bad vibration at constant speed
 

1985 gsl-se. im getting a severe vibration when cruising at a steady speed. it will start at about 30mph and occur at any speed above that. im thinking its the tranny mount. it occurs at any rpm and any gear. also if im cruising and let off it stops instantly and will start instantly when i apply just enough throttle. driving to nh in a couple weeks and just want whats best for my fb

Could be a mount but i'm guessing it's a dry worn out u joint .

My girlfriends car did the same thing except it happened at 90km/h (55mph) and above.
It ended up being a damaged tire it was all deformed on the inside and caused the whole car to shake.

Hope this helps.

sounds like a ujoint to me

Thanks for the replies hopefully il have some time to get it on a lift at work and check it out. Could a u joint be bad even if there isn't any play in it? Also can I get the u joint at a parts store or do I need a new driveshaft I herd there non serviceable

i'd start with the easy things , Like checking to see if you have any loose wheels , My friend had loose wheel nuts and caused this .

also it may be a wheel that lost its weights , could cause this as well .

check your tires for bumps or things lodged in it ..

then go for the U joint . it could also be alignment .

Yes they can feel tight and not be worn out so to speak but full of rust etc seized up. Just check them and then you know if you need to go further with them. It will give you the opportunity to check lots of under vehicle things while you are at it .
I've also heard that the u joints can't be replaced but I believe that they can be ,..

had the same problem , and it was my u joint on input shaft

Yup you guys know your stuff. It was the u joint on the transmission side. Tons of free play in it. I herd some driveshaft shops can remove the non replaceable u joints and put in replacable ones. Is this worth it or should I go with a new shaft. Kinda in a time restraint. I'm going to call around tomorow to get some prices

anything is possible, and im sure replacement ujoints arent out of the question. do them both while you have the driveshaft out. im glad you found your problem:icon_tup:

A new shaft is going to hurt I would check into replacing the u joints I think all they do is press them out . not sure never had it done . I guess if you can find a used one with good stuff it would be ok but you don't know what you are getting when you buy that sort of thing . but if you check the ends out it might be ok :) Gerald m.

I have had u joints cut off with a oxy acetylene cutter then welded the new ones back in. Anything is replacable if you have the right equipment.

I have done that too but I don't think we are suppose to tell anyone.. HEY LOOK THERE GOES A RABBIT !!