Clicking Sound on Regen Braking

Just got my car back yesterday after leaving it overnight. They replaced the left front axle and the clicking noise is gone!

I have not thoroughly looked over the repairs yet, but it seems like my local dealer in Easley did a good job. I also know that the axle insertion point is higher than the transmission fill point, so transaxle fluid loss would have been minimal.

For anyone interested this is how you change the axle on a gen 3. The process is much the same on the gen 4.

 

Thanks for sharing the video. It’s interesting to note the differences from the Repair Manual (more info) procedures, for both third- and fourth-generation cars, which say to drain the hybrid transaxle fluid completely, to disconnect more of the steering gear, to use special service tools to extract the front drive shaft assembly from the transaxle, and to replace the drive shaft hole snap ring and axle shaft nut with new ones.

 

Interesting. So assuming the dealership follows the repair manual verbatim(I could imagine quite frequently they take shortcuts) you essentially get a free transaxle fluid change.

Unfortunately I just changed my transaxle fluid not three months ago myself... this is what happened when I tried to get the same dealer to change it on my last Prius... Dealership transaxle fluid change nightmare | PriusChat

Hopefully they’ve learned how to properly do it since then. I imagine if they were following the repair manual to see that it was necessary that they clicked the link to see the proper capacity and fill hole for the transaxle this time...

 

Hmm, I started a similar sound at 27K miles it only happens when I drive the car after it has been sitting cold for a few hours. It only happens between 15-35mph while I am using the regenerative breaking to a smooth stop. It does seem like it happens after I make a right turn, wonder if it is the right axle. I think I may let it go for a bit to see if I can pinpoint the location before I bring it in to check, I've never done a warranty repair on my car and am not sure what they will charge me to inspect it..

 

If it makes the noise more when turning right, it's the left axle, and vice versa. If it doesn't make the noise while in neutral, it is almost assuredly the same issue as this thread. Inner CV joint.

 

Yep its the axle. It might be bs, but the dealership is going to replace mine in late January after the part is supposedly redesigned. To diagnose, specialists were flown out to spend a few days on location with my car. The repair ticket is opened and i have received two updates from the dealership that late January is still the plan. 16k miles on my car.

 

Hello. Did they given any other info on this redesign. I had mine replaced in october and they said it was the only one left in the country. Makes me think mine will go out again im at 25k

Posted via the PriusChat mobile app.

 

That aligns with the theory of redesign... if you think about it how could there possibly be one axle in the whole country unless something like this was happening. That being said, they plan on replacing my left axle only. When i asked about the right side they said only if the problem is detected.

Needless to say they are not going to do a mass recall on the thousands upon thousands of cars out there and hope most make it until after they are no longer under warranty (this will become very profitable at that point not that this was intentional) .... so its really important to keep an ear out for this problem no matter how much of a pain in the nice person it is to try to reproduce.

No part number was provided.

 

It could not have been the only one left in the country at that time due to a redesign, I had mine replaced November 4th. It took only 3 days for them to get the part to the dealership.

Why a dealership would lie about that, I don't know. They like to lie and make you feel "lucky" though.

EDIT; One other thing to note, this has plagued Priuses since at least 2005. Ratcheting clank from front left at 8-13 mph slow regen and slight turn right | PriusChat is an example of a Gen 2 doing it, same problem, inner CV joint, only makes noise during Regen braking, goes away in neutral.

Even so most don't do it. Due to the Regen braking, the Prius places far far more stress on the inner CV joint than just about any other car on the road.

 

I knew it was BS when they siad it lol. Did they tell you whats different in the redesign? I had to go through allot to get them to change it. They acted like i was the only person in Cincinnati that had this issue. And they had never seen or heard of this before

Posted via the PriusChat mobile app.

 

I am in cincinnati, they flew in two specialists to spend a few days with the car to diagnose.

 

They also acted like they haven't heard of it before, and I believe them. My area doesn't exactly have a lot of Priuses on the road, it's pretty rural, and Toyota has no TSB out about the axle meaning that unless the dealer had personally seen one he would have no idea about it.(If it was very widespread, there would be a TSB)

I showed them this thread and a video I made of the noise. They still acted like they couldn't hear it, so I demanded a test drive. I took it to a parking lot and rode next to the building so it would echo off. Then they couldn't deny hearing it. I switched it to neutral, so the noise would instantly stop, so they would know it wasn't a brake issue. The first dealer I went to did replace it within a few days, I just had to be prepared with a ton of information.

I am still doubting a redesign of a part that requires as much safety testing as an axle this fast. I am pretty sure the issue is just that Toyota uses thin grease in the axle for efficiency and that there are cases when not enough is put into the inner cv joint. On this thread there is only one person who said he had the issue came back after replacing the axle, and everybody else said it never came back. I also know it existed since Gen 2, and my previous Priuses never exhibited the problem, and I listen every time a Prius drives by and I haven't heard any other one exhibit the issue. I believe this occurs to something like 1 in 1000 Priuses(Random guess based on how often I've seen it on this forum where people are likely to pay attention to such issues more than the average person).

Anybody who has this issue ask their dealer about a redesign. If one could get the information then any dealer could too. I just doubt a redesign would be coming for something this important without even a TSB. Especially since I got one in November from a dealer who talked to Toyota experts that were flown in and then within 2 weeks now there is a redesign coming in just two months. If anything I'd imagine there might be tighter factory controls or something.

 

On December 13, Toyota issued Service Bulletin T-SB-0157-18, “Click Noise From LF Wheel Area During Deceleration,” applicable to 2016–2019 model year Prius cars sold in the U.S. that “exhibit a click noise from the LF wheel area upon deceleration and/or braking.”

The countermeasure is to replace the LH Front Drive Shaft Assembly, original part number 43420-47040, with a new one, part number 43420-47050. Dealers are allowed 1.7 hours of labor to make the replacement, which is done according to procedures already published in the Repair Manual (more info) under Drivetrain: Drive Shaft/Propeller Shaft: Front Drive Shaft Assembly. In the U.S., the repair is covered by the Toyota Powertrain Warranty (60 months or 60,000 miles), but only if the symptom described in the bulletin is present.

At this writing, the bulletin appears to be available only by subscription to techinfo.toyota.com; I’m not aware of a free source.

[Moderator's Note]
This information has been added to the list of all known TSPs for the Prime. Thanks, Elektoingenieur for posting this.
All Known Prius Prime Toyota Service Bulletins (TSBs) | PriusChat

[Moderator's Note #2]
This TSB has been withdrawn. See post: Clicking Sound on Regen Braking | Page 12 | PriusChat

 

man, this car sure has a lot of tsb's

 

Totally new body style. At least they are correcting the issues.

Would you prefer they were covered up like the GM ignition switch issues?

 

no, would prefer there were less, like my '04, '08 and '12

 

Were they totally new chassis designs requiring major factory rework and new part designs?

 

2004, and 2012 pip was somewhat

 

hmmm looks like a redesigned part number to me. Guess the dealership was not BSing me after all.

 

Ahh man.... if this TSB had come out just 1-2 month earlier it would have made my life so so much easier... though I suppose “trailblazers” like us are what make them recognize and release these TSBs.

I’d like to see a comparison. A new part number doesn’t mean too much necessarily. I still suspect different lubricant or amounts or application methods. Especially since it is only left front.