pinion angle set-up ('68 440 charger) UPDATE!!

[68n70]

Well we haven't solved RECHRGD's problem, just mine.  And since my car is a major DOG, no white smoker videos (although, I'm working on that with the help of firefighter!!)

[Runner]

bob, did you cut down your original drive shaft when you installed the gv?   have you thought that mabe is just the gv unit?     if the fibration is bad, right in the area that yoiu cruise at and it was fine prior to the gv, id put a stock tail shaft back on and just let that 440 eat at 70 mph.   nothin sucks more than chasing a problem likw this and spending buckets of cash on it and making no progresss.


     im going to try and make it to spokane the 16th and check out the new truck and see what my pig will run on it.

[RECHRGD]

bob, did you cut down your original drive shaft when you installed the gv?   have you thought that mabe is just the gv unit?     if the fibration is bad, right in the area that yoiu cruise at and it was fine prior to the gv, id put a stock tail shaft back on and just let that 440 eat at 70 mph.   nothin sucks more than chasing a problem likw this and spending buckets of cash on it and making no progresss.


     im going to try and make it to spokane the 16th and check out the new truck and see what my pig will run on it.

Hi Mike!  I'm going to play with the balance at the rear (pinion) of the driveshaft tomorrow as the G/V tech suggested.  I still have the original driveshaft and tailpiece but, after all the time and money I've put into this setup I'm not about to give up the ghost yet.  The G/V guy swears that there is nothing in the unit that could be causing the vibration and still is leaning toward something wacky in the driveshaft.  I'll let you know.  I'd like to go to the drags on the 16Th even if I don't take the car.  I did hammer it up to over 100mph with the new tranny the other day and it sure felt strong.  Bob

[mauve66]

Well we haven't solved RECHRGD's problem, just mine.  And since my car is a major DOG, no white smoker videos (although, I'm working on that with the help of firefighter!!)

CRAP, i was so excited i didn't even look at the postER

[RECHRGD]

Well, the pipe strap on the rear did nothing.  I'm thinking the next thing to try will be to yank out all the Schumacher Poly mounts for the engine and tranny, and replace them with the original factory units.  I remember when I started the car for the first time with the poly mounts that the engine vibration was much more noticeable.  This was about the time I was dealing with a score of issues with the car, so I cannot pinpoint exactly when the vibration at speed became an issue.  If this turns out to be the problem, I will not be a happy camper.  Those things were very spendy and are advertised to "prevent blow-outs while dampening vibrations transmitted from the chassis".  Bob

[roger440]

Once the vibration starts does it get worse as speed increases, or does it go away again?

Im inclined to agree that the G/V unit cant really cause the problem unless the output flange is not true.

I assume your pinion bearing is OK? no play? No play in the U/J's

I didn't really understand what you meant about spline engagement?

[mauve66]

when the pinion gear is install with the crush sleeve, the spacers/washers/what ever you call or yeah SHIMS, determine how far back the teeth of the pinion go into the ring gear, when the ring gear mesh you check it with a little white lithuim grease or similar and make sure the teeth engagement are centered front to back and side to side, promotes more even wear, i didn't know he had bought a new one before the GV unit.

i still contend that with the wheels off the ground and the drive shaft removed and no vibration at that point it has to be farther back since everything up front is still spinning like it thinks its doing 70 mph

[RECHRGD]

The rear pig was purchased from Randys Ring and Pinion several years ago and without tearing into it, all appears well.  It has the solid spacer rather than a crush sleeve.  The more I research this thing, the issue of the hard motor mounts keeps coming up.  Some pretty bazaar things can show up that don't really make much sense.  To answer roger 440's question--yes the vibration is gone by 80mph.  It's basically between 65 and 75.  Anyway, I bought the grade 8 bolts to put through the drivers side mount (per firefighter Ron) and will put the old mounts back in and see what happens.  Say a prayer for me.    Bob

[RECHRGD]

OK, I bought all new mounts and took out the three schumacher units.  As suspected the problem still exists.  However it is much less noticeable with the softer mounts.  In fact, in overdrive it is barely noticeable at all.  I'm tired of screwing with it and have opted to live with it until I feel like chasing it again.  It's time to get out and enjoy the car.  To top off this perfect storm of problems, the new mounts made the engine sit up a little higher.  With the RPM intake it was always very close as far as hood clearance was concerned.  Before today's project I had added a second air cleaner to carb gasket because of some fitment problems.  So, of course, I now have a fresh dent on my hood from the air cleaner wing nut.   Anybody have good luck with these paintless dent repair places?  I guess I better post that question in the proper section.  On the plus side, I was so pissed when I noticed the dent that I decided it would be a perfect time to perform a back road acceleration test.  I'll nailed it from a dead stop in drive and it fried the tires through 1st and 2nd until I had to get out of it at around 70mph.  So, I guess all the performance upgrades that Ron and Mike (runner) have been helping me with these last couple of years have done their job.  Now it's time for a couple of adult beverages.  Thanks for all your help and suggestions guys.      Bob

[firefighter3931]

Bob, sorry to hear about your hood. 

Try using a button head bolt instead of the wingnut and stud for better hood clearance. Sounds like it's performing much better than before. 


Ron

[Runner]

sorry to hear about the hood bob, i am glad its making good steam though

[roger440]

The rear pig was purchased from Randys Ring and Pinion several years ago and without tearing into it, all appears well.  It has the solid spacer rather than a crush sleeve.  The more I research this thing, the issue of the hard motor mounts keeps coming up.  Some pretty bazaar things can show up that don't really make much sense.  To answer roger 440's question--yes the vibration is gone by 80mph.  It's basically between 65 and 75.  Anyway, I bought the grade 8 bolts to put through the drivers side mount (per firefighter Ron) and will put the old mounts back in and see what happens.  Say a prayer for me.    Bob

If it goes away again, then its wheel balance or more likely driveshaft balance. I know you have done that already, but that is where your problem lies. Is it really running true?

[rcannon440]

Did RECHRGD every find a solution to the vibration problem? I am having the same problem with a A518 overdrive swap I did on my 69 Charger. I have even tried a different drive shaft different transmissions changed torque converter flex plate and checked pinion angles. And for no apparent reason sometimes the vibration is worse than other times. I'm trending towards the drive shaft.

[RECHRGD]

It all came back to the driveshaft balance.  Even with all the balancing and a different DS, the vibration remained.  I went back to the pipe clamp method of balancing the DS on the car.  I had the rear jacked up while on my Four post lift and spent all day clamping on different combinations of coins to the front and rear of the DS, then running to up to speed on the lift.  I was able to get rid of most of the vibration, but not all.  Although I've been living with it all this time, I'm about ready to go have an aluminum DS made and be done with it.

[Paul G]

Did RECHRGD every find a solution to the vibration problem? I am having the same problem with a A518 overdrive swap I did on my 69 Charger. I have even tried a different drive shaft different transmissions changed torque converter flex plate and checked pinion angles. And for no apparent reason sometimes the vibration is worse than other times. I'm trending towards the drive shaft.

Did you re use the yoke from the 727? Or get the correct A 518 yoke?

[rcannon440]

I thought both yokes are the same. It's the 727 yoke.

[Paul G]

That could cause vibration. The a518 output shaft is slightly smaller then the 727 out put shaft. The 727 yoke will slide in an a518, the a518 yoke won't slide in a 727. Get the a518 yoke and a lot of the vibe will go away.