Ok so i have had thsi shudder/vibration since may and have not been able to pinpoint its origin. Shudder starts at around 20 and is acceleration dependant. Meaning if i grandma the car it will be fine but the harder i get in tot the gas the more violent the dshudder gets and there is no steering wheel shake but more in the butt shake. I really cant tell the location of it but feels like it is in the middle to front.

I have checked:
rear end busdhings
shocks..tightened all bolts
checked rear bearings
tightend and checked rsb all rubber is good

replaced both drive axles
tightened all susp bolts under front such as control arms, frame mounts and such
checked play in front end and tight
switched to winter tires

one thing i came across which i thought of months ago but never went forward on is the engine mounts. Ive been reading a lot of post stating that the engine mounts have had these symptoms and they fixed it by replacing them. I have checked (by myself ) the load test and would say the front of the engine will rise maybe between 1-2 inches and the back more. SO if i put it in reverse and give gas the back will go up about 2-3 inches.

Im at a loss and the shake and shudder is killing me. COuld this be the problem. Also at highway speeds i have no shudder., if im on a main road and have slight throttle or coasting i have no shudder. Seems once i get to 50 the shudder is gone unless i hammer the gas but the shudder isnt as bad as it is at low speed

Any thoughts

 

I went and tried to load my motor mounts. In reverse, the engine seems to move about the same as yours, maybe a little less. And the same comment goes for the front.

I replaced my front mount a couple months ago because last fall it leaked all the oil out. I continued to drive it and eventually I noticed a clunking sound as I drove over rough road at low speed. Then I noticed that when I turned the engine off, I would hear the clunk as the engine shook a little.

But in your case I was wondering if it could be either ignition coils or gas supply. P0300 (multiple mis-fire) could cause the CEL light to flash while it is happening and then go off. Fuel supply would not cause a CEL, at least I don't think so.

 

Check it while the car is stationary. Is the shutter RPM dependent or speed dependent? Pop the hood and have someone rev up the engine while you look at it. See if it can be reproduced with the car sitting still.

 

if i have the car in park ort nuetral the engine revs great. NO miss or sputter or anything. Only once i get her rolling and get up to 20 or so. The shudder depends on how hard i get in to the gas. Little shudder w little gass and violent shudder w alot of gas

 

Transmission? Torque converter shudder? How many miles and any fluid changes done on transmission? Level? Color?

 

one thing i forgot to mention. Say back up then shift to drive i get a bang. Not a cringe kinda bang but none the less a bang when going back to drive

 

food for thought

in the tire business, vibration from the seat usually comes from the rear wheels, steering wheel shake is the front

the clunk between drive and reverse can be from low fluid. have you checked the fluid level?

is the engine making power as it should?

what brand axles did u get? theres a thread in fs section where member is looking for oem axles, bc hes had 3-4 brand new sets of them vibrate under load

 

If it was from vibration, wheels, axles etc the issue should get worse as you get faster, no?

I'm thinking the problem lies fully in the transmission. Jeff, do you notice the vibration starts/ends with the tranny shifting? Or at least seems to occur in a certain gear only? Assuming it's an automatic..

 

as i stated i have changed everything out or took it off and cleaned and replaced. Meaning this shudder started in May or so and back in july i changed the axles to new ones. Also was running summer tires and today switched the tires and rims to snow set. Problem still persists so i am ruling out rims, tires and axles. Just checked the tranny fluid and up where it should be and a nice clear red and no burn smell. The vib doest get worse so much as i go faster but the more throttlew i give it. Once im in cruising speed or hiway i have no shudder. Engine still has awesome power no drop in it. Axles are from carquest i believe but again after changing them there was no differecne in shudder. Yes it is an auto and i havent noticed gear specific. When i take it out in a bit ill check that as well

Hear are some pics of the MM's
Front.. pic is sideways due to phone


rear

 

in majority of cases, but not necessarily. but im not disagreeing with your trans idea, just throwing some ideas. automatics are one of the few things that i never fully understood. im trying to get my grant to cover a few tranmission classes as electives while im in school.

 

oh forgot to mention. Had the car on the lift and had the car in drive while wheels were in the air. Shut TCS off and let her go. Got up to 5k and about 55 mph and no shake maybe just a slight slight slight vib. But i had to sit and actually feel for the vib. My thought in this is maybe the mm as there is no road force in the air and the engine is free to move the tires while not having to move the weight of the car therefor the engine really has no reason to jolt or jerk

 

You can hear/feel/see when the auto trans shifts gears so I'd go for a drive and make a mental note when it upshifts/downshifts and keep track of what gear you're in. Then when you get the vibrations/shutter happening change your driving to force a downshift or upshift and see if it goes away.

Also, you checked the transmission fluid with the car at operating temp right? Because when you check it cold it should be overfilled. Then when it warms up and it's in gear it should drop down to normal levels.

 

ok, yea i checked it running at op temp. was up to where it should be, Also checked to see what gear the shudder was in... all of them. Took off out of my road and it went thru 3 gears and all the gears had the shudder....

 

Do you have fix a flat in any of your tires? also Try unplugging the front engine mount it should be an electric mount, try unplugging it and see what happens.

 

Yeah, unplug them all. I will clarify instead of "see what happens", that the electric motor mounts can go bad, and fry your ECU. There is a chance its screwing with something.

I HIGHLY doubt this is whats wrong.

 

no, no fix a flat. All tires are good like i said i tried 2 different sets of tires and rims. ALso tried unplugging the mm plug a couple months ago. Ill try again i dont remember if it did anything.

 

This is odd because it sounds like it is a wheel/tire problem. I have the same issues from about 60MPH to 70MPH and I can see a different when I rotate my wheels/tires.

Did you try rotating your previous set of tires/wheels first before changing over to winter? I wonder if you experienced anything different.

 

who do you use for your tires? they should be able to fix that and not just rotate it around

 

Not a tire issue...see my other thread with wheels. It is two bent wheels that are beyond repair; I have tried multiple wheel repair shops to no avail. The wheels function fine, but the vibration is very annoying to a point where I'm buying new wheels.

 

had my wife this morning get in the car and rev it while i looked at the mounts. The mounts are not full rubber. The top of the mount has a void im guessing to aid in nvh control. When she revved it easy and fast the front center bolt that goes thru the middle of the mount to hols the subframe to the mount raises about 1 inch. Same for the rear. Is this normal?

 

I think your mounts are ok. if you had a bad mount, the engine literally jumps several inches immediately when you give it the gas instead of slowly stretching the mount.

 

check the transmission or the drive axle