Need advice, MOTOR MOUNTS - drivetrain vibration

DJ; one other thing. It will vibrate and clunk if the bushings in the rear springs are worn out. Also, recheck the engine mounts. If the engine torques up that far, one or both are probably bad, even if they are relatively new. Give it a look!

 

could your driveshaft have lost one of it's balence weights? inspect and look for a spot where something was tackwelded on but isn't anymore. also a buddy had some bad clunking and rattleing (sounded like motor was blowing) turned out to be loose nuts that attach torq-converter to flex-plate. I think spec is 25 ft/lbs. there should be a little acess plate at bottom of bellhousing. turn crank (clockwise-tighten) do one bolt, repeat. should be 4 bolts. maybe tire threw a balence weight. should be shadow of where it was. look on inside and outside sidewalls. I suspose ya looked for things like cracked/broken leafsprings? seen that before. is the crossmemeber @ back of tranny securly attached to the frame of the car. are all 3 motor/tranny mounts tight to everything they hook to? what about the brackets that attach the motormounts to the frame. ya said u-joints are ok. are there any spots where they "hang-up", do they have full smooth motion. check this with driveshaft out of car. while driveshaft is out you can check for broken diff, grab yoke that goes into differential and try to rotate(tires on ground) should be some play but not alot (??1/4, 1/2?? stop to stop)(ya'll corect me if wrong that might be bougus)

just a few thoughts, best of luck.
sorry about the jumbled thought process

 

1. triple-check those universal joints.....absolutely ZERO play allowed, and they should pivot smoothly in all directions.

2. with the car supported with stands under the rear diff (careful here). run the car in gear and see if the driveshaft spins true or eccentric....it may have gotten tweaked when the motor 'twisted up' way back when. or the driveshaft may need to be rotated 180' in the differential yoke.

good luck, DM

 

when i first got my mav it had a noise like that,it turned out to be the transmission mounts

 

Sounds like you may have a bad pinion bearing/axle bearing.If the noise is louder when you coast than when you are at cruise speed suspect the pinion bearings.If its the opposit suspect excessive backlash in the gears.If it dont change at all,could be axle bearings.Definitely check the stuff everyone has pointed out.The above repairs require some specialized tools and know how.Hey may be your opportunity to put some gears and a new posi in it!!!Hope this helps.Good luck.

 

this thread was started...5/5/14...

... ...

 

Yeah noticed after posting.Oops

 

it would be nice if they would let us know what they found .

... ...

 

Yeah I hate cliff hangers.