Half Shaft's different OD

Reply Subscribe

Thread Tools

Search this Thread

Jan 16, 2015 | 09:24 PM

#21

cobrachuck

Pro

Joined: Mar 2006

Posts: 536

Likes: 87

From: SW Ohio

It could be the drive shaft or u joint when you replaced the trans sis you change the drive shaft?
When I bought my 67 GTO you could not go over 50 mph it felt like the back seat would vibrate out of the car. The u joints were not locked in place correctly.

Jan 19, 2015 | 10:16 AM

#22

byocum

Thread Starter

Advanced

Joined: Apr 2012

Posts: 55

Likes: 0

Quote:

Originally Posted by DUB

and also what I wrote in a the above post. But with not one reply from the original poster....we do not know if it is gone ore not.

DUB

I installed my rebuilt half shaft and the new one I had made. Both of them came back with weights from being ballanced. The drive shaft machinest quoted to me. That if it turns it needs balanced!! It doesn't matter how fast or what component it is. Unless it is designed to vibrate!!

Jan 19, 2015 | 10:41 AM

#23

Mike Ward

Race Director

Joined: Jul 2001

Posts: 15,892

Likes: 42

Quote:

Originally Posted by byocum

Of course he said that. He makes money on balancing things. I bet he'd say the same thing about the hour hand shaft on a clock.

Half shafts turn at about 600 RPM at highway speed. Driveshafts (at least twice as long) turn about 3 1/2 times as fast or more. Just look at your tach.

If your machinists says it's all the same thing........................

Jan 19, 2015 | 12:41 PM

#24

byocum

Thread Starter

Advanced

Joined: Apr 2012

Posts: 55

Likes: 0

Half shafts

Quote:

Originally Posted by DUB

and also what I wrote in a the above post. But with not one reply from the original poster....we do not know if it is gone ore not.

DUB

My car is still up on the blocks. Working on finishing touches now. Wrapping headers. Installing new radio ETC. I think the vibration was coming from bad bearing in the output shaft on the Muncie. It was definitely driveline related as there was no vibration when you revved engine with clutch pushed in. It got worse with speed. As I said before both half shafts were out of balance and required weights. I'll see if I can get pics posted of them. I guess we will never know where vibration is coming from if it's gone tho. As I've changed out to many variables at once.
Thx Byocum

Jan 19, 2015 | 06:57 PM

#25

76Rat

Racer

Joined: Jun 2013

Posts: 484

Likes: 43

From: NJ

Quote:

Originally Posted by Mike Ward

Of course he said that. He makes money on balancing things. I bet he'd say the same thing about the hour hand shaft on a clock.

Half shafts turn at about 600 RPM at highway speed. Driveshafts (at least twice as long) turn about 3 1/2 times as fast or more. Just look at your tach.

If your machinists says it's all the same thing........................

Highway speed (60mph) with half shaft spinning at 600rpm = 33.5 inch tall tire

We have a member who runs those tires.

Jan 19, 2015 | 07:22 PM

#26

Mike Ward

Race Director

Joined: Jul 2001

Posts: 15,892

Likes: 42

Quote:

Originally Posted by 76Rat

Highway speed (60mph) with half shaft spinning at 600rpm = 33.5 inch tall tire

You're right. It's closer to 735 with original size tires.

Feel better?

Jan 19, 2015 | 08:35 PM

#27

76Rat

Racer

Joined: Jun 2013

Posts: 484

Likes: 43

From: NJ

Quote:

Originally Posted by Mike Ward

You're right. It's closer to 735 with original size tires.

Feel better?

Yes I do, thank you.

Jan 19, 2015 | 09:47 PM

#28

Gale Banks 80'

Safety Car

Joined: Nov 2008

Posts: 3,717

Likes: 551

From: Seattle Washington

The good part is You have balanced them and now know that's not an issue whether or not its was an issue at all. It would be interesting to know how much weight was added or reduced. When ever You drive the car next if it still vibrates then what to do next ? If You think it was the same as before the Trans then I would start swapping Wheels. If You think it is something new since the Trans I would add or subtract shims at the cross member to change the driveshaft angle. Doesn't matter which way, just change the angle up or down to make it better or worse.