Clunking sound from front end.

[kyledmb]

Well my R1T went into the Seattle service center this morning. On the ride along, the tech definitely noticed the rattling sound, but things its a loose panel or something. I told him I thought it was half shaft play. He seemed unconvinced. Ugh.

He did mention that he noticed things that will lead to replacing both the front jounce lines and the dampers. I guess we'll see.

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[Jonger1150]

Well my R1T went into the Seattle service center this morning. On the ride along, the tech definitely noticed the rattling sound, but things its a loose panel or something. I told him I thought it was half shaft play. He seemed unconvinced. Ugh.

He did mention that he noticed things that will lead to replacing both the front jounce lines and the dampers. I guess we'll see.

They have no fix for the half-shafts, that's why he basically changed the subject. The half-shafts are the primary issue with noise on this vehicle. Update us when you get it back.

 

[kyledmb]

will do. They acknowledged the sound, so they can say they think its whatever they think it is. If they return it to me and its not fixed, its an immediate ticket and call to support. The sound is problematic enough that anyone who drives it will hear it and be alarmed. So very easy for them to see if whatever remedy they implement worked.

 

[Deezel]

I assume the cold temps result in the grease becoming more viscous and thus dampens the axle spline movements resulting in less noise. It would seem they should be able to come up with a way to permanently dampen this movement regardless of temp.

Don't you mean less viscous? ie thicker? Cold temps generally make liquids and greases thicker.

I could see how that could dampen some of the noise..

 

[R1Tom]

Don't you mean less viscous? ie thicker? Cold temps generally make liquids and greases thicker.

I could see how that could dampen some of the noise..

I believe you have that inverted. More viscous is thicker. Less viscous is thinner.

 

[Deezel]

I have not had a chance to read this entire thread, but I think there are two (at least) service bulletins that may be related to the "clunking" noise.

I believe the clunking noise is usually the CV axles having some lateral play.

My theory is this play only reveals itself at low speeds, where the suspension compression/extension forces are higher than the rotational forces of the CV axle spinning. Once the CV axle is rotating fast enough, say at freeway speeds on smooth roads the rotational forces keep the CV centered, or the CV axle/interface get warm enough it takes up the slop. I have yet to hear the clunking noise at speeds over 40mph on my truck, even on imperfect roads.

Has anyone heard "clunking" noises at high speeds?

Like others on the forum here I can actually pull (up and down laterally, not along the axis) on my CV axles and get them to make the exact same noise. It is a small amount of play, but the amount of noise it makes is substantial. This entire truck is so stiff/hollow and devoid of other noises that I think it makes small noises like this more evident.

I don't think it's a major concern, but overtime those small loading events could cause an issue with either the axle itself or the mating parts.

Anyhow, here are the actual TSBs I think most of you are referring to:

The first TSB tightens the hub to the knuckle. Presumably, some vehicles were assembled with insufficient torque. Without seeing the inner parts it's tough to say how this helps, but I can only assume this would provide better engagement with the CV axle splines on the hub/wheel side, OR forces the CV axle farther into the motor side splines, maybe both. In fact, the TSB does say to " Make sure that the halfshaft is properly seated within the knuckle :

Some splines are tapered, or even curved, so the more engagement you get the less lateral (radial) play. Even straight splines should have a reduction in radial play just by engaging more of the splines.

Here is that TSB:

MC-11008362-0001.pdf

The Second TSB accomplishes something similar but appears to use preloaded (bent) washers to help fill in some of the gap that causes lateral play. In fact it appears they apply the washers to the same area of the CV axle that they are tightening the hub/axle nut against.

MC-10240309-0001.pdf

What's odd about the second TSB though is this would seem to reduce the wheel side spline engagement but perhaps increase the motor side engagement. Ulitmately though I think the goal was just to reduce axial play. I'm sure there is probably sufficient margin in the spline engagement for this, but given my options I would chose the first TSB. Luckily the second TSB appears to be only for 2022 or earlier vehicles. Perhaps something was revised in later vehicles OR they realized the washers were just a fix for the hub torque being insufficient.

At the end of the day the fact this vehicle can raise/lower it's suspension geometry as much as it does and still have sufficient spline engagement and not bind up the joints or do other types of destruction is pretty remarkable. I'm sure compromises were made somewhere but I applaud Rivian for pulling this off.

I'm sure they can come up with a long term fix if the torque increase and other TSBs don't solve it.

It may require tighter tolerancing, hopefully on the CV axle side. That would seem to be a much easier swap than a motor/spline/housing swap.

 

[Deezel]

I believe you have that inverted. More viscous is thicker. Less viscous is thinner.

You're right. I read that wrong.

Viscosity is the resistance to shearing/flow so more is thicker!

 

[kyledmb]

I have not had a chance to read this entire thread, but I think there are two (at least) service bulletins that may be related to the "clunking" noise.

I believe the clunking noise is usually the CV axles having some lateral play.

My theory is this play only reveals itself at low speeds, where the suspension compression/extension forces are higher than the rotational forces of the CV axle spinning. Once the CV axle is rotating fast enough, say at freeway speeds on smooth roads the rotational forces keep the CV centered, or the CV axle/interface get warm enough it takes up the slop. I have yet to hear the clunking noise at speeds over 40mph on my truck, even on imperfect roads.

Has anyone heard "clunking" noises at high speeds?

Like others on the forum here I can actually pull (up and down laterally, not along the axis) on my CV axles and get them to make the exact same noise. It is a small amount of play, but the amount of noise it makes is substantial. This entire truck is so stiff/hollow and devoid of other noises that I think it makes small noises like this more evident.

I don't think it's a major concern, but overtime those small loading events could cause an issue with either the axle itself or the mating parts.

Anyhow, here are the actual TSBs I think most of you are referring to:

The first TSB tightens the hub to the knuckle. Presumably, some vehicles were assembled with insufficient torque. Without seeing the inner parts it's tough to say how this helps, but I can only assume this would provide better engagement with the CV axle splines on the hub/wheel side, OR forces the CV axle farther into the motor side splines, maybe both. In fact, the TSB does say to " Make sure that the halfshaft is properly seated within the knuckle :

Some splines are tapered, or even curved, so the more engagement you get the less lateral (radial) play. Even straight splines should have a reduction in radial play just by engaging more of the splines.

Here is that TSB:

MC-11008362-0001.pdf

The Second TSB accomplishes something similar but appears to use preloaded (bent) washers to help fill in some of the gap that causes lateral play. In fact it appears they apply the washers to the same area of the CV axle that they are tightening the hub/axle nut against.

MC-10240309-0001.pdf

What's odd about the second TSB though is this would seem to reduce the wheel side spline engagement but perhaps increase the motor side engagement. Ulitmately though I think the goal was just to reduce axial play. I'm sure there is probably sufficient margin in the spline engagement for this, but given my options I would chose the first TSB. Luckily the second TSB appears to be only for 2022 or earlier vehicles. Perhaps something was revised in later vehicles OR they realized the washers were just a fix for the hub torque being insufficient.

At the end of the day the fact this vehicle can raise/lower it's suspension geometry as much as it does and still have sufficient spline engagement and not bind up the joints or do other types of destruction is pretty remarkable. I'm sure compromises were made somewhere but I applaud Rivian for pulling this off.

I'm sure they can come up with a long term fix if the torque increase and other TSBs don't solve it.

It may require tighter tolerancing, hopefully on the CV axle side. That would seem to be a much easier swap than a motor/spline/housing swap.

I think your theory above in bold is absolutely spot on.

 

[Jonger1150]

Don't you mean less viscous? ie thicker? Cold temps generally make liquids and greases thicker.

I could see how that could dampen some of the noise..

It has been warm here the last two days and the half-shafts have been louder. We should lock in below 60 temps soon and that will quiet things down until May.

 

[Jonger1150]

I have not had a chance to read this entire thread, but I think there are two (at least) service bulletins that may be related to the "clunking" noise.

I believe the clunking noise is usually the CV axles having some lateral play.

My theory is this play only reveals itself at low speeds, where the suspension compression/extension forces are higher than the rotational forces of the CV axle spinning. Once the CV axle is rotating fast enough, say at freeway speeds on smooth roads the rotational forces keep the CV centered, or the CV axle/interface get warm enough it takes up the slop. I have yet to hear the clunking noise at speeds over 40mph on my truck, even on imperfect roads.

Has anyone heard "clunking" noises at high speeds?

Like others on the forum here I can actually pull (up and down laterally, not along the axis) on my CV axles and get them to make the exact same noise. It is a small amount of play, but the amount of noise it makes is substantial. This entire truck is so stiff/hollow and devoid of other noises that I think it makes small noises like this more evident.

I don't think it's a major concern, but overtime those small loading events could cause an issue with either the axle itself or the mating parts.

Anyhow, here are the actual TSBs I think most of you are referring to:

The first TSB tightens the hub to the knuckle. Presumably, some vehicles were assembled with insufficient torque. Without seeing the inner parts it's tough to say how this helps, but I can only assume this would provide better engagement with the CV axle splines on the hub/wheel side, OR forces the CV axle farther into the motor side splines, maybe both. In fact, the TSB does say to " Make sure that the halfshaft is properly seated within the knuckle :

Some splines are tapered, or even curved, so the more engagement you get the less lateral (radial) play. Even straight splines should have a reduction in radial play just by engaging more of the splines.

Here is that TSB:

MC-11008362-0001.pdf

The Second TSB accomplishes something similar but appears to use preloaded (bent) washers to help fill in some of the gap that causes lateral play. In fact it appears they apply the washers to the same area of the CV axle that they are tightening the hub/axle nut against.

MC-10240309-0001.pdf

What's odd about the second TSB though is this would seem to reduce the wheel side spline engagement but perhaps increase the motor side engagement. Ulitmately though I think the goal was just to reduce axial play. I'm sure there is probably sufficient margin in the spline engagement for this, but given my options I would chose the first TSB. Luckily the second TSB appears to be only for 2022 or earlier vehicles. Perhaps something was revised in later vehicles OR they realized the washers were just a fix for the hub torque being insufficient.

At the end of the day the fact this vehicle can raise/lower it's suspension geometry as much as it does and still have sufficient spline engagement and not bind up the joints or do other types of destruction is pretty remarkable. I'm sure compromises were made somewhere but I applaud Rivian for pulling this off.

I'm sure they can come up with a long term fix if the torque increase and other TSBs don't solve it.

It may require tighter tolerancing, hopefully on the CV axle side. That would seem to be a much easier swap than a motor/spline/housing swap.

Jounce lines and Dampers have new parts that solve noise issues, we need a revised half-shaft.

I don't believe half-shafts have changed since launch.

All of my suspension issues are gone about 35 mph. Above those speeds I forget all about them and shift my attention to audio related rattles. LOL

 

[DaveA]

I have not had a chance to read this entire thread, but I think there are two (at least) service bulletins that may be related to the "clunking" noise.

I believe the clunking noise is usually the CV axles having some lateral play.

My theory is this play only reveals itself at low speeds, where the suspension compression/extension forces are higher than the rotational forces of the CV axle spinning. Once the CV axle is rotating fast enough, say at freeway speeds on smooth roads the rotational forces keep the CV centered, or the CV axle/interface get warm enough it takes up the slop. I have yet to hear the clunking noise at speeds over 40mph on my truck, even on imperfect roads.

Has anyone heard "clunking" noises at high speeds?

Like others on the forum here I can actually pull (up and down laterally, not along the axis) on my CV axles and get them to make the exact same noise. It is a small amount of play, but the amount of noise it makes is substantial. This entire truck is so stiff/hollow and devoid of other noises that I think it makes small noises like this more evident.

I don't think it's a major concern, but overtime those small loading events could cause an issue with either the axle itself or the mating parts.

Anyhow, here are the actual TSBs I think most of you are referring to:

The first TSB tightens the hub to the knuckle. Presumably, some vehicles were assembled with insufficient torque. Without seeing the inner parts it's tough to say how this helps, but I can only assume this would provide better engagement with the CV axle splines on the hub/wheel side, OR forces the CV axle farther into the motor side splines, maybe both. In fact, the TSB does say to " Make sure that the halfshaft is properly seated within the knuckle :

Some splines are tapered, or even curved, so the more engagement you get the less lateral (radial) play. Even straight splines should have a reduction in radial play just by engaging more of the splines.

Here is that TSB:

MC-11008362-0001.pdf

The Second TSB accomplishes something similar but appears to use preloaded (bent) washers to help fill in some of the gap that causes lateral play. In fact it appears they apply the washers to the same area of the CV axle that they are tightening the hub/axle nut against.

MC-10240309-0001.pdf

What's odd about the second TSB though is this would seem to reduce the wheel side spline engagement but perhaps increase the motor side engagement. Ulitmately though I think the goal was just to reduce axial play. I'm sure there is probably sufficient margin in the spline engagement for this, but given my options I would chose the first TSB. Luckily the second TSB appears to be only for 2022 or earlier vehicles. Perhaps something was revised in later vehicles OR they realized the washers were just a fix for the hub torque being insufficient.

At the end of the day the fact this vehicle can raise/lower it's suspension geometry as much as it does and still have sufficient spline engagement and not bind up the joints or do other types of destruction is pretty remarkable. I'm sure compromises were made somewhere but I applaud Rivian for pulling this off.

I'm sure they can come up with a long term fix if the torque increase and other TSBs don't solve it.

It may require tighter tolerancing, hopefully on the CV axle side. That would seem to be a much easier swap than a motor/spline/housing swap.

Great explanation. I agree the variability in the ride heights necessitates a small amount of play in the shafts due to various angles etc, but it’s still annoying. I’ve almost come to live with it, but arghhh.

 

[kyledmb]

It has been warm here the last two days and the half-shafts have been louder. We should lock in below 60 temps soon and that will quiet things down until May.

Bummer, I remember you reporting your noises were mostly gone. Warm weather brought them back, eh?

 

[jmtreetop]

I had the jounce line and hub to knuckle fix done today and it made a world of difference. So far no noises or squeaks. I had so many rattles, clunks, chirps, and squeaks before this at low speeds. You still hear tires hitting bumps but it feels and sounds solid where before it felt like it was falling apart.

 

[Jonger1150]

Bummer, I remember you reporting your noises were mostly gone. Warm weather brought them back, eh?

Yup, they're louder above 60F. I'm going to follow the forums and keep an eye on any successful fixes or new part revisions.

The plan is to trade this in if there's no fix by the end of my lease. Hopefully Rivian has this fixed by then. You'll notice most people who list SC issues always have this one on the docket. The noisy half-shafts are a pain in the ass for Rivian customer satisfaction.

 

[Deezel]

Jounce lines and Dampers have new parts that solve noise issues, we need a revised half-shaft.

I don't believe half-shafts have changed since launch.

All of my suspension issues are gone about 35 mph. Above those speeds I forget all about them and shift my attention to audio related rattles. LOL

Right. I do hear some limited squish/squeeling noises on suspension compression, which I'm sure is related to the air suspension, but I'm not sure it's realistic to have an air suspension be completely quiet so I'm willing to tolerate that. It rides/handles great as is.

The potential play in CV axles and metallic clunk is way more of a concern. There has to be a fix for this, it just comes down to tolerancing which I'm not saying is easy, but should be do able.

I know others have had the 'tock' noise issue when stopping/accelerating also. I'd assume that is from spline tolerancing also just in a.. circumferential direction. Meaning, the individual fit of the splines and the motor/hub housing cuts themselves.

I am hoping that the "clunk" noise does not eventually lead to the "tock" noise due to wear..

Does anyone know if there is in fact a new CV axle PN or not? It would be good to confirm.

Maybe RCV or some other well known CV axle manufacture would make some replacements that fit better. No way they would be cheap, but given the power/instant torque of these trucks I would expect them to command a premium.. The OEM CV axles are some of the beefiest I've ever seen.

RCV Performance - Ultimate CV Axles

Luckily we have our warranties for now. When that runs out though maybe aftermarket support is the solution. I can't tell you how many aftermarket parts have fixed annoying issues with my Jeep!

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