Reduce gear noise with single mass flywheel

[R8TID R]

Great! Let us know what you find.



To answer your question, yes the chatter dies indeed stop once the clutch is engaged. The chatter doesn't really bother me. Also you shouldn't be holding the clutch in for extended periods of time.



The noises that bother me are under hard acceleration when the engine is below 2500RPM. it sounds almost like a diesel car. The downside of the polyurethane mounts is they transmit those noises into the cabin pretty well. Rubber mounts really help to isolate those noises.

Very true, the harder polyurethane bushing definitely transmit more vibration and noise to the cabin. My track car is like driving a steel box with concrete wheels compared to my daily driver. It’s tough to strike that perfect balance on a daily driver when you are trying to extract near-maximum performance. I’ll reply shortly about the Redline fluid performance.


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[ATR]

Cool! I'll have to pick some up soon and let everyone here know how it works out

So I've been running Motul Gear 300 75w-90 for the past couple of months. So far here's what I've found...
Cold startup the gearbox is stock quiet. Gear rollover noises are also minimal.

Once it's warmed up it gets a bit rattly. But doesn't seems quite as bad as stock.

If I turn the car off after driving for a bit then come back and drive it again after sitting for 30-45 minutes the gearbox is definitely pretty noisy. As bad as the stock fluid was. I'm almost positive that this is because the engine heat soaks into the transmission and heats the gear oil up enough to thin it out enough that the gears then don't have the same amount of damping they have when fluid is cool.

On the upside, shifting once the transmission is warm and also heatsoaked is much smoother than stock fluid. It would seem that the only downside is when it's colder outside. Below 45°F shifting is notchy until the transmission is warmed up. Which doesn't take long. I'm still holding out until winter to see how it feels.

My opinion is that this is good transmission fluid. But it still leaves a bit to be desired for the gear rollover noise reduction when the transmission is warmed up.

 

[Sumfuncomet]

Clutch/flywheel noise

Do you have upgraded engine mounts though?

I have factory mounts except for APR pendulum mount and 034 upper and lower dogbone

 

[ATR]

I have factory mounts except for APR pendulum mount and 034 upper and lower dogbone

Ahhh, that would explain why you're not hearing what I am. The polyurethane mounts can really allow alot of sounds both from the gearbox and engine to be transmitted through the mounts. MUCH more then the soft OEM mounts. Again the engine and transmission mounts are the ones that really allow you to hear much more of what's going on in the engine bay.

 

[Rigle]

So I've been running Motul Gear 300 75w-90 for the past couple of months. So far here's what I've found...
Cold startup the gearbox is stock quiet. Gear rollover noises are also minimal.

Once it's warmed up it gets a bit rattly. But doesn't seems quite as bad as stock.

If I turn the car off after driving for a bit then come back and drive it again after sitting for 30-45 minutes the gearbox is definitely pretty noisy. As bad as the stock fluid was. I'm almost positive that this is because the engine heat soaks into the transmission and heats the gear oil up enough to thin it out enough that the gears then don't have the same amount of damping they have when fluid is cool.

On the upside, shifting once the transmission is warm and also heatsoaked is much smoother than stock fluid. It would seem that the only downside is when it's colder outside. Below 45°F shifting is notchy until the transmission is warmed up. Which doesn't take long. I'm still holding out until winter to see how it feels.

My opinion is that this is good transmission fluid. But it still leaves a bit to be desired for the gear rollover noise reduction when the transmission is warmed up.

So how has this been in the winter? Too hard to shift?

 

[ATR]

So how has this been in the winter? Too hard to shift?

Thanks for reminding me about this thread!

So I added some of this to the tans fluid around September:
https://www.amazon.com/Liqui-Moly-2019-Anti-Friction-Lubricant/dp/B00CPL8UPY
This seemed to help quiet the transmission down under light load. The kinda noises that sound like bearings.

As for cold shifting. I'm not sure if it's a combo of the MoS2 or what, but even when it was colder out say in the 20's (F) -7C for row it was fine. Up shifting seems like it's always smooth. Downshifting can be a tad hard at times when everything is super cold. However, once I'm on the highway, about 1-2 miles from my house, everything is butter smooth

I think the key is to wake the car up slowly... That is, to drive it casually until it's fully up to temp. I haven't tried to shift it fast when it's cold because we all know that going full send on a cold engine is not good for anything under the hood.

 

[Rigle]

Thanks for reminding me about this thread!

So I added some of this to the tans fluid around September:
https://www.amazon.com/Liqui-Moly-2019-Anti-Friction-Lubricant/dp/B00CPL8UPY
This seemed to help quiet the transmission down under light load. The kinda noises that sound like bearings.

As for cold shifting. I'm not sure if it's a combo of the MoS2 or what, but even when it was colder out say in the 20's (F) -7C for row it was fine. Up shifting seems like it's always smooth. Downshifting can be a tad hard at times when everything is super cold. However, once I'm on the highway, about 1-2 miles from my house, everything is butter smooth

I think the key is to wake the car up slowly... That is, to drive it casually until it's fully up to temp. I haven't tried to shift it fast when it's cold because we all know that going full send on a cold engine is not good for anything under the hood.

Nice. I'm getting quite a bit of chatter at idle so I may try this and see if it helps. When its cold its already hard to down shift with the oem fluid so as long as this doesnt make it worse I'll be happy.

 

[OBP]

https://www.amazon.com/Genuine-Ford-XT-M5-QS-Synthetic-Transmission/dp/B000NUES82
I’ve been running this and have had no cold temp shifting issues. At operating temp, it’s slightly thicker than the Motul fluid, so it has similar noise reduction qualities.

 

[nonegiven]

Nice. I'm getting quite a bit of chatter at idle so I may try this and see if it helps. When its cold its already hard to down shift with the oem fluid so as long as this doesnt make it worse I'll be happy.

Then try to find the oil with the highest VI so it won't be as difficult to shift when cold but will still have a thicker fluid film when hot.

 

[Stija]

Its the smf causing the chatter “at idle.” No amount of VI will help w that.

Is it “chattering” less or not at all with clutch in when stopped and idling?

 

[nonegiven]

Its the smf causing the chatter “at idle.” No amount of VI will help w that.

Is it “chattering” less or not at all with clutch in when stopped and idling?

You're wrong again. Tribology really isn't your subject, is it?

The SMF doesn't make any noise. The "chatter" is gear lash that's soaked up by the DMF but not by the SMF. That's why thicker gear oil quiets the noise.

 

[Stija]

@nonegiven.. so let me get this straight?

Do i not know how the transmission works and what smf chattering is?

Or do i not know tribology?

Two separate issues that youre conflating to show me your superiority, English language and getting your point across not being your forte.

 

[Rigle]

Its the smf causing the chatter “at idle.” No amount of VI will help w that.

Is it “chattering” less or not at all with clutch in when stopped and idling?

No noise with the pedal pushed down or when I first start driving. It gets louder after the gear oil warms up.

 

[nonegiven]

No noise with the pedal pushed down or when I first start driving. It gets louder after the gear oil warms up.

Exactly why it's due to gear lash and why a high VI gear oil will help. They thin out less at higher temps while staying thinner when cold compared to low VI oils.

 

[Stija]

So @nonegiven advice is literally what was suggested in OP, to try different oil, excellent advice!

Why not tell us which oil exactly makes the noise stop? I bet others would like to know too, especially since it is as simple as just using a “high VI gear oil.”

I love learning simple tricks from smart ppl on car forums. I have similar issues w one of my cars except i dont have any noise once moving and id love to get rid of it. I tried different VI oils but nothing changed but tone (lower vs higher). I must have missed the high VI gear oil you’re talking about.