Car shakes over 70mph

[C.O.Jones]

Ok, I've narrowed it down to the driveshaft, or so I think. About 3000 miles ago I purchased and installed an aluminium driveshaft. Tonight I'm under the car trying to figure out the problem and I have 3 questions:

1) There's a bit of play (up down/side to side) where the yolk sits in the transmission. This I assume is no where normal?

2)By the same means, there's about 1 - 1 1/4" of exposed yolk between the transmission and the cap. Again, normal?

3) What the hell is fastened to the end of the transmission? I've noticed it before, but it was never any focus for attention. It appears to be an "L" shaped piece of metal with 2 rubber braces of some kind. I've heard that the Cat bolts to the Tranny for stability? My cat doesn't have any hangers on it, and it looks as though a piece of metal was removed from one of the rubber braces. Is this thing needed anymore?

[3.4 slow to go]

1. not sure, never checked when I was under the bird for that.

2. Normal

3. pics, need pics/

[C.O.Jones]

Ok, as far as #3 goes:
Did a little more digging and on stock Cats there's a hanger and bolts on the rear of the cat. These connect the cat to the brace on the transmission, so right now I have extra crap bolted to the transmission that I can remove. Ok, that's over.

#1 - Anyone else have this kind of play in the yolk?

[95Batmobile]

I think there is supposed to be a little, but I am not sure.

Have you thought about the free solution (usually free) and just go get your tires rotated and balanced? My car was shaking a little at 60mph, took it to get the tires rotated and balanced which was free and fixed it. Usually the place that mounts the tires will rotate and balance for free for the life of the tire.

BTW, you guys always call me "Bats" and I just noticed your sig...

[speedy-v6-camaro]

Is it your torque arm?

[Dominic]

When I had my tires roadforce-balanced my problems went away over 70. Try it. Find someone who does that near you, my Discount Tire did it for me $40. I thought it was my shaft too til I did that.

[Speed Freak]

Did you have the shaft balanced before install?

[silvachris1]

I was gonna sugguest tires too. They could be out of ballance, or one of them may even have a broken belt. Try rotating them (helped me), and if that doesn't solve it, try getting them ballanced. If that doesn't do it, put your old driveshaft back in. If that cures it, then you know the problem.

[C.O.Jones]

Originally posted by 95Battymobile:
I think there is supposed to be a little, but I am not sure.

Have you thought about the free solution (usually free) and just go get your tires rotated and balanced? My car was shaking a little at 60mph, took it to get the tires rotated and balanced which was free and fixed it. Usually the place that mounts the tires will rotate and balance for free for the life of the tire.

BTW, you guys always call me "Bats" and I just noticed your sig...

Thanks guys. Just replaced two VERY worn tires, and had them rotated/balanced. Don't know the full results yet (nowhere to go over 70) but they seemed ok up to 60. We'll see tomorrow.