vibrations and axle

[Nacho-RT74]

Could an out of propper adjustment pinion and gear assembly on diff cause a HEAVY vibration ? I'm getting a HEAVY VIBRATION over 80 MPH that makes shakes EVERYTHING on car.

[flyinlow]

When did it start? Was the axle worked on? If you assembled the rear axle improperly I guess it could.

But first check for:

loose wheel,broken wheel , bad tire, wheel balance

loose u bolts on axle,broken spring

loose or improperly seated driveshaft, bent or out of balance driveshaft

[Nacho-RT74]

ok, firts I have to say that years ago, with my stock converter got same feelings but begining around 110 Mph

Found tranny mount was damaged too and got tranny began somehow to loose from block... dunno If I solved that when tighten everything and replace tranny mount because I barelly get that speed.

after years replaced also the crossjoint.

rebuilt tranny about 2 and a half years ago where my stock converted was replaced because gear ring was damaged ( I told for repair the gear ring ON MY EXISTANT converter, but no,THEY REPLACED my converter... noticed that just couple of months ago I got one with drain plug... mine was without plug... GRRRR )

6 months ago I got my suregrip unit and made the open carrier replacement and upgrade from 3:23 to 3:55 gears. Also changed the yoke on driveshaft from 7260 to 7290

Since this last upgrades I was getting a "Pulsating" vibrations begining around 70 Mph.

Recently changed the converter I had for a MP 166K one and had to weld the counterweights... Have to say one of the counterweights was welded around .050-.060 out of place...the other one maybe .010 out of place ( for a guy called like "tech" ). However on a recently thread I made asking about that Jhon Kunkel posted shouldn't be a headache or a problem

Mounting back the converter and tranny found flexplate was broken so installed a new one... AAAAAND the lower threaded holes on tranny to the lower bolts got stripped ( so will neeed to helicoil them )

Now I have what I explained.

[flyinlow]

I am guessing about 3000rpm at 70mph. Drive car at the same rpm in second and in first. does the vibration stay the same at the same rpm?

If yes ,check trans to engine bolts,torque converter bolts, motor mount,trans mount bolts or loose or out of balance accessory's.

If no, If you changed the companion flange on a 489 carrier and did not change the crush sleeve you might not have proper pinion preload causing noise. if you have a 742 carrier did you torque the pinion nut properly?

[Nacho-RT74]

honestly haven't check the RPMs when driving... will check.

I have the two lower bolts ( the ones what bolts to tranny ) some loosen because tranny threads are stripped. Need to fit helicoils

Flywheel related bolts are propperly tight ( crank and converter ) I'm sure on that!!!

will have to check preload on sleeve anyway ( yes is 489, but new crush sleeve )  because will need to check for pinion and ring play to save the "turbine" sound/noise... However I haven't noticed a leak on yoke seal to notice is moving and enlarging the seal... just at first times got some small leak not able to drop to floor, just running around housing... maybe because seal is leather and was getting seat on yoke.

when I meant changed the joke, I meant on driveshaft. My driveshaft had small joke end to axle end because I had 741 axle. Went to a driveshaft tech to upgrade to big joke when ugraded to 489/SG/7290 axle assembly.

will keep updated...


AS YOU CAN NOTICE I have small issues around what converts on a BIG ISSUE at the end

please buddies keep ideas coming.

there is another idea floating aroun now:
http://www.dodgecharger.com/forum/index.php/topic,51595.0.html

I think still can get a NOS balancing dampener around if needed.

[firefighter3931]

will have to check preload on sleeve anyway ( yes is 489, but new crush sleeve )  because will need to check for pinion and ring play to save the "turbine" sound/noise... However I haven't noticed a leak on yoke seal to notice is moving and enlarging the seal... just at first times got some small leak not able to drop to floor, just running around housing... maybe because seal is leather and was getting seat on yoke.

when I meant changed the joke, I meant on driveshaft. My driveshaft had small joke end to axle end because I had 741 axle. Went to a driveshaft tech to upgrade to big joke when ugraded to 489/SG/7290 axle assembly.

My guess is that your driveshaft is out of balance....try to isolate the vibration at different speeds in different gears like flyinglow suggested. See if it's speed related or if it does it in every gear. 

The whining noise in the rear end is most likely backlash. When replacing the crush sleeve with a solid spacer it's important to use the supplied shims to set the correct pre-load backlash. 


Ron

[flyinlow]

If you r vibration occurs at about 70 mph in drive and about 45mph in second and about 25-30 in first gear the problem is in the engine,converter,front parts of transmission or accessory.(same engine speed,but differrent drivetrain and tire speed)

If the vibration is only at or above 70mph. Could be transmission tailshaft(rare), driveshaft,axle ,suspension or tire/wheel problem.

Ron suggested the driveshaft. Check for :

damage

mud or grease buildup on shaft

rusted out

bent

loose /improperly seated in companion flange

worn u joints


Cheap ideas:

reseat driveshaft 180 degrees and test drive

take 3 or 4 wormgear clamps and install them with the heads together on the shaft ,test drive, try different clock positions on the shaft, test drive
experiment with the driveshaft balance this way . Does not cost much.

[Lifsgrt]

I looked in the manual for driveshaft runout to check for a bent driveshaft.  There is no spec I could find.  Anyone?

[Mick70RR]

I had a vibration that started about 70mph, was bad at 75mph and went away at 80mph. Tried everything but it turned out the tyres were out of balance, when I fitted 4 new tyres it was gone.

[Lifsgrt]

I have a vibration that (with 3:23 gears) begins about 105 MPH and just gets worse as the speed increases.  My driveshaft has about .035" runout at the midpoint.  The third member is fresh with new bearings, axles have new bearings and are correctly adjusted. Tires are good and balance is good (rotation with the front tires makes no difference in vibration).  I think maybe the transmission output shaft bushing is worn excessively.  Any thoughts?   

[Nacho-RT74]

I have been busy to make the checks... will update later. Want to fix the backslash I know have on my 3rd member assembly for sure, and will began again checking the origin