Gen 2 Quad Motor Shuddering and Clunking at full lock?

[Davethadog]

Just picked up my gen 2 quad motor (which was a replacement for a buyback tri-motor) and it's shuddering at full lock. Has anyone else had this issue?

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[Ilovejunebugs]

I've not felt this in my quad.

 

[Edschwartz1]

What's full lock? My quad is awesome!

 

[Davethadog]

What's full lock? My quad is awesome!

Steering lock.

 

[Nixapatfan]

They all do that usually when the wheels are on loose surface like sand or snow, it's due to the extreme angle wheels need to turn for a reasonable turning radius while still being able to cope with the adjustable height suspension. At lower ride height it is less noticeable.

 

[Davethadog]

They all do that usually when the wheels are on loose surface like sand or snow, it's due to the extreme angle wheels need to turn for a reasonable turning radius while still being able to cope with the adjustable height suspension. At lower ride height it is less noticeable.

This is on pavement. My wife’s r1t does not do this.

 

[stickycheeks]

Assuming this is the same issue that was posted on Reddit today with a video:

I don’t personally know what is causing the issue, but I have felt this issue in a quad before. When turning, the wheels feel like they are skipping.

I test drove a quad that had this same issue. The sales person I worked with had told me this issue was normal for the quad motor. I had also test drove a dual and a tri, which didn’t have this issue. The issue was so severe, that I found it very hard to believe that Rivian had designed this feature into their most expensive offering (and was certainly something I would not buy, it felt broken). Being an auto mechanic in my past life, it felt very similar to a wonky half shaft, but to the extreme. So I pushed back on the answer, and asked if they could send it to the service center, and if they could find me another quad to test drive.

Long story short, the service center had a quad, so I and the sales person were able to verify that quad motors are NOT designed with this clunking feature when turning. The sales person later told me that a tech came and verified that there was something wrong with the quad they had, and it was in for repairs the next time I visited. I ended up purchasing a quad, have a little over 1,000 miles on it to date, and I do not have this issue.

This all took place at the Portland Oregon Bridgeport store and Portland downtown service center. Perhaps you could call and get some answers. This took place about a month ago (early December’25) and they are a small team. I would expect they should be able to give you some answers, however feel free to dm me if you need phone numbers and names.

Good luck!

 

[Nixapatfan]

I was going to delve deeper into steering geometry, camber and ride height and how that plays into this at full lock but carry on don't want to derail this, maybe something might be off on yours.

 

[shrink]

Haven’t noticed it on my Gen 2 Quad R1T but will test it out later

 

[stickycheeks]

Haven’t noticed it on my Gen 2 Quad R1T but will test it out later

There’s really no need to test. If yours felt as bad as the one I tested (and assuming @Davethadog’s feels the same as the one I tested) you would presumingly know already. Just do a u-turn at any speed, on any height setting/drive mode. If it feels broken and the front wheels feel like they lurch and skip, then you have a problem. No car should drive this way, and it was verified with my experience that the Rivian Gen2 Quads should not act this way either….the best analogy I can come up with for the feeling is; imagine if your front tires were shaped like flat sides octagons when you u-turn.

 

[RivianR1TinSFL]

Have had mine for less than a month and nothing like this. No issues here.

 

[emoore]

This is on pavement. My wife’s r1t does not do this.

Happens to my gen 1 quad on pavement sometime. Is your wife's R1T a quad?

 

[Davethadog]

this is my fault for not realizing how different the tires are from the standard 22” sports to the super sports that my quad came with.

The noise I am hearing is the sidewall snapping back into line due to the Ackermann effect. It’s cold here in Denver.

 

[MountainBikeDude]

this is my fault for not realizing how different the tires are from the standard 22” sports to the super sports that my quad came with.

The noise I am hearing is the sidewall snapping back into line due to the Ackermann effect. It’s cold here in Denver.

So probably no issue?

 

[Davethadog]

No, no issue I don’t think aside from nobody warning me about this despite delivering the car in 20 degree weather. I can’t really fault them for not knowing this. Apparently it’s very common in the high performance car world but I come from not there.

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