Jeff, Materials needed: Angle finder (digital preferred) 1. Go to http://www.4xshaft.com/index.html 2. Click on "Geometry 101"3. Scroll down to the second diagram entitled "Proper Geometry for Conventional Two Joint Driveshaft"
This diagram serves as a starting point. From here you may need to tweak a little depending on your driving style and Torque / HP numbers. If you just have a driver, maybe just get on it once in a while, and are just trying to get rid of vibrations, I would drop the rear pinion angle ONE - two degrees from parallel as shown in the diagram. This is done to account for the upward rotation of the pinion from leaf spring flex under acceleration. If you were drag racing all the time, you'd want to go lower...
So basically you need to measure the angle of the transmission output shaft and the rear pinion to see where you are at. This needs to be done with the suspension loaded and at ride height. I usually put the jackstands under the rear axle tubes and put my front wheels on wooden blocks. I bounce the car a few times before getting under to measure. You may want to also put jackstands under the front subframes near-but-not-touching for safety.
If you can find a flat, machined surface on the yokes to measure from, you're in luck. I use machined metal height blocks to space the angle finder out sometimes when there is interference with the tranny case or drive shaft. Make sure measuring surfaces are square and parallel to the ground and measure. I use a digital angle-finder accurate to .1 degrees (Home Depot) because I have had two supposedly nice manual angle finders and the needles are sticky enough to not be sensitive to 1 or 2 degrees, which is what you need it to be.
If you can't find a flat machined surface to measure from on either of the yokes, you will need to remove the driveshaft and take measurements off of the trans output shaft and the face of the rearend yoke. Again, make sure all measurements are square and parallel to the measuring surface / ground or they'll be wrong. Use a right-angle square held against the surfaces if necessary to fit your angle finder in there.
Now check the two angles against each other as shown in the diagram and see where you stand. Add shims angled forward or reversed under your spring packs to achieve the target mentioned above. I'd get longer spring bolts when you order shims, sometimes you need them and sometimes you don't. But you want to have 'em on hand when you do the job in case.
It is very straightforward, let me know if you have questions. Wakeman----- Original Message ----- From: "Jeff Adams" <ledman_70@xxxxxxxxxxx>
To: <1962to1965mopars@xxxxxxxxxx> Sent: Thursday, March 19, 2009 11:07 AM Subject: RE: Balanced flywheel
I think you guys are on to something here. Can anyone e-splain the procedure for checking the angle to me? Talk slow, cause my wife says I'm not the sharpest knife in the drawer! Dan McCormack wrote:Pinion angle is the first thing that came to my mind too Jeff. Especially after you said the engine idles and revs up smooth. A friend of mine was just telling me last night about a 64 Plymouth wagon that his Dad bought new and had a vibration in it. After many trips back to the dealer they discovered the pinion angle was off right from the factory. Dan----- Original Message ----- From: "Jeff Adams" <ledman_70@xxxxxxxxxxx>To: <1962to1965mopars@xxxxxxxxxx> Sent: Thursday, March 19, 2009 8:32 AM Subject: RE: Balanced flywheel > > That's something I never thought about...the car IS raised a few inches > in the rear, but not radically. I will check that asap, thanks. > Wakeman Massie wrote: >> >> Did you check the rear pinion angle? It should be parallel to the >> trans.ouput and then pointing down a degree or two from there. I >> always >> have to mess with that via leaf spring shims to get the vibes to go >> away, >> particularly if the car is "up" gasser style or slammed low. >> >> Just an idea.. >> >> Wakeman >>>> ----- Original Message ----- >> From: "Jeff Adams" <ledman_70@xxxxxxxxxxx>>> To: <1962to1965mopars@xxxxxxxxxx> >> Sent: Wednesday, March 18, 2009 2:47 PM >> Subject: Balanced flywheel >> >> >> > >> > I need some suggestions. I swapped a 413 4-spd into my 64 Polara 5 >> > years>> > ago in place of a Poly/pushbutton. There was a minor vibration, so >> > over>> > the last few years I have changed motors, 4-spds, rear ends, 3 >> > different>> > sets if tires/wheels, 2 different driveshafts, the current one >> > having >> > been rebuilt and balanced, the front end's been rebuilt and >> > converted>> > to >> > discs. I STILL have the vibration! The only parts that have not been >> > changed are the bellhousing and flywheel. AFAIK bigblock flywheels >> > aren't balanced...correct? The 426 wedge in it now runs smooth at an >> > idle and revving in the garage. I don't know where else to >> > troubleshoot. >> > Anybody have any other ideas??? >> > >> > Jeff Adams >> > 64 PolaraJeff Adams 64 Polara ----Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks!'62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.
---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines:http://www.1962to1965mopar.ornocar.org/mletiq.html.
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