Diff oil to quiet diff whining

[alcyon]

Ok I know what some of you will say, rebuild the diff properly. I did, 7 times, and changed Ring and pinion twice, brand new OEM gearsets. The diff is a IRS mk3 Supra 4.556 ratio , 9 pinion , 41 tooth ring gear.
To cut a long story short, I experimented with various pinion depths and pinion preloads, and found that the diff worked better with a high pinion preload, high end of the acceptable scale of TOYOTA TSRM.
My current iteration of this rebuild, had the pinion run a little shallow for the first 1000km of light break in. Pinion depth shim 1.9mm. The gear pattern looked good but it whined at 60 to 70kmh. I proceed to deepen the pinion depth back to stock shim of 1.94mm. The results are the same. The pinion preload is not low or loose. It is still tight and within spec. But on light throttle at 60 to 70kmh, the whining is at it's loudest. When I let off the throttle, it is virtually silent. I tried various GL-5 Gear oils from Toyota 85W-90, Mobil HD80W90, Mobil HD 80W90 + 25% Lucas Oil Stabilizer, and just recently Lucas Mineral 80W90.
With the lucas, there is 20% reduction in the sound. The Lucas 80W90 seem to not thin as much as the Toyota 85W90 and Mobil HD80W90.
I am looking for a 50% reduction of this whine on light throttle at 60 to 70kmh. To be clear, there is still a whine over 70kmh but the faster I go the fainter the sound gets.
I was thinking of trying a few oils.
1. Lucas Synthethic 75W-140
2.Shell Spirax 85W-140
3. Using Plain old 80W90 + Motorcraft XL-3 additive, some people have said it reduced the ring and pinion noise

I want to try to avoid using 140 weight diff oil if possible, as I think it would be like driving the car with another 70kg me in the passenger seat.
I know most of you will say diff oil wont make a difference, but a lot of people sweared by Specialty Formulations GL-5 oil which is now unavailable.
Let me know what worked for you.
Oh yes, Amsoil severe gear 75W110 did nothing on 2 previous rebuilds.

 

[V70tdi]

I dont got any luck with get a noicy diff to be quiet with any oil. Gear grease made the best to get it quiter for a short time but nothing i will put in a diff i would be running for a long time.
Just get it rebuild the correct way. Something is not right if it whining is what i learned the hard way.

 

[goingplacesanddoingstuff]

If Amsoil doesn’t do it, probably nothing will. It keeps temps lowest. Amsoil quieted my Tacoma diff. The only other thing I might try is stepping up to the 140 weight Severe Gear. If that doesn’t work, who knows, maybe the 90 weight will help.

Diff noise is caused by harmonics. The fluid only has so much influence on that, but all you can do is change stuff and see.

You could also try HPL.

 

[SwampSurvivor]

I put 120,000 on the whiney 8.25 differential in my Jeep before I tore it apart to regear the Jeep. That always made a LOT of noise.

When we tore everything apart, nothing looked like it had 215,000 miles on it. It looked like a 50K mile differential. Pinion bearings felt nice, carrier bearings looked great and no weird wear patterns visible on anything.

 

[wings&wheels]

I had a slightly whiny diff on my diesel Rover and Redline Shockproof quieted it a bit. Tried it on a whim and it did make a noticeable difference.

 

[PontiacHO]

Unless your vehicle has sound deadner like a Lexus, you’re going to hear that 4.56. Cargo vans (hollow, no sound deadner) have harmonic rings on the driveshafts to absorb some of the gear whine.

 

[JHZR2]

Ok I know what some of you will say, rebuild the diff properly. I did, 7 times, and changed Ring and pinion twice, brand new OEM gearsets. The diff is a IRS mk3 Supra 4.556 ratio , 9 pinion , 41 tooth ring gear.
To cut a long story short, I experimented with various pinion depths and pinion preloads, and found that the diff worked better with a high pinion preload, high end of the acceptable scale of TOYOTA TSRM.
My current iteration of this rebuild, had the pinion run a little shallow for the first 1000km of light break in. Pinion depth shim 1.9mm. The gear pattern looked good but it whined at 60 to 70kmh. I proceed to deepen the pinion depth back to stock shim of 1.94mm. The results are the same. The pinion preload is not low or loose. It is still tight and within spec. But on light throttle at 60 to 70kmh, the whining is at it's loudest. When I let off the throttle, it is virtually silent. I tried various GL-5 Gear oils from Toyota 85W-90, Mobil HD80W90, Mobil HD 80W90 + 25% Lucas Oil Stabilizer, and just recently Lucas Mineral 80W90.
With the lucas, there is 20% reduction in the sound. The Lucas 80W90 seem to not thin as much as the Toyota 85W90 and Mobil HD80W90.
I am looking for a 50% reduction of this whine on light throttle at 60 to 70kmh. To be clear, there is still a whine over 70kmh but the faster I go the fainter the sound gets.
I was thinking of trying a few oils.
1. Lucas Synthethic 75W-140
2.Shell Spirax 85W-140
3. Using Plain old 80W90 + Motorcraft XL-3 additive, some people have said it reduced the ring and pinion noise
View attachment 213914
I want to try to avoid using 140 weight diff oil if possible, as I think it would be like driving the car with another 70kg me in the passenger seat.
I know most of you will say diff oil wont make a difference, but a lot of people sweared by Specialty Formulations GL-5 oil which is now unavailable.
Let me know what worked for you.
Oh yes, Amsoil severe gear 75W110 did nothing on 2 previous rebuilds.

Very valid post.


I agree, just saying rebuild the diff doesn’t always do it.

My 91 318i had a whiny 4.10 LSD when I got it. Had it rebuilt, still noisy. Got another rebuild from a very well known BMW specialist, still was noisy. Tried the different lube viscosities, even tried lucas stuff in there. Never helped with the 60+ mph whine.

The thing that did the trick was Specialty Formulations Racing Gear Lube. Perhaps @MolaKule can explain why… it was a marked difference and I never needed to find another lube for the 100k or so miles that I had the car after that.

Unfortunately SF no longer sells lubricants. And redline and the others didn’t do it (granted I didn’t try shockproof).

 

[cb_13]

Have you tried a banana peel? (Yes it works, no don’t actually do it)

 

[userfriendly]

I'm in the 85W140 camp on this one. A cheap fix if it works.

 

[alcyon]

Very valid post.


I agree, just saying rebuild the diff doesn’t always do it.

My 91 318i had a whiny 4.10 LSD when I got it. Had it rebuilt, still noisy. Got another rebuild from a very well known BMW specialist, still was noisy. Tried the different lube viscosities, even tried lucas stuff in there. Never helped with the 60+ mph whine.

The thing that did the trick was Specialty Formulations Racing Gear Lube. Perhaps @MolaKule can explain why… it was a marked difference and I never needed to find another lube for the 100k or so miles that I had the car after that.

Unfortunately SF no longer sells lubricants. And redline and the others didn’t do it (granted I didn’t try shockproof).

Exactly. A lot of people swear by Specialty Formulations diff oil and Schaeffer 267. What is their "magic" ingredient ?.
I would buy schaffer but even that is impossible to get on amazon.

 

[ctechbob]

Cryo treatment? Wasn't that supposed to do lots of good things, including noise reduction?

 

[alcyon]

Cryo treatment? Wasn't that supposed to do lots of good things, including noise reduction?

I live in a third world country. No one does it here.

 

[Infomercial]

If your country is tropical climate you should try heavier weight.

Mine is and I use redline shockproof heavy and Bar's Leaks 1816 gear repair. The later has reviews claiming it stopped whine.

 

[ripcord]

You don't need different gear oil, you need a louder stereo. Maybe a louder muffler, too.

 

[Rob_Roy]

Swepco 201 90w would be my choice.

 

[dnewton3]

If you have rebuilt a diff 7 times (SEVEN !) and not got rid of the concern, then there is one of two things wrong:
- the gearset is not machined properly; you need to get a different set
- the housing diff has not been machined properly; get rid of that axle and get a different one
No lube is going to fix these issues.

 

[pcoxe]

You don't need different gear oil, you need a louder stereo. Maybe a louder muffler, too.

I think that is the main reason manufacturers started putting better sound systems in cars!

 

[ka9mnx]

75w-140. It's in everything I own.

 

[bonjo]

I was told red line gear products are good for reducing gear whine.

 

[alcyon]

If you have rebuilt a diff 7 times (SEVEN !) and not got rid of the concern, then there is one of two things wrong:
- the gearset is not machined properly; you need to get a different set
- the housing diff has not been machined properly; get rid of that axle and get a different one
No lube is going to fix these issues.

I am still going to try different oils. Like I said it only whines at a certain speed range, its not very loud, its just noticable. I am tired. I also bought a used diff from japan, that was untouched. It has all the original settings, original gearset, pinion shims, carrier bearing shims. I cleaned it out and it was doing almost the same thing, plus an additional whine at 35 to 40kmh. But it was very smooth. I checked the bearings and it looked great, yet there is whine. I did swap the pinion bearings for a new set, and re used the carrier bearings as they looked good. I have not retested that diff yet. But I still have a few more oil combinations to test. I am thinking of mixing a majority of 75W140 or 95W-140 with some 80W90 to bring the spec to about 80W-110 . Right now I have lucas 80W90 with some Liqui moly additive just added. I am gonna run it in a few full tanks of gas and see if the liqui moly helps. I will keep this thread updated if I find a combo that works.