livharder

68 fastback. now this topic as been discussed a few times and i've read most of them but i need input from other members on this mysterious rear end problem. my car has a drive train vibration. (wheels are new, straight and rebalanced 3 times, bearings are changed, u-joints are new, drive shaft is balanced, changed axles.) when i put the car on jacks and make it spin to where my vibration starts, at 55+ mph, the wheels wobble in and out and a little up and down and the vibration seems to come from this wobble. this is where i need your input. remember i changed the axles with used ones and checked them for straightness. i make the car spin without the wheels on it and it's very difficult to see if there is a bent axle, i checked for the drum thickness backplate that could cause the wheel to be off when torqued. i checked everything and the wheels wobble quite a bit and i can feel te vibration in the hole car. but something even more intriguing is the mecanic that checked the car told me it was normal and he has also a 67 fastback and he when out to get his car to put it on the lift and his wheels are also wobbling. all this is very confussing. if by any chance you lift you car on a lift or jacks shortly please let me know if your wheels are also wobbling. i cant beleive these cars where wobbling that much when they were sold new. thanks in advance

Aussie66Fastback

IMO you need new axles.
i went thru the same thing with my 66 fastback. in the end i got a 9" but only because over here they were easier to get than axles and a new center for the 8".

the standard 8" axles are pretty much pathetic.

Gun Jam

You'll need to check for runout along the axle face where the drum would mount. use a dial indicator along the face and along the edge (both axises) .003 is about tolerable upper limits.

I had .011 and it would start to vibrate at about 55.

If you replaced junk with junk ...well you know the rest. You gotta check them with a dial indicator of some sort even at .011 the runout is nearly impossible to see with the unaided eye..a reference point is needed.

I had good luck replacing my stock axels with a set of "tom's kick *** axles"

happy hunting

-Gun

livharder

so what you guys are saying is, it's very possible that even my mecanic's 67 fastback also has bent axles and that the axle that i replaced from a old 9'' cougar diff is bent. so the all original axles have a very good chance to be bent or out of round after 42 years or so?

kalli

i'm with Gun, get a dialindicator and check for runout. up/down, in/out. 5 minute job and saves you a lot of headache