzzzzzzzzzzzzzzzzzzzz noise in all gears so thanks for your help. Dev was correct with the diagnoses so many thanks.

[Joesson]

Things seem to be ok now 👍 The whine has gone which is odd. It was a zzzzzzzzzzzzzzzzzzzzz noise in all gears so thanks for your help. Dev was correct with the diagnoses so many thanks.]


So was it GL5 oil in your box that you have now changed to GL4,  or was it not enough oil and you topped it up?