[Ivarkjerstad]

Hi, good folks.

I have a '68 Nova, 2-door coupe, and the other day I went to get it checked on the Dyno. A couple of minutes into the test, the guy who did the test refused to continue, due to vibrations from the drive shaft/propeller shaft. He said I should immidiately should take it off and send it to the local shop for balancing.

My plan was to do just that, but then I started asking around. Short story; the previous owner of the car changed the transmission, from automatic to a 4-speed manual. Due to this change, he had to weld on around 2.8 inches to the existing drive shaft. The welding is done in the front (next to the transmission). In addition, the front yoke and the rear yoke are not "lined up" to each other. Is looks like their off sync. I am no expert, but I would think that this is not helping the vibration around 50-60 mph. Anther friend of mine said I also should check the drive shaft angles, to check if they are "within" the limits. On the transmisision, on the drive shaft itself and on the rear end/axle. He said that is these angles are off, there is no point buying a new, cause I will just end of with the same problems.


Finally to my main questions:

1) Is there any point in sending the existing drive shaft to the local shop for balancing? Since it is old and has "homemade" welding done to it...? Mind you, the local shop is 7 hours by car away from where I live, so I can't just run by after work to get it checked.. We're talking weeks of waiting.

2) If I decide to get a new one, what's a good place to buy? I am thinking of an online shop, of course.. (since I live in Norway). A new one in Norway costs around 633 dollars... (estimate I was given).

3) What kind of measurements do the shop need to make me one? Right now I have only measured the distance from center front yoke to center rear yoke, and the distance is around 52.4 inches. I also have the distance between center front yoke to the end of the slip yoke, which is around 5.3 inches.

See attached photos to look at my existing drive shaft, to see the welding and position of the front/rear yoke.

I really appreciate all the help I can get! Thanks in advance to all the experienced people out there!

Ivar K, Trondheim, Norway

 

[71SS454]

Your homemade driveshaft is definitely "out of phase". I would highly recommend a new one. There's Denny's driveshafts, Mark William's, Strange engineering, Inland, Summit, Jegs, Speedway Motors, and many more. What you do for measurement is Jack the car up, but keep all the weight on the suspension. Insert the slip yoke all the way in then pull it back about an inch to an inch and a quarter, and measure the distance from the center of the front u-joint to the center of the rear u-joint.

 

[NCDEERE]

If he's good let your local guy build one. I have a shop three miles from me that drag races and builds shafts for all of the local racers. He built me a 1350 shaft using my front yoke MUCH cheaper than any mail order shop and said if I ever break it he will replace it free for life.

 

[Rick_L]

Two things about your current driveshaft. You don't lengthen a driveshaft, it will never be straight. And as already pointed out, the yokes must line up. I'm surprised the car was driveable even at low speed.

You've been given a pretty good list of online sources. Most will have instructions on their website on how to measure. Not everyone has you measure the same way.

By the time you pay freight and customs, the price for an online driveshaft shipped to Norway will be pretty close to your local estimate. Maybe even higher. So make your choice based on your confidence in the local source.