Drive Shaft Clunk

[morg96ls400]

Hey guys I got under the rear of my car today, put the thing in neutral and manually rotated the driveshaft back and forth. I could hear a metal-to-metal clunk coming from the front of the car when I did this.

I was wondering two things:

1) Does this noise indicate a failing universal joint?

2) I also hear a loud clunk when I shift into R or D, but is sporadic. Also: there is some play in my neutral-shift-safety switch, which I can hear everytime I shift. It sounds like a "click."

Also: when removing the fuel filter should I loosen the larger bolt first (facing the differential) or the smaller one (facing the wheel)?

[morg96ls400]

bump

[SKperformance]

How do the bushings look ?

To remove the filter pull the fuel pump fuse and let the system drain the gas before removing the filter . It won't make any difference which end to remove.

[morg96ls400]

Bushings look fine from what I can see. Had rear carrier replaced a couple months ago, and dealership looked at all the suspension bushings to check for any others that might have gone. Funny thing is when the engine warms up or I shift enough times, the clunk noise almost goes away. I replaced my ECU as it had problems with dying on the freeway, and there is a heavy lurch whenever I go into D or R. I'm wondering if this could be the problem causing the drivetrain to wear down prematurely and hence destroying any "soft" parts in the drivetrain. Maybe differential mounting cushions? I couldn't see the inside in contact with the differential, but the rims of them look ok from what I could tell.

[90LS400Lexus]

Usually, that is the cause for a clunk or "clank". However, sometimes it is not and it can be serious. I had a car once that had that noise. We replaced the u-joints and it still did it. Come to find out, we think it was the actual gears in the axle that were bad. Big $$$$ to fix, unless it is a old RWD car.

Good luck.

[morg96ls400]

Apparently, there is no u-joint on the LS.

With this in mind, I have some symptoms that might be arising from the same problem:

1. Metal Clunk (or Clank if you will) when shifting into D or R.

2. Excessive vibration at 75-80 mph.

3. Rythmic rumbling when in Park on a cold start-up

When I got under my car and moved the driveshaft, I could turn it about 1/4 of a turn in each direction before having it stop and make a metal-on-metal noise. I'm not sure if this is "normal" (i.e. it should make a noise when it is in neutral and is moved manually with the e-brake on) or whether this metal noise is indicative of a failing spider-joint in the propellor shaft, or the center support bearing is making this noise etc etc.

I have a feeling that my tranny mount might need to be replaced, and im hoping that the driveshaft is not in need of replacing.

Either way I'm taking it in on thursday to have the dealer check it out.

[dfkd]

Apparently, there is no u-joint on the LS.

With this in mind, I have some symptoms that might be arising from the same problem:

1. Metal Clunk (or Clank if you will) when shifting into D or R.

2. Excessive vibration at 75-80 mph.

3. Rythmic rumbling when in Park on a cold start-up

When I got under my car and moved the driveshaft, I could turn it about 1/4 of a turn in each direction before having it stop and make a metal-on-metal noise. I'm not sure if this is "normal" (i.e. it should make a noise when it is in neutral and is moved manually with the e-brake on) or whether this metal noise is indicative of a failing spider-joint in the propellor shaft, or the center support bearing is making this noise etc etc.

I have a feeling that my tranny mount might need to be replaced, and im hoping that the driveshaft is not in need of replacing.

Either way I'm taking it in on thursday to have the dealer check it out.

←

Sounds kinda like the teeth on the tranny end of the shaft are worn down...have you looked at them at all?

Not sure what would wear those down other than some serious abuse...

[nc211]

Morg, I'm betting it's your tranny mount banging around. Post up what you find if you don't mind. I posted up my results under the wobble thread. Dealer said the lurch is normal for car this old and there is no real one silver bullet part that will fix it, as it's a part of the whole system. Thank the EPA for making Toyota program the car's computer to hold the 1,570 +/- rpm during warm up to reduce pollution. If you think about it, what car wouldn't lurch a bit at that idle speed? Or at least that's what I tell myself in the morning when mine does it! Hahaha. Keeps me sane. But in your case, I'm thinking tranny mount probably, and maybe those differential mounting bushings. I can't remember, didn't you tell me a while back that yours were torn too?

Apparently, there is no u-joint on the LS.

With this in mind, I have some symptoms that might be arising from the same problem:

1. Metal Clunk (or Clank if you will) when shifting into D or R.

2. Excessive vibration at 75-80 mph.

3. Rythmic rumbling when in Park on a cold start-up

When I got under my car and moved the driveshaft, I could turn it about 1/4 of a turn in each direction before having it stop and make a metal-on-metal noise. I'm not sure if this is "normal" (i.e. it should make a noise when it is in neutral and is moved manually with the e-brake on) or whether this metal noise is indicative of a failing spider-joint in the propellor shaft, or the center support bearing is making this noise etc etc.

I have a feeling that my tranny mount might need to be replaced, and im hoping that the driveshaft is not in need of replacing.

Either way I'm taking it in on thursday to have the dealer check it out.

←

[morg96ls400]

Glad to hear about your fix nc, and yeah I'm thinking the tranny mount is the first thing I'm going to replace. I looked at the diff mount cushions but I couldn't see any tears or anything, I think i'd have to remove them to actually see the actual condition behind the differential. Expensive fix for those, but the tranny mount I think I can handle myself, just as soon as the rain subsides for a day or two.

[nc211]

Morg, have someone "you trust with your life" help you on inspecting the diff bushing. Put the e-brake on, and have the person with one foot on the brake ped, shift the car into Drive. While they're doing this, you'll be on the ground, behind the car with a flashlight. Don't crawl under the car as it will shift downward when it goes into drive, but be right behind it. Look at the driver's side differential bushing when the car is in D. Is it torn? This method will show it's flaws if it is torn. It will always sag a little bit towards the bottom, even my new ones do that, but the internal medal ring should not be touching the external metal ring. This will tell you if the bushing is toast. Funny thing, the dealership says those parts rarely ever go out, but it's pretty clear on here anyway that they do go out and can get ripped apart. Especially on the 95 & 96 models that have ever had the off-throttle-shock syndrome.

[ArmyofOne]

Morg, I'm betting it's your tranny mount banging around. Post up what you find if you don't mind. I posted up my results under the wobble thread. Dealer said the lurch is normal for car this old and there is no real one silver bullet part that will fix it, as it's a part of the whole system. Thank the EPA for making Toyota program the car's computer to hold the 1,570 +/- rpm during warm up to reduce pollution. If you think about it, what car wouldn't lurch a bit at that idle speed? Or at least that's what I tell myself in the morning when mine does it! Hahaha. Keeps me sane. But in your case, I'm thinking tranny mount probably, and maybe those differential mounting bushings. I can't remember, didn't you tell me a while back that yours were torn too?

Apparently, there is no u-joint on the LS.

With this in mind, I have some symptoms that might be arising from the same problem:

1. Metal Clunk (or Clank if you will) when shifting into D or R.

2. Excessive vibration at 75-80 mph.

3. Rythmic rumbling when in Park on a cold start-up

When I got under my car and moved the driveshaft, I could turn it about 1/4 of a turn in each direction before having it stop and make a metal-on-metal noise. I'm not sure if this is "normal" (i.e. it should make a noise when it is in neutral and is moved manually with the e-brake on) or whether this metal noise is indicative of a failing spider-joint in the propellor shaft, or the center support bearing is making this noise etc etc.

I have a feeling that my tranny mount might need to be replaced, and im hoping that the driveshaft is not in need of replacing.

Either way I'm taking it in on thursday to have the dealer check it out.

←

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I would check, in the following order:

Tranny mount

Diff Mounts

Carrier Bushings (since your under there, they arent likely to be the complete problem, but they will magnify it if they are bad).

as has been said, the lurch is normal. I wasnt aware about the idle speed, but at that RPM, ANY car would jump significantly when shifted from park to any gear.

Does this lurch feel at all like a the lurch you get when you put a manual trans in 1st and let off the clutch without giving it gas, it jumps forward, right?

EDIT: i missed the part where you said you replaced the carriers a couple of months ago, so disregard that last part.

Im going out on a limb here, but could the ckank you get when shifting be a loose heatshield somewhere? I have seen this a few times on the humvees, whic idle abnomrally high (1200 RPM is HIGH for a diesel to idle) loose heatcheld is just loose enough to clank when it shifts from N to D. Doesnt do it any other time. the only reason i mention this is because you mentioned it was more of a "clank" than a clunk.

[morg96ls400]

Just got in from helping a buddy from work change his rotors, and i realized something. When I went into my car and gassed it in neutral, the whole frickin car shook as I increased the rpms. It feels like the whole car is moving side to side, wobbling if you will, when there is alot of instant torque put on the car. I ordered a tranny mount from park place plano for 32 bucks, and I'm going to have the dealer check my struts for any twisted shock absorbers on thursday. I'll keep you guys posted.

[morg96ls400]

Ok so I just got back from the dealer and I have a laundry list of things to fix.

the "gurgling" or "sprinkler" noise when I press on the gas pedal is due to my cracked egr pipe.

The clunk or clank I hear when shifting into D or R is due to broken motor mounts + tranny mounts

My rear brakes need replacing.

Tires are in need of balance, plus an alignment.

Ok so This is what I'm going to do:

Replace the motor and tranny mounts myself, have an indie do the egr for cheap, get new tires, put new rotors and pads on myself, replace fuel filter, and clean throttle body.

Questions:

How hard are the motor mounts to replace? If I have my buddy help me will this be feasible or should I just have a mechanic do the motor mounts?

Also, when changing the rotors and pads, is bleeding necessary if I don't open the brake line, but rather just use a punch to push the pistons in when I remove the caliper?

As for tires, anyone have experience with the michelin pilot a/s and mxv4? which ones should i go for between those two?

Thanks!

[nc211]

Morg, ok, got a game plan now. The brakes do not need to be bled. I replaced all of my rotors and pads myself, and didn't have to bleed anything "except for my knuckles". I recommend when you're changing them to have a few cans of brake cleaner spray on hand to clean up the piston and pad housing. Oh...hand use some rubber gloves too, I learned that the hardway and cost me a trip to the dermatologist. DON'T OVER TORQUE the little screw that holds the rotor in place, you'll see it when you're in there. There's only one, and the threads will strip faster than Anna Nicole Smith for $50! Take it nice and slow on those. If you do strip them, the dealership should have plenty for you to buy at like $1 a piece. MAKE SURE you remove the shims on the back of the old pads, clean them, and put them back on the new ones. The tech manual says to just push the piston back when sliding onto the rotor. If you need a pdf on the process, let me know and I'll post it up.

Motor mounts: Depends on your tools and ability. The driver's side is a serious pia! I paid my local indi to do those because I couldn't handle it myself. Cost like $80. The tranny mount is cake, and there's a recent thread on here about it.

EGR: Mechanic.

Fuel Filter: make sure tank is pretty close to empty for safe keeping sake, and have some fuel in a container on the side just incase it all drains out of the tank by accident. I've heard it's an easy but messy job.

Mich tires: I haven't a clue. I've got mvx4's, they've been good so far. I've got about 8,000 miles left of tread and have some problems with two of them.

[morg96ls400]

LOL thanks for the advice about the rotor screw, it is good to know that I don't have to bleed the brakes. And yeah I will probably get the motor mounts done by my indi because it looks like the steering gear needs to be dropped in order to get to them. I guess I'll go with the pilot a/s from costco then, and have an alignment / balance done at the stealership.

Thanks again!

[ArmyofOne]

Morg, ok, got a game plan now. The brakes do not need to be bled. I replaced all of my rotors and pads myself, and didn't have to bleed anything "except for my knuckles". I recommend when you're changing them to have a few cans of brake cleaner spray on hand to clean up the piston and pad housing. Oh...hand use some rubber gloves too, I learned that the hardway and cost me a trip to the dermatologist. DON'T OVER TORQUE the little screw that holds the rotor in place, you'll see it when you're in there. There's only one, and the threads will strip faster than Anna Nicole Smith for $50! Take it nice and slow on those. If you do strip them, the dealership should have plenty for you to buy at like $1 a piece. MAKE SURE you remove the shims on the back of the old pads, clean them, and put them back on the new ones. The tech manual says to just push the piston back when sliding onto the rotor. If you need a pdf on the process, let me know and I'll post it up.

Motor mounts: Depends on your tools and ability. The driver's side is a serious pia! I paid my local indi to do those because I couldn't handle it myself. Cost like $80. The tranny mount is cake, and there's a recent thread on here about it.

EGR: Mechanic.

Fuel Filter: make sure tank is pretty close to empty for safe keeping sake, and have some fuel in a container on the side just incase it all drains out of the tank by accident. I've heard it's an easy but messy job.

Mich tires: I haven't a clue. I've got mvx4's, they've been good so far. I've got about 8,000 miles left of tread and have some problems with two of them.

←

One word on tires:

Falkens:

www.falkentire.com

the ZE512. I swear by them.

[morg96ls400]

So, I did a few things over the past couple weeks.

First, I cleaned the throttle body-faster response on the gas pedal, cleaner, more nimble acceleration.

Second, I had the motor mounts changed. Wow, difference was amazing.

Third, Got new tires, no falkens at costco, so I went with the michelin mxv4 energy luxury touring. Nice tires, 150 a pop, but the car drives smooth as glass now.

Fourth, replaced the tranny mount this afternoon myself. Easy as cake, and now it seems all the problems are fixed.

No more vibration at 75-80 mph. No more clunk noise when shifting. Lurch is very reduced. Smooth idle, drives like new (or how I would imagine it to feel new).

So it seems all I need to do now is the brakes, egr pipe, and drive belt (which I ordered from park place, will put that in on thursday) to get rid of squeeling noise, now temporarily gone thanks to wd40.

Anyways, it seems that I have the car that I thought I bought back in february. Feels good. Thanks for your guys' help!

[dpusa55]

REPOST FROM ANOTHER TOPIC!

I would like to make a substantial contribution to this and lots of other posts about mysterious clunks in LS400-LS430 vehicles.

As you all guys know there were numerous attempts to identify the actual location and cause for major clunk and squeaking sounds coming "Somewhere" from the wheel area. We have all went through replacing bunch of parts with no success to fix the problem.

I have to say that I finally found what is the most probably cause for these clunks. Go to your mechanics and replace front left wheel hub and front right wheel hub. You will be amazed how quiet your car becomes. It is really unbelievable how simple the problem was.

[billydpowell]

well you are doing better, this post is only 11 years old.