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Julian73 suggested Lotus doesn't add any gears to the transmission, but the Lotus Tech and others on this forum have said they DO add one or more gears because the transmission is mounted transversely in the Evora, which was not how the transmission was originally designed and so "extra" gear(s) are required to support this orientation. In addition to that, Lotus does change some number of the normal gears to play with the ratios but those aren't "extras", just swapouts. It is possible these extra gears are the source of the sound, but no matter what it's not a "good" sound which is why it got my attention.
to me when someone states Louts adds gears to the trans, that means it was a 4 or 5 speed trans and lotus did their thaaaaannngggg.... and made it a 6 speed box, which isn’t the case and I think where some of the confusion is,
 

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2020 Evora GT in Formula Red, coordinated black+red interior, windowed engine hatch
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Discussion Starter #62
Maybe try recording the audio so you will have something for the tech to listen to and analyze in the event you can't make it fail during next test drive.
Good idea, though I've had difficulty doing that for driveline sounds on boats in the past. Can't hurt to try, though. Thanks!
 

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I had recorded attempts to locate a horrible vacuum whine and after proper capping and cleaning up of vacuum lines I was able to finally recreate and manipulate the sound. Located broken TB bracket and found they were early model brackets and upgraded all the early REV components to current level. Recording and using db meter has helped me locate sources many times.
 

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to me when someone states Louts adds gears to the trans, that means it was a 4 or 5 speed trans and lotus did their thaaaaannngggg.... and made it a 6 speed box, which isn’t the case and I think where some of the confusion is,
That is my interpretation of "adding"gears, thank you for clarifying. I would Have thought that most people having read past my opening line would understand that I agreed that Lotus changed out gear sets.
 

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I just got back from taking my "second Mom" to lunch for her birthday. She's 85 years old today but was as giddy as a little girl in the Lotus. Her husband passed away a few years ago, and I knew him very well, but being in the Lotus reminded her of a part of his life I had never heard about: When he was young, he was a member of a car club and drove sports cars! All these decades and I had never heard about that. But she got to relive that today and share it with the rest of us at lunch.

Just another day for a Lotus, making people happy and bringing back great memories.
 

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2020 Evora GT
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I specifically asked about helical vs straight cut in the lower gears due to the noise differences Was informed the lower gears are noisier in part because they are cut straighter ( not straight) than the higher gears to better handle the torque.
 

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What engine speeds (RPM) are you guys at when you notice the gear rattle? The only time I hear it in my S is when I'm basically lugging the engine in 1st or 2nd gear. Either creeping up my driveway in 1st, or if I try to pull away from a slow roll in 2nd gear. I have to be below about 1500 rpm. It's really not that loud or bothersome on my S, but maybe it's worse on the 4xx models? At any rate, I wouldn't advise driving around at such low RPMs regularly as it is not particularly good for the bottom end of the engine.

The gear rattle is noticeable because these cars have single mass flywheels and lightweight ones at that. It's normal. I could have sworn there was a note about this in the owner's manual or service notes stating that but I can't seem to find it at the moment. Most modern cars with manual transmissions have dual mass flywheels which filter out the noise and vibrations. If I remember right, the S flywheel is right around 12-13 lbs. For comparison, the dual mass flywheel in an E39 M5 is ~40 lbs.
 

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2020 Evora GT in Formula Red, coordinated black+red interior, windowed engine hatch
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Discussion Starter #69
Without running out to test it again, your description sounds pretty accurate to my experiences so far. I'm not lugging the engine, but it's definitely under 10 MPH. An important detail, to me, is that the sound does NOT occur when the clutch is first engaged... there's a period of quietness before the speed increases a bit and then the growl starts.

I too am no fan of lugging an engine. In fact I often drop the shifter at least one gear to let the engine run around 3000 RPM rather than the more fuel-efficient higher gears that the GSI keeps insisting I use. I get better throttle response, plus I just don't like forcing engines to lug around. They purr when they're happy, which makes me happy.

Next time I take it out I'm going to spend a bunch of time messing around with slow speeds and gear loading/unloading. I'll also try to record the sound and if that works I'll post it here.
 

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Regardless what causes it, the reality is that "they all do that, sir." Unless one whine is different than another by reason of manufacturing fault, it's of no consequence and a symptom for which Lotus does not feel compelled to offer a cure and for which one is not required. I no longer notice it, it's just another of the car's mechanical presences. I'd say most owners have noticed it. Those who like me have had their car for a few years have long forgotten about it in day to day driving. Part of "breaking in" a car is learning about the things we didn't pay attention to when we were besotted with the notion that we wanted it in the first place. This car breaks you in just as much as you do the car and for a first time owner (like me) you eventually realize it is expected to do so by design.

The noises these cars make are generally quite glorious, also can be very mechanical. I'd sooner they gave us oil pressure and temp. gauges than bother to improve the minimally invasive gearbox sounds at this stage of the game b ut a more confidence inspiring (more power capable) transmission would be swell too. But overall, it's somewhat amazing what they did with the Evora given the resources at hand (misquote of Dr. Pittenson) when it was conceived and redesigned for S2 production.

As encouragement, after three years with the brand, I can say that they've treated me fairly. They will you too.
 

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Things that annoy me- exterior temperature garage instead of a useful gay age like oil pressure or temp.
things I don’t even notice: transmission noises.
May 964 had custom gearsets, and whines like a sonofabitch. I honestly don’t hear anything in my evora
 

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2020 Evora GT in Formula Red, coordinated black+red interior, windowed engine hatch
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Discussion Starter #72
Regardless what causes it, the reality is that "they all do that, sir." Unless one whine is different than another by reason of manufacturing fault, it's of no consequence....
To be clear, my only concern is that the noise isn't indicative of a problem. If I can make it happen in front of the Lotus Tech, or record it and have folks here tell me TADTS, I'm totally fine with it.
 

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2020 Evora GT in Formula Red, coordinated black+red interior, windowed engine hatch
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Discussion Starter #73
Things that annoy me- exterior temperature garage instead of a useful gauge like oil pressure or temp.
Amen to that! As said above, all I care about is that this particular sound is "normal". And yes indeed, I would GLADLY trade the exterior temperature display for oil pressure and engine temperature. In my opinion those two are critical data for a high performance engine. Heck, my boat displays them. Even if they were just part of the left-side rotating "info" screens it would be an improvement. It's an ECU based engine, so the sensors are present and the data is already available (and probably on the CAN network in J1939 format). Why omit it when they have two dot matrix LCD screens? {shakes head}
 

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To be clear, my only concern is that the noise isn't indicative of a problem. If I can make it happen in front of the Lotus Tech, or record it and have folks here tell me TADTS, I'm totally fine with it.
I think you will find that its the same as what virtually all of our manual cars sound like. At least, I certainly hope there isn't an issue.

Over the years, there have been a ton of posts about it. In both S1s and S2s. I don't recall anyone ever having a major issue based on the low RPM noise.
 

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Amen to that! As said above, all I care about is that this particular sound is "normal". And yes indeed, I would GLADLY trade the exterior temperature display for oil pressure and engine temperature. In my opinion those two are critical data for a high performance engine. Heck, my boat displays them. Even if they were just part of the left-side rotating "info" screens it would be an improvement. It's an ECU based engine, so the sensors are present and the data is already available (and probably on the CAN network in J1939 format). Why omit it when they have two dot matrix LCD screens? {shakes head}
I agree it was not nice to lose coolant temp, the idiot lights are as follows. blue cold coolant goes off at 70 C, Red excessive temp lights up at 113 C. Temp info is on the CAM bus and can be displayed on OBD2 apps onto a phone, I receive mine on my AIM timer. While the engine does has low oil pressure "switches", it does not have a range pressure transducer, so nothing to pick up on the CAN .. what would be nice is a scroll display of available CAN stuff such as MAP, IAT, Transmission Oil temp. We may just have to wait for the pending release of the Lotus-AIM dash display
 

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2020 Evora GT in Formula Red, coordinated black+red interior, windowed engine hatch
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Discussion Starter #76
While the engine does has low oil pressure "switches", it does not have a range pressure transducer, so nothing to pick up on the CAN
I'm surprised by that. Toyota builds that engine for a variety of applications including their own. I'd expect an oil pressure transducer for their own purposes, which Lotus could then just use.
 

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The gear noise is common in aftermarket gear sets or final drive ratios. It is the result of "straighter" helical gears which are cheaper and easier to manufacture for additional strength. This is simply the result of a tiny auto manufacturer expending only the resources necessary to get the job done without spending a lot more to achieve complete refinement. There is no issue with the transmission. It's just a result of the design and monetary constraints.
 

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I'm surprised by that. Toyota builds that engine for a variety of applications including their own. I'd expect an oil pressure transducer for their own purposes, which Lotus could then just use.
Most cars don't have drivers that care to look at oil pressure, and all the engine really cares about is if it is too low, thus a pressure switch flagging CEL
 

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The gearbox we use is from a European Toyota. We leave in the original 1st and 2nd gear but change out 3,4,5,and 6. The noise in first and second is normal and nothing to be concerned about. Rule of thumb is if the noise stops when the clutch pedal is pressed then it's ok.

Transmission Noise
Gear Rattle is a repetitive metallic impact or rapping noise which occurs on a manual transmission powertrain when the vehicle is lugging in gear. The rattle noise intensity generally increases with transmission operating temperature and engine torque, and decreases with increasing vehicle speed. Since the gear ratios have been designed to achieve maximum fuel economy, there may be instances when gear rattle is distinctly noticeable this, however, is not detrimental to the engine or transmission
NOTE:
Replacement of transmission components will not correct neutral rollover rattles. Neutral Rollover Rattle has the same characteristics as gear rattle except that rollover occurs with the engine idling, transmission in NEUTRAL, and the clutch engaged (clutch pedal released). The rollover noise intensity increases with transmission operating temperature and engine torque load resulting from air conditioning etc.
Neutral rollover noise is not detrimental to the engine or transmission. In some cases a harsh clattering noise like loose marbles in the transmission may
be heard. Rollover Noise caused by engine torsional vibrations and Clutch Release Bearing Noise are sometimes mistaken for Transmission Bearing Noise. Transmission service will not eliminate gear rollover noise.
Gear rollover noise, inherent in manual transmissions, is caused by the constant mesh gears turning at engine idle speed, while the clutch is engaged and the transmission is in NEUTRAL, gear rollover noise will disappear when the clutch is disengaged or when the transmission is engaged in gear.
 

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2020 Evora GT in Formula Red, coordinated black+red interior, windowed engine hatch
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Discussion Starter #80
Thank you for that "Transmission Noise" excerpt. I'll have the Lotus Tech listen next time it's at the shop, but I'm pretty much convinced it's normal and nothing to worry about. I've driven the Evora GT several times in the last 24 hours and I can make the noise occur at will now, based on modulating the throttle vs. the load on the transmission. Everything behaves how the excerpt describes.

I am thankful I don't have the "marbles in the transmission" sound. That would be quite nasty.
 
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