Hello I have a astro and I'm getting a bad vibration from the rear in between 45 an 65 mph I have had many people look at it they are just as confused as I am has anyone had this problem its a 94 with 328000 miles original engine trans and rear end as far as I know RWD 4.3 TBI

 

It could be Belts separating and or tire out of balance(maybe a weight fell off) in one of you rear tires??/ any noise ??/ it could be a dry or worn wheel barring, bad ring and pinion set up??/(Check low fluid levels) axles to spider gears all the after would probably bring on a noise??/ have some one clime in the back drive down the road if you can and listen and fell for vibrations ??/

 

I have new tires on it and it was inspected by the dealer they can't figure it out either

 

Can you feel the vibration in the steering wheel at all ??/ sometimes??/ all most all the time they will balance a drive shaft with weights!!/ They have been know to fall off ??/ they spot weld these little pieces of metal where ever the balance process tells them that it needs the weights,you can detect if a weight has fallen off by the remaining portion of the spot weld or by the discoloration of where the weight was as to the color of the rest of the drive shaft??/Have you changed any thing on your drive shaft lately( u-joints, slip spline, ect. ) with it out of the vehicle ??/ or when you had it at the dealer did they pull the axles ??/

 

Had the driveshaft balanced same issue someone said the over drive control module could be bad preventing it from going into it causing a vibration does that sound like a viable cause

 

Can you drive it down the road and tell if it shifts into all gears??/On mine (97 2 whl.) its hard to tell when it shifts ( Quite ), but if you listen real close you can tell if it shifts ??/ The transmission also has a lock up converter !!/ So your going to have 4 forward shifts plus the converter locking up,Which fells like a really smooth gear shift??/ The over drive control module's probable on the inside of the tranny right ??/ I'm not that fimilure with the 4L60E,Someone said that there a lot like the 700r4 (pan gasket ect.) A good transmission guy will pressure check the transmission (At shift points) with the rear wheels off the ground or on a dyno ??/ Might be the best way to go??/ I don't know what the cost is??/ you might try and fish some information from them over the phone before popping the cash??/ They have a transmission page at this webb site it might be worth your wild to post your <94 Astro Gladiator by Glaval Heavy rear vibration HELP> there ??/ There is a webb. site called AllExperts Questions & Answers that pretty knowledgeable and another one called eHow and at Summit racing there's Professor Overdrive. in contact's that's sometimes helpful??/ but I would post it here under transmissions here first!!/

 

Than man will do

 

Thanx man will do