Jack the car up and put it on four jackstands so the car is as near to level as it is on the road, run it up slowly in gear and identify what RPM and or speed the vibration is at. Remove the wheels and tires (make sure to either remove the brake drums and don't touch the brake pedal whie thier off ) and check it again. If the vibrations are still there look at the driveshaft, pinion angle and so on let us know what you find. BTW, Make sure the jack stands are under the rear end housing to test, not under the frame with the rear end hanging down on the springs and shackles

I know the pinion is the problem, I just said the floor, and my pinion are equal as a referance. The shaft basically is dead straight from trans to punkin. Its not good, and I know I need it corrected. Ill be busy in the morning, but I got to get it to Kearney for Reed Koeppe's flat landers fling this weekend.

Kasey

Well, I set my pinion angle 4* down from where it was, and I checked the ballance on the rear wheels, They were off by 2+ oz each. Still vibrates like crazy, I dont feel safe trying to make a maiden voyage down the strip with nast bad vibrations under power at high speeds, so Im just gonna trailer my car to Kearney to check out the cool Old scool cars there, and enjoy a stress free weekend.

Im starting to think I might have something in the tranny causing greef and racket, but I wont dig into that till I pull the engine for the stroker.

Thanks guys for all the sugestions, and help.

Kasey

OK, now Im just PIZZED beyond belief...

I just spent over 350 bucks, 370 after freight on a new ballenced drive shaft, and after pulling my hair out trying to find the vibration, I checked mounts, set pinion angle, ballenced wheels, checked brake drums, free revved the engine to 3800, you name it, I finally said to myself, I better check the only thing different. The driveshaft I just bought. ITS FREEKING WELDED 3/16 OUT OF ROUND ON THE FRONT YOKE!!!

Needless to say I wont be racing at all this weekend. I guess thats what I get when I order a shaft from a dirt track company who specialise in chevy style shafts.

When I got the thing, the front yoke felt funny, and had a catch in it. I noticed one of the caps wasnt pushed all the way in. I saw one of the snap rings was over the cap, not in the groove. Chevys are outside snap ring style, so If this guy is use to building these, I can see the possibility of it being wacko. But anyhow, I now know what happened. He probably had the yoke, and the ujoints together, WRONG, then tacked them up, but probably spun up the shaft before welding solid, and since one cap wasnt in correctly he compensated fo this by offsetting his yoke into the tube. If I wouldnt have inspected it, and ran it it wouls have been ok untill the u-joint flew appart.

I understand SH*T happens, but I really wanted to run my car this weekend...

Oh well.....

I can cruise for a bit, I still have heating issues to deal with too.

Kasey

Sorry the way things turned out for you this weekend. I wish you lived closer as I have several shafts laying around. Post the length you need and maybe someone can help out.

My shaft is 49.5", maybee couldnt hurt to be a snippy shorter, but I have 49.5 ". It has 7290 joints in it.

Kasey

Thanks!!!!

they did a good job balancing the driveshaft after building it

i would put it thru their front window

TRUST ME,,, Id love to.

Well I got the Demon up on the hoist today, got out my dial indicator and spin wheel tip, measured the tranny end. Its over .075" out of round. Thats terrible, and I can not believe this passed any quality control at all!!

Im very upset, and I really dont know If Im gonna have them build me a new one, or get my $$$ back and go strange, or mark williams.

Kasey

whered the shaft come from ?

Its a "FAST SHAFT" from a shop in Iowa. They are well known in the dirt car world, and my buddy has been flogging on one for years, and The race shop I bought mine from highly recomended mine. I on the other hand do not... I realize sh#t happens, but why me???

Kasey

Is it the drive shaft or the trans main out put shaft? u-joint? Hate to see you trashing somebody's product if it's not the problem. I had two out put shafts bent on two different transmissions. Could be that I drop the clutch at to low of rpm's

dennys is a better place to get one ..

Got my shaft back, Its only got the typical "im going 110mph in a 1971 model mopar" vibration now, but is smooth as silk at 60 through 80 on my speedo which is not accurate I have found out via state patrol.

The guys at Fast shafts were good to me, and said "sorry for the F up" and have a nice day. It still had anout .010 of run out in it, but That coud be a number of things with an old 833.

Kasey