NC211

Hey all, got a question and curious if anyone has any suggestions..... Sorry for any typo's, got a typical summer cold and head full of dayquil.

I have a 95' LS400 with 88k on it. I recently replaced the transmission mount in hopes to solve the issue, no luck. I have vibration coming from what feels like the front of the car. It comes and goes when on the freeway, but it is always there when I'm accelerating. It not only shakes in the steering wheel, but it also shakes the whole car. It's really noticable when going up a hill at normal and sustained speeds. I don't know if this is related, but I have a noticable "Thump" when the engine first starts, especially if it's been sitting for a while. Right when the engine engages is when it "Thumps." It sounds like metal on metal. I did a visual inspection under the front, looked at the bushings on the A arms and so forth. They do look old, but not cracked or squished beyond normal use. Infact, there was space between them and the metal they insulate from. Any suggestions??? Motor mount maybe? When I had the transmission mount replaced, the old one looked fine, go figure? It also shifts a bit harshly too, not very smooth gear engadgement. Really noticable when putting car in D or R, it lurches, badly!

Thanks in advance for your inputs. This site saved me tons of money in regards to the main ecu unit a few months ago.



market dictates price, knowledge holds the answer.

NC211

Opps, forgot one thing, the vibration disappears when you take your foot off the gas and just coast, even the steering vibration. Think I got a bunch of issues....

CUMan

I'm not sure that it is the same problem that you are having, but the first generation LS models are known for a "shudder" in the transmission. The problem feels very similar to running over the bumper strips that are put on roads to alert people to slow down. It seems to occur most often when one is accelerating in the 40-50 MPH speed range and going up an incline. The shudder occurs when the transmission either comes out of lock-up or downshifts.

My 93 LS did this for about the first three years that I owned it. When I had the transmission fluid drained and refilled, the shudder stopped. That was sometime in 2001. The shudder has never returned.

Do a search under "transmission shudder." There are quite a few threads about this.

98 LS

1) Sounds like front ball joints ..............

and

2) A failed motor mount(s) ..........

NC211

Thanks guys, I am thinking it is an actual part that is worn out. I had the 90k service done on it at 85k a few months ago when I bought it, which included new transmission fluid. I checked the fluid and it was clean. I bought it from a lexus dealership here in raleigh. I'm thinking the ball joints might be a major part of the steering vibration, although there is no free play in the steering. But there is a "clicking" noise starting to happen when I am pulling into a parking place and turning the wheel. I had the wheels all balanced a few weeks ago in an attempt to fix it before a long road trip. I noticed while on the road trip that after I inflated the tires 4 more psi to 36, it smoothed out quite a bit, but it's doing it again. Would the engine mount cause the severe lurching when putting it into gear? I opened the hood over the weekend and did the test where you put on the brake, put it in the gears and watched to see if the engine moved a bit, and it did a little, but not too much. Do you think it could be a transaxle mount in the back that is worn or loose?

Cuman, what part of Bama you from? War Eagle or Roll Tide? I'm a former B'ham man myself and I miss the Purple Onion restuarant like you can't believe.

Thanks guys

Stefwilli

Sounds like the drive shaft. My uncle has a 95 SC and thats what the problem was on his car for the shaking while accelerating.

CUMan

I'm a UAB man - class of 1979 (Accounting). However, we rarely mention their football team.

Roll Tide!

NC211

Roll Tide!!!
Red Mountain Express Way w/o traffic is a great little road! Used to work in the Southtrust tower downtown. Years ago my dad used to work for Protective Life. I miss ole' Bama! But Raleigh isn't bad either, it's lot like B'ham. Anywho, Stefwilli "nice tag" do you remember what your uncle had to do? Was it just out of balance and was a quick fix? Please don't tell me he had to replace the thing, can't afford that. I'm thinking a motor mount is bad inconjunction with the drive shaft being out of balance. I got a feeling there are a handful of little items coming up on a 9 year old car. Bushings, balljoints etc.... Probably gonna just dump a grand into it and drive it till the wheels fall off. I replaced a 2001 maxima se "got from riley nissan in sylycaga, al" for a 95 ls400 4 months ago and have no regrets. What a smooooth riding machine. Love a V8! Especially one that gets 25+ mpg! Not looking forward to winter weather though, no traction contol and a 45 degree driveway. Should be fun!

Roll Tide!!! "and keep the coach out of the strip clubs"

jonny2k

BUMPING this up from the dead!!

My father's LS400 is doing the exact same thing. Had a FULL tuneup done, replaced both control arms, ball joints, and (at least) one motor mount although I can't remember which one. Is there a chance this could be U-joints or a tranny mount??

Thx in advance!!
~Jonny

Bali26

Engine Mounts.

jonny2k

Well I kinda thought that it could be mounts and I'll make sure they all get inspected. Here are a couple of additional notes:

1) The vibration almost seems rotational. In other words it feels as if there is something out of balance and it's really noticeable when idling in gear at a stoplight....even in Neutral.

2) When under load, or accelerating, the vibration is substantial. When coasting there is no vibration.

In researching further here on CL I found that the propeller shaft along with the center support bearing that sits between the two shafts may be the culprit. I'm hoping that if it's just the support bearing it could be replaced at a relatively moderate cost. The dealer cost of the whole assembly is over $800!

Photoinc

To check a motor mount, you raise the hood, start the car, put it in drive with your foot on the brake, and give it some gas. You will see the motor stand up on one side if the mount is broken. It will move some with a good mount.

trukn1

Failed motor mount, or possibly even a drive shaft bushing that is worn out.

CarguyinGa

Oh lawd!!! Rule out driveshaft and broken mounts if it's a problem sitting still in neutral, that sounds like a possible misfire occuring. Don't get too complex or presume it to be the same thing yours was. If it idles rough, look at the ignition system really close. Plug wires and coils are not uncommon failures.

PureDrifter

iTrader: (10)

mine had similar symptoms from a toasted trans mount...