Re: pulsating driveline vibration?
[Re: stumpy]
#2651987
05/04/19 07:18 PM
05/04/19 07:18 PM
|
Joined: Jan 2003
Posts: 2,863 middle Tennessee
mopower440
OP
master
|
OP
master
Joined: Jan 2003
Posts: 2,863
middle Tennessee
|
Rear tire or driveshaft. Remove the drive shaft from the rear yoke and reinstall it 180* form where it was. Then run it again Not the tires because it still does it without the tires bolted up..Why would it just start doing this out of the blue though?
|
|
|
Re: pulsating driveline vibration?
[Re: BigBlockMopar]
#2652079
05/05/19 06:03 AM
05/05/19 06:03 AM
|
Joined: Aug 2007
Posts: 6,089 Valencia, España
NachoRT74
master
|
master
Joined: Aug 2007
Posts: 6,089
Valencia, España
|
I'm on same deal since EVER... My drive line goes something like RRRRRRrrrrrrrrrrrrrrrrrRRRRRRRRRrrrrrrrrrrrrrrrrrRRRRRRRRrrrrrrrrrrrrrRRRRRRRrrrrrrrrr and I can feel it just right down the center console. It begins to BE there from around 60 mph INCREASING up to the point the car becomes "undriveable" around 110-120 mph. At that speed it's not anymoure pulsating but constant and hard. My interiror rearview mirror shakes with it Things that have changed allong the years at diff stages ( not chasing the vibration but making upgrades on car )
-TC -Full rear axle: from open to SG, from 3.23 to 3.55, 1 axle, axle housing. -Drums -Wheels -Crossjoints ( including change the rear yoke on driveshaft from the 7260 to 7290 ) -Crankshaft / stroking my 400 ) -Flywheel.
and vibration is still there
Just left to check:
-Tranny master rebuilt kit just in case tail shaft housing bushings are worn -driveshaft itself ( althought once has being told it was good ) -instal the tranny tailshaft housing counterweight.
Last edited by NachoRT74; 05/05/19 06:06 AM.
With a Charger born in Chrysler assembly plant in Valencia, Venezuela
|
|
|
Re: pulsating driveline vibration?
[Re: RapidRobert]
#2652267
05/05/19 01:57 PM
05/05/19 01:57 PM
|
Joined: Jan 2003
Posts: 15,197 Omaha Ne
TJP
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 15,197
Omaha Ne
|
have either of you had the drive shafts checked for straightness and balance ? We have had more than one get bent by exhaust x pipes or crossover tubes when the rear end was allowed to hang. Not being able to feel it makes it difficult to diagnose. Tire balance, flat spots, separated belt ? Have them checked by a GOOD tire shop. My next check with a vibration like your describing is the drive shaft. Once that is known to be OK onto u joint angles, pinion bearings. One can check the RE housing to see if it feels excessively warm. A thought in closing: When a problem mysteriously appears think back to what you have changed / done. Many times you'll find the answer Keep us posted
|
|
|
Re: pulsating driveline vibration?
[Re: BigBlockMopar]
#2652292
05/05/19 03:09 PM
05/05/19 03:09 PM
|
Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
My Dart has this also has a bit of in and out 'phasing' rumble when cruising at the same speed at lower speeds. I had that once & it was the yoke was not far enough into the trans. I got the right shaft that was 1" longer & that took care of it.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: pulsating driveline vibration?
[Re: RapidRobert]
#2652344
05/05/19 06:03 PM
05/05/19 06:03 PM
|
Joined: Jan 2003
Posts: 2,863 middle Tennessee
mopower440
OP
master
|
OP
master
Joined: Jan 2003
Posts: 2,863
middle Tennessee
|
Update: Today i pulled the driveshaft only to find the u-joints are absolutely fine! Still just as smooth as the day i had them put in, no binding at all. I was hoping thats all it would be but no such luck. So i spun the pinion on the rear end and in turn, it spun the wheels, both forward (suregrip) and no noise. I had my grandson spin the wheels while i laid under the car where the rear end is and no unusual noise. So, i put the driveshaft back in, installed it 180 degrees off from where it was just to see if that would help. After i got the shaft bolted back in, i had my grandson spin the rear wheels again while i laid under the driveshaft and i could here a boom...boom..boom...boom coming from the tailshaft of the trans. So i scooted myself up under the tailshaft and had him keep spinning the wheels and sure enough, its coming from the tailshaft and i could slightly feel it in the tailshaft..So, im assuming this is where the problem is. Obviously he couldnt spin the wheels very fast but enough to make the pulsating boom and i guess when its spinning fast, it causes the bad vibration. I fired it up on the jackstands again and it seems to have kind of a slight vibration going all the time, but the pulsating bad vibration comes in about 40-45 MPH and way worse in 3rd gear than second..I can run it up to 45 in 2nd and its not near as bad as when it shifts into 3rd and at that same speed. I dont know much about transmissions so this really has me upset! when i bought this transmission, it was freshly rebuilt and when i got it, my friend tore into it to verify and it had been for sure. I bet i have not put 1000 miles on it since then, which has been around 2002 or so. It shifts fine and all, no slippage or anything. The ONLY thing i saw questionable when i pulled the driveshaft out was the shiny area on the front of the driveshaft that slides into the the transmission had some pitting going on and IF the tailshaft bearings used that shiny part of the driveshaft that slides into the trans as the inner race, then it would make sense as to this vibration being from the pitting..but i dont think its made like that..?
|
|
|
Re: pulsating driveline vibration?
[Re: Cab_Burge]
#2652594
05/06/19 12:36 PM
05/06/19 12:36 PM
|
Joined: Jan 2003
Posts: 20,645 So Near, Yet So Far
topside
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 20,645
So Near, Yet So Far
|
If you find the trans output bushing to be the problem, it seems logical to me that something caused the damage, which would lead me to question the yoke & driveshaft. Yoke engagement & spline condition, shaft imbalance, shaft runout. Reading through this thread again, I just recalled something: In '73 I ordered a Z28 and after it arrived, drove it a week or so before I noticed a rhythmic vibration. Took it to my local dealer and after a couple days they found a bent driveshaft, which they replaced under warranty. Why it wasn't immediately apparent when I picked up the car, I don't know. Another thing that pops up is how many times someone breaks a driveshaft at the track and the output area of the trans gets damaged.
|
|
|
Re: pulsating driveline vibration?
[Re: mopower440]
#2652773
05/06/19 09:56 PM
05/06/19 09:56 PM
|
Joined: Apr 2005
Posts: 279 pgh pa
captaindodge
enthusiast
|
enthusiast
Joined: Apr 2005
Posts: 279
pgh pa
|
[/quote] I would be suspicious of the transmission mount.[quote] So my suspicion might be correct. Maybe try a polyurethane trans mount to get that last little bit of vibration out.
Last edited by captaindodge; 05/13/19 11:46 AM.
|
|
|
Re: pulsating driveline vibration?
[Re: mopower440]
#2652793
05/06/19 10:46 PM
05/06/19 10:46 PM
|
Joined: Aug 2003
Posts: 43,007 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
|
Just to make sure that it only does this in gear, but not neutral Correct? Do me a favor and check the harmonic balancer to see if TDC is still at TDC
Last edited by Cab_Burge; 05/06/19 10:47 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
|
|