Has anyone experienced a "clunk" noise while shifting into reverse or just starting the car in park. The car sits out in the cold northeast and in Canada and it makes a very noticable "clunk" noise. The transmission fluid has been changed. There is no evidence of any fluid leaks. When the car has been driven and only sits for no more than about two hours, there is no issue. When it has sat for a while (over night), it makes the noise as described above. This just started to occur. Thanks for any advice.

 

Could be the floating calipers? No clunks here in 79k miles on the 07, but the occasional snap when backing out cold. Had same thing with older Avalon.

Just how bad is that clunk? The brakes 'snap'.

 

There is no reverse in Toyota Hybrid transmissions (the HSD) so this is probably not a transmission issue. Your TCH uses the direct drive electric Motor-Generator that is after the tranny in the drive train to go in reverse. You possibly have some play in the drive train between the MG and the front wheels.

JeffD

 

Thanks for the information. The noise is not bad and is like a stone hitting hard underneath the car. I will continue to monitor and see if there is an issue with the calipers sticking when it is cold out. The information that rules out the CVT is good news. Thanks.

 

I hope you had the transaxle/CVT fluid changed at a toyota dealer, using the fluid designed for this particular transaxle. Not only does it contain the power split device, but a drive chain along with MG1 and MG2 which are the generators/electric motors.

I spoke to our local toyota tech. He said he had never replaced any hybrid fluid yet. He said, two local Prius's here in town have around 250,000 miles each, and are running the original transaxle fluid with no problems. One would think it would be good to replace it, but is probably costly.

 

Thanks. I had the CVT fluid replaced at about 30K and then recently at the 60K checkup at the dealership. The dealership was contacted about the "clunk" and they recommended keeping an eye on it to see if it continued to occur. It has not recently. Thanks for the responses.

 

My cost to replace fluid was 5 Quarts at $8.00 a quart plus an hour of my time. Use only Toyota World fluid from the dealer.
The fluid that came out of mine at 28K definitely contained quite a bit of suspended debris and was darker compared to the new fluid. This is cheap insurance for a very expensive unit.

I don't intend to hurt anyone's feelings but stories of people that never perform maintenance are absurd.

 

^^ The prius guys have done the fluid analysis, at 60 it shows a lot of unwanted stuff, silicates from the assemble, high metals from initial grinding.. their recommendation is 30k on the initial then every 60 k.. im at 103K on a just-bought TCH and sending it to Blackstone for analysis next week sometime

 

fastfroward, have a question to you, hopefully, you are still tracking this thread. what exactly is your average mpg in cold Canada? very curious. also, when and if you respond, please, let me know if you reset your average mpg results after refills.
thank you.

 

I have heard that noise, just a few times. I think it is the parking 'dog'.

When you put the shifter lever in 'park', a 'dog' is engaged with one of the gears to prevent the car from rolling while it is turned off. A 'dog' is basically a sliding part that engages the gear, and is pushed in or retracted like a dead-bolt door lock. When you move the shifter out of park, after starting the car, that 'dog' is retracted. Depending on how the car was parked (facing uphill or downhill), and whether the brakes are engaged, retracting the dog might take some force, and might make some noise.