2000 Lexus LS 400 shudder

JIM TREBONSKY

MEMBER
2000 LEXUS LS 400
V8
2WD
AUTOMATIC
103,567 MILES

Thanks my lexus has a shudder from about 35 to 43 mph, I am a ase cert tech with 10 years gm exp and 20 yrs honda exp. I have done all basics, tires, wheels, mounts. This car is killing me, engine on or off it shudders when you enter the 34 to 43 mph range on accel as well as coast down. It is dead smooth above or below this speed. I installed another drive shaft - no improvement, conditions gets more pronounced as ambient temp goes down. I WILL DONATE MONEY IF YOU CAN HELP THANKS JIM

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Saturday, January 9th, 2010 AT 7:31 PM

18 Replies

MERLIN2021

MECHANIC
17,250 POSTS

Start here to find out if the tranny has a mechanicl problem or not.
MANUAL SHIFT TEST 1. With ignition off, disconnect transmission solenoid connector. See Fig. 6 . Road test vehicle and ensure transmission gear changes correspond with selector lever position. See GEAR APPLICATION table. 2. If abnormality exists, a mechanical transmission problem exists. Turn ignition off. Reconnect electrical connector. Clear trouble codes from ECM memory, as disconnecting electrical connector may set a trouble code. See CLEARING DIAGNOSTIC TROUBLE CODES under DIAGNOSIS & TESTING. NOTE: Perform manual shift test if no trouble codes exist. Manual shift test determines if problem area is in electrical circuits or a mechanical transmission problem.

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Sunday, January 10th, 2010 AT 11:20 AM

JIM TREBONSKY

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Merlin thanks for the quick reply, this problem is a vibration or shudder you can feel in seat and floor. It is on accel, coast, cruise, in neutral, or any gear, even with engine not running

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Sunday, January 10th, 2010 AT 2:11 PM

MERLIN2021

MECHANIC
17,250 POSTS

Seems like it's when engine and tranny are in one to one ratio, possibly the torque converter or a forward clutch. Any codes present? Condition of the fluid?

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Tuesday, January 12th, 2010 AT 2:24 PM

JIM TREBONSKY

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There are no codes stored, the fluid is very good, I change regularly. It is much more noticeable when ambient temp is low. It does when the engine is shut off. Thanks JIM

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Tuesday, January 12th, 2010 AT 7:40 PM

MERLIN2021

MECHANIC
17,250 POSTS

Try testing the shift solenoids, it can be done with an ohm meter, heres how:NO. 1, NO. 2, NO. 3 & NO. 4 SOLENOIDS 1. To check solenoid seals, remove suspect solenoid. Connect battery voltage to solenoid. Apply 71 psi (5 kg/cm 2 ) to solenoid with battery voltage connected. 2. With battery voltage applied, air should pass through solenoid. Disconnect voltage to solenoid. Ensure air does not pass through solenoid. Replace solenoid if defective. 3. Using ohmmeter, measure resistance between case and solenoid connector terminal. Resistance should be 11-15 ohms. Replace solenoid as necessary.

SLN, SLT & SLU SOLENOID Raise and support vehicle. Remove transmission oil pan. Remove appropriate solenoid. See Fig. 1 . To check solenoid operation, connect positive battery voltage to solenoid terminal No. 1. Ensure an 8-10-watt bulb is placed in-line of positive lead. See Fig. 12 . Connect negative lead to terminal No. 2 and monitor valve's movement. Replace as necessary.

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Wednesday, January 13th, 2010 AT 1:55 PM

JIM TREBONSKY

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MERLIN, DO YOU THINK THIS PROBLEM COULD BE CAUSED BY THE TRANSMISSION IF I SHUT THE CAR OFF AND IT STILL OCCURS. THANKS JIM

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Thursday, January 14th, 2010 AT 7:50 AM

MERLIN2021

MECHANIC
17,250 POSTS

Let me get it right, car is off, and your doing 35-40 mph, and it has a chatter, or vibration in the drivers seat area? Car is in drive? Tranny would still be spinning internally, and engine too. Backfire when you restart? Key if OFF position? On? I checked for PCM reflashing on this, no TSB released to Mitchell on demand, but it may be worth a trip to Lex dealer to check if they have any info. Many issues are solved with a reflash. Other than that when you removed the pan last time was there any friction material or steel in the bottom? Direct clutch is what I'm thinking.I work on mostly Ford, Lincoln, Merc, and new wires and plugs can even solve it on these cars, On LEX not sure, but any weakness in tune up parts can be exposed during this shift point. But with engine off, I doubt it's the tune up. What does it do if you shift to neutral?

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Thursday, January 14th, 2010 AT 12:53 PM

JIM TREBONSKY

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This vehicle has a shudder, very simillar to a drive shaft out of balance, this is not a trans clutch shudder. It will do it with the engine shutoff. It is much worse whe the ambient temp is cold, its hardly noticable in summer when it is hot. I have driven cars with auto trans clutch shutter and this completely different the engine and trans on this car are as smooth as butter

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Thursday, January 14th, 2010 AT 9:24 PM

MERLIN2021

MECHANIC
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The only thing left then is mounts, but you did say yours were good? You know how this goes Jim, if I cant drive this, and there are no tech bullitens about it, It's guesswork.
The differential is a hypoid-type with integral carrier housing. The differential is mounted with rubber mounts in the rear suspension member. The drive shaft is a 2-piece design, supported by a center bearing. You have checked these mounts, and the center bearing? The center bearing is THE most common problem area on these and BMW. Why yours only does it in 3rd? But I have seen stranger!

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Friday, January 15th, 2010 AT 4:48 PM

SAMSLAM

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Jim did you ever figure out the problem? I'm having the exact same issues, its driving me crazy

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Saturday, June 2nd, 2012 AT 5:34 PM

RIVERMIKERAT

MECHANIC
6,110 POSTS

Jim and samslam, have you checked the axle bearings? Or the ring and pinion for alignment issues? Maybe a loose U-joint? Or a U-joint cap missing a needle bearing or two. Double check the rear shocks, leaf springs, etc. Make sure you aren't experiencing a tread sep issue, or a tire cupping issue.

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Wednesday, July 25th, 2012 AT 2:54 AM

CTUBA

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Jim and samslam, did you guys every find out the problem with the vibration? I have the same issue. It gets worse when the weather gets colder.

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Monday, February 11th, 2013 AT 3:03 PM

RIVERMIKERAT

MECHANIC
6,110 POSTS

Ctuba, have you had it in a shop and had them pull ALL codes, both hard AND soft? Soft codes don't cause any of the lights to come on, but can reveal problems.

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Thursday, April 4th, 2013 AT 2:39 AM

SMOKEY2705

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2 POSTS

Hi Guys
I had a similar problem with an SC400 and it turned out to be the type of ATF that had been used in the transmissio. You must use Toyota Genuine ATF Type IV to ensure that the vibrations are removed. If you've used Dexron or similar you may need to change it a couple/few times to remove any trace of it.
Best of luck.

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Wednesday, April 10th, 2013 AT 9:40 AM

RIVERMIKERAT

MECHANIC
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Thanks for the heads up there Smokey. Hopefully the guys having the problems will see your update.

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Saturday, November 9th, 2013 AT 3:53 PM

SMOKEY2705

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I had a similar experience with an SC400 1994 model. After a lot of testing etc I found that the use of Dexron automatic transmission fluid was the culprit. Toyota/Lexus have specified a particular type of fluid and that only can be used. Try changing the fluid with Type IV from your local dealer, drive it for a while then change it again to try to get as much of the Dexron out of the system. It worked for me.

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Saturday, November 9th, 2013 AT 6:18 PM

DRAGONEDDY

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A while back this was posted

"Try testing the shift solenoids, it can be done with an ohm meter, heres how:NO. 1, NO. 2, NO. 3 & NO. 4 SOLENOIDS 1. To check solenoid seals, remove suspect solenoid. Connect battery voltage to solenoid. Apply 71 psi (5 kg/cm 2 ) to solenoid with battery voltage connected. 2. With battery voltage applied, air should pass through solenoid. Disconnect voltage to solenoid. Ensure air does not pass through solenoid. Replace solenoid if defective. 3. Using ohmmeter, measure resistance between case and solenoid connector terminal. Resistance should be 11-15 ohms. Replace solenoid as necessary.

https://www.2carpros.com/forum/automotive_pictures/62217_sols_1.jpg

SLN, SLT & SLU SOLENOID Raise and support vehicle. Remove transmission oil pan. Remove appropriate solenoid. See Fig. 1 . To check solenoid operation, connect positive battery voltage to solenoid terminal No. 1. Ensure an 8-10-watt bulb is placed in-line of positive lead. See Fig. 12 . Connect negative lead to terminal No. 2 and monitor valve's movement. Replace as necessary.

https://www.2carpros.com/forum/automotive_pictures/62217_slu_1.jpg"

Can anyone tell me if they tested this? I dismantled two A560E transmissions and in both of them shift sol #4 does not have a spring to close the solenoid. This with no power connected it still allows flow.

Is this a fault? Or is the post Incorrect?

Thanks in advance

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Monday, April 25th, 2016 AT 2:57 PM

RIVERMIKERAT

MECHANIC
6,110 POSTS

I would say this is a fault Dragoneddy. That being the case, it could be the post was incorrect, although that would be quite rare as the information that was given came directly from Toyota/Lexus.

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Thursday, July 28th, 2016 AT 10:47 AM