2018 GEM E4 Noise

I concur,

As for the oil, all eM1400s, which use the modern / current setup with AC motors, have a 17:1 TRIM gearbox which uses 80W/90 GL5. The TRIM gearbox can be found in some of the other modern GEMs, but not all, and years of use vary. GEM has three different geraboxes now that I know of; TRIM, Dana and Schafer. Varies by vehicle and/or year, possibly even by which motor the vehicle is ordered with. Other gearboxes might use different oil, although I suspect they all use the same 80/90 GL5 now.

That’s kind of like putting a slice of pizza between two slices of bread and calling it a sandwich,


If lightweight motor oil was in there it will make more noise than 90wt gear oil. Even/especially on backlash.“
Your correct
I guess what I meant to say is Gear Oil has nothing to do with particular problem.

Will a thicker gear oil make the transmission more quite “ absolutely“ 100% but IMO the noise we are hearing is the splines on a motor or input shaft or possibly CV joints. Making noise. And my 2c is Un fortunately thicker gear oil ain’t gonna fix that.in fact Gear oil never even touches or comes in contact with the motor or input shaft. But with that said why not
Gear oil is cheep and replacing it is a whole lot cheaper than anything else so fingers crossed it helps. I would be happy to admit I was wrong it it works! Good luck

Cool. Thanks for the ride.
This is alot more clear as to what you are talking about.
I’m hearing alot of backlash associated with decel and bouncing off the differences of speeds of the motor momentum and the gears catching back up and giving it a hit again.

There are a couple of times I hear the motor shaft doing a bit of vibration or that is when you are pulling on the Jake Brake.

If there was a bunch of regen programmed in then there would be more tension on the set and it wouldn’t be constantly slapping back and forth on the teeth. It would be more about slowing down the car.

I don’t know what triggers the regen on the late cars. Is it a throttle switch, or just throttle position?

Have you tried an oil change yet?
Did I read somewhere they put straight cut gears in the late transmissions?

This might also be a normal sound and you might be a candidate for a quiet kit on that mounting bracket.

Thanks 4 watching,

Its weird the sound removes when accelerating or braking, you can feel it in the pedals.

I’m going to try the oil change w recommended oil once i get some jack stands… stay tuned!

I assume this is just throttle off coasting.
Does it do any different if you press the brake just a tiny bit?
Can you tell if Regen kicks in?

Sounds like what I said

My guess is Input shaft worn and needs new one.

Correct , coasting. Either gas or brake eliminates the issue being heard

Well that’s a classic Input shaft symptom

Thanks Grant , I appreciate your insight

Raised my GEM yesterday and placed on jack stands, accelerated while lifted hearing noted issues mainly from trans and shaft as most thought.

Transmission fluid checked good and topped off.

Thanks for assisting and comments everyone

Michael

So I would think the next step would be to take the motor out and inspect the shaft. You may want to see what the wait time is on a new input shaft & Bering. Also check with Dave fingers crossed that you don’t need a new motor. The Female section of the motor is usually harder material so Normally the cheaper input shaft takes a beating. But in rare cases the motor input is messed up as well. If that’s the case you could throw in the new shaft and just roll with it. It will not be a forever fix. Both input shaft and motor need to be a correct fit other wise it will create slop and you will be back in the same place in no time soon

Thanks GW, there’s a new authorized dealer close to me in Huntington Beach I was going to price and order if available

I just find it crazy that you wore out a main shaft in four years.
Must have not been properly lubed.

Did you post your mileage above? I quick scanned and might have flown over it.

I bought it used from a beach resort in Florida. My guess it was a convenience car for guests and somebody trashed it somehow