jcdwrd

I have a 07 Ls460. When downshifting from second to first there is a click that is sometimes a clunk. Lexus has replaced the trans with no change. They have cleaned and lubricated rear suspension bolts and replaced the rear shocks and springs and the differential mount. Again, no change. This started at about 80k and continues at 123k. They have checked motor mounts, transmission mount and repacked the driveshaft spline. When the car is lifted into the air and the weight is off the suspension the noise will go away for a few days.
This noise has also been heard occasionally when rolling off the gas between 20/30 mph and then reapplying throttle.
Lexus mechanics and area reps are at a loss to diagnos.
I have driven a 2008 loaner and it had the same noise.
Has anyone else run into this problem and does anyone know of a cure?

Lavrishevo

iTrader: (1)

In my experience, when you are getting a hard shift from 2nd into 1st you are low on transmission fluid. I would have them double check the fluid level and make sure the transmission is heated to the proper temp and they shift through the gears and then recheck the fluid level. It's in the Lexus service manual. If you do not heat the transmission properly it can cause you to under-fill the unit. It won't allow for the proper amount of fluid needed. The 04-06 430 and 07+ "sealed" transmissions are complicated units. They need to be loved when they are serviced.

jcdwrd

The ATF was checked and later changed in the original trans. It was also checked after changing. It also had a computer update that seemed to make it a bit harsher downshift. The second trans behaves the same as the first and fluid level has been checked. All work is performed at a Lexus dealership.

caha14

My '08 460L had some hard-to-troubleshoot vibrations, steering and driveline, when I got it. In addition, it also occasionally exhibited this clunk you described.

The one thing they did to my previous LS that is not on your list is replace the driveshaft. This fixed the driveline vibration, AND the clunk also went away. I get that they repacked the splines on yours, but to the extent that there is any excessive play that they haven't caught, repacking won't solve the problem, so my vote is on the driveshaft (if you are able to convince them to try).

Lavrishevo

iTrader: (1)

I would just double check and make sure the dealer heats the transmission to whatever the proper temp is. Like 120 degrees and check again. Most DO NOT do this procedure. They skip it and the trans is can easily be under-filled. They should hook up their computer and it tells them when it's the proper temp. I know that sounds odd but it has helped others fix very similar problems. If you check the fluid after the car has cooled down a bit it will seem ok but it is really low on fluid. Does not take much for it to shift hard when low. Dealers make this mistake all the time. It's an easy procedure for the dealer just make sure it is at the proper temp when they check the level. It's all about being at operating temperature then pump fluid in the overflow port until it overflows.


This is for the 04+ 430 but the procedure is essentially the same. So you can have some technical info.


AUTOMATIC TRANSMISSION FLUID ADJUSTMENT

1. BEFORE TRANSMISSION FILL
_ This transmission requires Toyota Genuine ATF WS.
_ It is necessary to refill the transmission with the correct
amount of fluid.
_ The vehicle must remain level while adjusting fluid level.

2. TRANSMISSION PAN FILL
(a) Remove the two bolts and transmission case cover.
(b) Remove the refill plug and overflow plug.
(c) Fill the transmission through the refill hole until fluid begins
to trickle out of the overflow tube.
(d) Reinstall the overflow plug.

3. TRANSMISSION FILL
(a) Fill the transmission with the correct amount of fluid as
listed in the table below.
(b) Reinstall the refill plug to avoid fluid splash.
Performed Repair Fill Amount
Transmission pan and drain plug removal
1.3 liters (1.37 US qts, 1.14 Imp. qts)
Transmission valve body removal 3.9 liters (4.12 US qts, 3.43 Imp. qts)
Torque converter removal 5.3 liters (5.60 US qts, 4.66 Imp. qts)
Entire transmission assembly 5.3 liters (5.60 US qts, 4.66 Imp. qts)
HINT:
If you cannot add the listed amount of fluid, do the following:
(1) Install the refill plug.
(2) Allow the engine to idle with air conditioning OFF.
(3) Move the shift lever through entire gear range to circulate
fluid.
(4) Wait for 30 seconds with the engine idling.
(5) Stop the engine.
(6) Remove the refill plug and add fluid.
(7) Reinstall the refill plug.

4. FLUID CIRCULATION
(a) Allow the engine to idle with the air conditioning OFF.
(b) Move the shift lever through entire gear range to circulate
the fluid.

5. FLUID TEMPERATURE CHECK
NOTICE:
_ On vehicles equipped with air suspension, perform
step (c) if it necessary to jack up the vehicle while the
engine running.
_ The fluid temperature should be less than 30_C (86_F)
before beginning the fluid temperature check.
(a) With hand-held tester
(1) Connect the hand-held tester to the DLC3.
(2) Select the tester menus: OBD/MOBD, ENGINE,
DATA LIST and A/T.
(3) Check A/T OIL TEMP.
(4) Allow the engine to idle until the fluid temperature
reaches 46_C (115_F).
(b) Without hand-held tester (Using D shift indicator)
(1) Connect terminals between CG (4) and TC (13) of
the DLC3 using SST (09843-18040).
(2) Move the shift lever back and forth between N and
D every 1.5 seconds for six seconds.
(3) The D shift indicator on the combination meter
comes on for two seconds. This indicates that the
fluid temperature check mode has been started.
(4) The D shift indicator will come on again when the
fluid temperature reaches 46_C (115_F) and will
blink when it exceeds 56_C (130_F).
(5) Allow the engine to idle unit the fluid temperature
reaches 46_C (115_F).
(c) For vehicles with air suspension (Using D shift indicator)
(1) Connect terminals between CG (4), OPA (11) and
TC (13) of the DLC3 using SST (09843-18040).
Terminal OPA is connected to prevent air suspension
height adjustment from occurring when the vehicle
is lifted off the ground with the engine running.
(2) Move the shift lever back and forth between N and
D at 1.5 seconds interval for six seconds.
(3) The D shift indicator on the combination meter
comes on for two seconds. This indicates that the
fluid temperature check mode has been started.
(4) The D shift indicator comes on again when the fluid
temperature reaches 46_C (115_F) and will blink
when it exceeds 56_C (130_F).
(5) Allow the engine to idle until the fluid temperature
reaches 46_C (115_F).

6. FLUID LEVEL CHECK
NOTICE:
The fluid temperature must be between 46_C (115_F) and
56_C (130_F) to accurately check the fluid level.
(a) Remove the overflow plug with the engine idling.
(b) Check that the fluid comes out of the overflow tube.
_ If fluid does not come out, proceed to step 7
_ If fluid comes out, wait until the over-flow slows to
a trickle and proceed to step 8.

7. TRANSMISSION REFILL
(a) Install the overflow plug.
(b) Stop the engine.
(c) Remove the refill plug.
(d) Add 0.4 liters (0.42 US qts, 0.35 Imp. qts) of fluid.
(e) Allow the engine to idle and wait for 10 seconds.
(f) Proceed to step 6.

8. COMPLETE
(a) Install the overflow plug with a new gasket.
(b) Stop the engine.
(c) Install the refill plug with a new gasket.
(d) Install the transmission case cover with the two bolts.
Torque:
20 Nm (205 kgfcm, 15 ftlbf) for overflow plug
39 Nm (400 kgfcm, 29 ftlbf) for refill plug

jcdwrd

Thanks to both of you. I will print out your comments and bring them with me. I am supposed to meet with a area rep on the 27th.
My original thought was universals or the driveshaft spline. Turns out Lexus does not use universals anymore. And, even though I have mentioned the spline many times, they are resisting replacing it. The car was on extended Lexus warranty until a few months ago but the problem has been documented for 1 1/2 years.

Doublebase

If you heard the same noise out of the 08 loaner car, wouldn't that kind of ease some of your concern? At least you know it's pretty common. I think I have some sort of thunk that comes from the rear on occasion as well - mostly when braking suddenly. It almost sounds like a bushing or something suspension related. It doesn't bother me because it's not bad.

I have done the transmission service on my car and Lav is right, it's not the easiest thing to do to get the fluid level correct. I used a procedure that involved jumping a couple pins on the data link connector and followed a shifting sequence to get it into a transmission temp mode. Only then was I able to get it right. These cars heat up very very quickly, so it's not really something you can guesstimate. But with the loaner car having the same noise...maybe it's not something to worry about?

jcdwrd

Doublebase.
I paid $3000 for a extended warranty to cover things like this. And it is a $90,000 automobile. If I knew what is making the noise and it was nothing of consequence, thats one thing. But I don't know and neither does Lexus. That bothers me. In the search for it they have found a sagging rear suspension spring, rear suspension bolts rusted solid and a collapsing differential mount.
And again, I have driven two late model 8 speeds and both of them make the same noise. Too much of a coincidence.

roadfrog

There is no U-Joint, however there IS a flex disc or Guibo (or Giubo) joint. These can deteriorate to the point of causing thunk when downshifting etc. They are made of rubber and therefore, their longevity is not indefinite.

My 7 series BMW had this fail at 70k miles and the symptom's were a thunk when downshifting from 3rd to 2nd. I replaced it DIY and the problem dissapeared. Good news is, they're inexpensive and relatively simple to replace.

caha14

Yes! I now remember your posting this elsewhere, but the thought hadn't crossed my mind. Makes sense, and good to know/remember.

I'd imagine this would be included in a new driveshaft assembly, and hence, this is why this problem (among others) disappeared in my 460 with the replacement?

roadfrog

Correct. It is mounted between the front and rear driveshafts or between the trans and front driveshaft, depending on the vehicle.

Doublebase

Well I hope they find the problem to the noise. You mention vehicle price and the price of the warranty...I think when people look at price they think, I should never have a noise with this car, and that's not going to happen. The car is 8 years old now. I can buy an 07 LS 460 for $17500 off of craigslist right now. And I can guarantee that 8 year old car will be 10 times quieter than any other 8 year old car on craigslist.

Honestly I hope you get your money's worth out of that warranty, but you're never going to get your money's worth out of a $90,000 dollar car. It's not going to happen.

jcdwrd

Doublebase. I think you misunderstand my problem. The car was perfect until about 80k. Then this noise started and was quite loud. It has since quieted down but, it is not the kind of noise that should be coming from a healthy automobile. Something is wrong. It may not be a serious problem but Lexus should be able to find it and fix it or , at least, tell me what is causing it. If I wanted to live with things like this I could have bought a Ford for a lot less money. And I did not pay 90k for it.

Lavrishevo

iTrader: (1)

Any update in your situation JCD?

jcdwrd

Lavrishevo.
I met with a "Area Parts Rep" last week. He heard the noise but was unable to recommend anything helpful. If fact he said he didn't think it is anything to worry about.
I meet with another rep tomorrow ( Wednesday ). I am beginning to think that they just put a white shirt on anyone available and send them to patronize me.