car shaking under acceleration, Please Help!!

[1997hciv]

I have searched this topic and have not found many instances like mine. Ok so when I start going from a stop my car will shake when I hit 2nd gear at about 2k prm up to about 5k rpm. When im going about 50-60 mph and acclerate it will shake again. When I let off the throttle the shaking goes away. I do need an inner cv boot because it is ripped but the timing belt looks fine and I only put in the front and driver side motor mounts while the transmission and rear motor mount are still stock. The car has 98,000 miles and is in great running condition. Please help!!!

 

[housegsx]

Check your driveshaft carrier bearing.

 

[1997hciv]

Thanks for your help. How do i tell if its bad or not.

 

[housegsx]

I dunno. I'd say put the car up on jack stands and grab the driveshaft on each side of the carrier bearing and try hard to move it around in the bearing up/down side/side. And if you noticed it was sloppy when you take it off the rubber should look worn/torn etc.

 

[1997hciv]

Ok so I went for a drive and noticed that the car only shakes when its at a lower rpm and the throttle is 60-100%. When I drive normal with a light foot it does not shake. What else do you think it could be? I agree with the driveshaft carrier bearings but I have not had a chance to check it due to school. Any help would be great.

 

[InfiniteGSX]

Also, check wheel Lugs... When mine were really lose, the wheels would vibrate.

 

[madtech707]

Your symtom sounds alot like a bad axle shaft/joint. I would say if you feel the shaking in your seat or the floor board look towards the drive shaft carrier, u joints, or rear half shafts. If you feel the shaking in the steering wheel suspect one of the front half shafts.

 

[1997hciv]

The shaking is mostly in the seat, floorboard and the whole car in general. The steering wheel does not shake to where it is noticable.

 

[rc000e]

It definitely sounds like the carrier bearing. Check the vfaq for a fix on this issue.

 

[iammikesevvy]

i have the same problem as you...does your check engine light come on?

 

[coryd]

i have the same problem as you...does your check engine light come on?

A worn out carrier bearing wont cause the CEL to come on

 

[1997hciv]

No my CEL does not come on. I will try and fix the carrier bearings over thanksgiving break and let you know if it was the culprit. Thanks for the imput.

 

[bsbob]

I dont know if you've figured out your problem, but I just had the same problem by the description. Shaking really bad especially at highway speeds, so i replaced both my front axles (which was a huge bi*** due to rust and confusement of Napa on which ones i needed, and replacing my drivers wheel bearing, brake disc, and knuckle), but when all was said and done, My problem has completely vanished and my car is smoother than it has ever been. My Uncle is a Mechanic and that is what he said to check for me, he said any tears can allow in some dirt and cause the vibration.

 

[AZDSM]

Also, check wheel Lugs... When mine were really lose, the wheels would vibrate.

I 2nd this, even though it probably isn't the problem for this case. However it is always smart to keep an eye on the lugs and check them every once in a while. Mine had a tendency to vanish every once in a while and I recently had 2 wheel studs replaced. Which ended up being the culprit.

 

[turbobird14]

simple thing could be wheels out of balance... this would more likely be the wheel shaking also with the lugs being loose. i would definately replace the cv shafts... once the boots are ripped the joints are contaminated and are done... you could rebuild your CVs but i would get new ones.

 

[tenn-gsx]

tire balance would shake on or off throttle. Only thing that would make a difference is speed.

 

[bane3d]

simple thing could be wheels out of balance... this would more likely be the wheel shaking also with the lugs being loose. i would definately replace the cv shafts... once the boots are ripped the joints are contaminated and are done... you could rebuild your CVs but i would get new ones.

I agree with this response. The first thing I would do is take it in for an alignment and balance. It's fairly cheap and most of the time, you need a tire rotation anyway. Just get it all done. If you are on a budget and don't have much time, this would be the quickest and easiest thing to factor out. Once you are sure your wheels are good, then start working your way in from there.

d

 

[bjbaxter]

Try checking the "curved" lower control arm as well. If the ball joint on the one end is bad it will cause the car to shake. Its easy to check; Jack up the front with the wheel on and shake the tire left and right. If there is any play in it, it usually means that "curved" lower control arm needs to be replaced. Let us know how u make out.

 

[transtlye]

my buddy just had the same problem and it was his axle. Be carfull because it snapped in the cv boot before we figured it out and he had to get a tow.$$$

 

[1997hciv]

Thanks for all of the replies. Its not the lugs or anything simple and cheap. I didnt have time to replace it over thanksgiving so I left it home and now that im back from school its ready to be fixed...yeaaa. yea the problem is not rev rlated or not even speed related really. Its the amount of torque load t he car has on the worse it gets and then it just gets worse when it is floored at the higher rpm, but when i am feathering the gas all the way up to 5k it wont shake. So, I ordered 3 yoke replacement kits to replace all of the u-joints and I ordered a new front cv shaft. I will be taking the rear driveshaft off to pump the carriers with silicone and put the new yoke in along with the u-joints. I will also put the new cv shaft in when it arrives. I let you know if my problem will be solved.

 

[1997hciv]

So I replaced all of the u-joints, the yoke and the front left cv shaft and the shaking is gone. now since I filled the carrier bearings with silicone my car feels like I just put another set of urathane motor mounts in. Problem solved!!

 

[Tomcat5678]

Hello. Kind of a long time listener, first time caller. I own a 1992 Plymouth Laser RS (AWD) and I am experiencing the exact issue 1997hciv is/was describing. Under load the car vibrates and it seems like it is even worse while going around right hand sweepers (points towards the left half shaft). Floorboards, shifter, steering wheel as well. I am going to try and replace the same things 1997hciv did but had an additional oddity I wanted to mention and get opinions on.

One day it was at a stop sign and turning right and it had just rained so the roads were slick. I floored it around the corner and the tires broke loose, back end came out to the left a little and then the car snapped straight ahead and I continued on. For the next 10-15 miles home the car was COMPLETELY smooth! Any thoughts other than what has been posted already?

Thanks.

 

[Jay Zarcadius]

I experienced something similar to this, I have a 91 Non-Turbo car. Mine was somewhat the same, under hard throttle at lower speeds, mine is almost solved now and believe it or not it wasn't a suspension issue at all. Not sure if your vibration is the same as what i experienced, but i'm been slowly adjusting my ignition timing and its getting better, mine's almost completely gone now, I think mine was to retarded too much, so i advanced it a bit and the vibration didnt happen much, a little more adjustment and it got a little better, now it's almost completely gone. I haven't moved t much each time, just barely tapping it to move it a couple degrees, i didnt want to over adjust it.
Like i said not sure if yours is the same, but it couldn't hurt to check it.