gumballer

Hey Guys
Ibought a 66 coupe GT. and there is bad vibration coming when i am driving at a constant speed or decelerating at around 35mph. The vibration goes when i accelerate but returns as soon as i ease off the throttle. I checked the uv joints and they seem fine and i took off the driveshaft today and i found some metal shavings in the gearbox side of the shaft on the spline.

I also noticed that when i turn the drive shaft only one wheel spins at the back. is this normal or are the two of them suppose to turn.

Also when i am here.do any of you have any tips for opening up the rear axle. How do u top it back up with oil afteri put it back together.

As you can guess im am a rookie and any help would be much appreciated.

Thanks guys

baddog671

Like most, only one wheel should spin. Unless you have a locking rear, then both will spin.

To refill it, justsquirt diff. oil through the fill hole. Once it's full enough that it starts rolling back out the hole, its full.

To inspect the insides of your diff., youll have to unbolt the driveshaft, pull your axles out atleast a few inches, and undo the 10(i think) bolts around the centersection and it should pull right out.

Dunno aboutthe vibrations...

restomod@16

#1 the reason only one wheel spins, its just the type of axle you have. It's called "Open".

#2 - It would be better if we knew what size axle we were dealing with. If u need help with determining the size of your axle check the FAQ.

gumballer

its a standard v8 rear end. and i cannot tell the differencebetween the 8 inch and 9 inch. what does the 8 inch refer to. maybe i can measure it

baddog671

If you have a "hump" or 2 little "dimples" on the backside of your centersection, its a 9". Most probably its an 8" though...

type of carrier, not axle..

gumballer

it doesnt have 2 dimples. its got a drain screw in the middle of the center section.

cmanf

Vibration can be as simple as a bad trans mount to clutch chatter and so on.
Start with the basics like you did with the ujoints.
Sounds nuts but I had a mustang that the rear ujoint wasnt big enough to sit properly in the yoke.
They just sit the caps in the right spot so the slack was side to side bad vibration just like you described.
It just banged back and forth, not telling what some other owners may have done.

BTW wait till you change the oil and forget to take the old gasket off and wind up with two on there thats a interesting situation to deal with lol.

gumballer

thanks
i will look forward to getting my hands dirty doing this job.