Correlation between motor temps and steering pull issues

[alisdair1941]

Question for those of you who have an issue with a pull to the right. Now that we have the new UI for drive modes, have any of you paid any attention to the motor temps? I had my R1T in to get the steering/alignment done the day before I got the new update and I'm happy to say that they got it to 99% sorted! BUT, there still appears to be a very subtle pull to the right at highway speeds - basically anything over 60mph/100kmph.

Out of curiosity I had a look at the motor temps and I noticed that the front-right motor was always almost 5c above the rest of the motors. All tires are at matching pressure, but that one motor is always running hotter. This has me thinking that it might be running harder due to a higher resistance (maybe a bearing?), which would definitely cause the drive system to counteract it in some capacity, translating to a possible right-pull bias.

Next time you are driving at highway speeds for a length of time and notice a pull to the right/left, check the motor temps. I'm curious what others are seeing.

Or maybe I'm just out to lunch here.

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[240vPlug]

My truck had an alignment issue. SC visit in July got it sorted perfectly I am happy to say. My front motors have a little variation as well. Now it looks like your temps displayed in C. Left shows approximately 118° F and right 129° F so about 11 degrees hotter. Mine normally don't vary by that much. Is it possible sure, but if the motor has an issue i would expect it to run a lot hotter.

Is there any vibration along with the pull? Any abnormal tire wear? These trucks are heavy and i have found the truck will really lean or want to go a different direction when the road is tilted slightly or with variation in the road crowning.

They should be able to provide you before and after alignment specs if your concerned about that. I can't answer 100% on the motor though. My variation has only been at most 5-6° F.

Keep in mind most of the time the front motors are doing more work both under acceleration and regen.

 

[Ecupip]

I noticed the same this week. The front right is always warmer than the others. I don’t have any pull or alignment issues though.

 

[R1Tom]

I see some variation too. Could just be sensor variation or they may not be in thermally equivalent spots on each side.

 

[Rainman]

I have a slight pull to the right after two alignments and also run 3-5 degrees f hotter on the front tight motor.

 

[Zoidz]

While it's possible that there is some connection between the temperature and the pulling, it's unlikely. It's more likely due to a slightly different cooling properties, such as routing and valving of the coolant lines.

"Correlation does not imply causation".

 

[usofrob]

It seems just as likely that Rivian is running that motor more to compensate for the crown in the road to make your car go more straight than it otherwise would.

If you can find a road where the road tilts left for a long time (probably the left lane on a divided road), then you could see if it switches.

 

[240vPlug]

It seems just as likely that Rivian is running that motor more to compensate for the crown in the road to make your car go more straight than it otherwise would.

If you can find a road where the road tilts left for a long time (probably the left lane on a divided road), then you could see if it switches.

I was thinking along similar lines... Maybe to counter torque steer?

 

[R.I.P.]

Curious data point... Anybody running a DM having these pull issues?

 

[R1Tom]

I have a slight pull to the right after two alignments and also run 3-5 degrees f hotter on the front tight motor.

Same as me. Always about that much higher and the classic Rivian slight pull right.

 

[usofrob]

I was thinking along similar lines... Maybe to counter torque steer?

I don't think it's torque steer, I think it's from the camber of the front wheels just following the downhill path of the road.

Curious data point... Anybody running a DM having these pull issues?

If this is true, you might see more alignment issues with the DM as they wouldn't be able to compensate by running more power in the front right.
But you wouldn't be able to measure the left right motor differences because there's only one motor.

 

[Riviot]

It seems just as likely that Rivian is running that motor more to compensate for the crown in the road to make your car go more straight than it otherwise would.

My thoughts exactly. Could also be why it gets a little squirrelly when you gun it on a crowned road.

 

[240vPlug]

I don't think it's torque steer, I think it's from the camber of the front wheels just following the downhill path of the road.

If this is true, you might see more alignment issues with the DM as they wouldn't be able to compensate by running more power in the front right.
But you wouldn't be able to measure the left right motor differences because there's only one motor.

Could be on to something. Will have to see as more and nore DM units hit the streets.

 

[Kochusan]

My right front motor runs about 5 degrees warmer as well. Interestingly, I have an ever so slight slight bias to the left(!) probably tire variation.

Wondering if it's an opposite issue, a difference in cooling? Perhaps that motor is more shielded in some way and dissipates heat less efficiently? I tried driving on a cross town one way road in the left most lane which strongly crowns to the left and the right front motor still runs about 4 degrees warmer.

 

[R1Thor]

My right front motor runs about 5 degrees warmer as well. Interestingly, I have an ever so slight slight bias to the left(!) probably tire variation.

Wondering if it's an opposite issue, a difference in cooling? Perhaps that motor is more shielded in some way and dissipates heat less efficiently? I tried driving on a cross town one way road in the left most lane which strongly crowns to the left and the right front motor still runs about 4 degrees warmer.

Similar experience. The front right runs warmer.

I agree with where your head's at--I'm not thinking this is because that motor is working harder or experiencing different driving dynamics, especially as this seems to be common.
So, for now, I'm assuming there's a difference in the cooling-loop, or there's some type of characteristic simply changing the thermal parameter to the front right motor. 5 degF is honestly not a huge swing. If we were seeing 15+, I'd be a tad concerned.

FWIW: I *did* have a significant right pulling issues and had Rivian perform an alignment around 1k miles in. I'm at 12k now and have a *slight* occasional pull to the right on certain roads. They did tell me they performed the alignment at multiple ride heights.

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