Posted By: moparmikethree
Help!!! serious vibration - 04/12/10 02:20 AM
1970 Challenger , 360, 727 , 8 3/4
When going down the road , bad vibration at 45mph
and up. When putting in neutral , almost all goes away. Engine in neutral is very smooth. (all rpm's)
Trans is rebuilt, with weighted torque converter.
New trans mount. Drive shaft is balanced and new u-joints.
When unbolting driveshaft and pushing completely into trans , how much space should be at rear u-joint and rear yoke?
How can I tell if it is in the Rear end itself, bent axle, or if it is inside the trans??
Please help, Thanks Mike
Posted By: NITROUSN
Re: Help!!! serious vibration - 04/12/10 02:22 AM
What are your driveline angles?
Posted By: moparmikethree
Re: Help!!! serious vibration - 04/12/10 02:26 AM
Its been awhile since I checked them, If I recall it is 1 1/2 degrees down on rear end and 1 1/2 degrees up on trans. Not entirely sure but thats what I recall
Posted By: moparmikethree
Re: Help!!! serious vibration - 04/12/10 02:41 AM
This car was an original slant six/ 904, Converted over to a 360, 727, everything new (everything)
When accelerating it is really bad. Feels like a tremor starting at the firewall and traveling under the console the whole way back to the rear
Vibration gets better when slowing down
Posted By: NITROUSN
Re: Help!!! serious vibration - 04/12/10 02:45 AM
Sounds like incorrect pinion angle.
Posted By: RapidRobert
Re: Help!!! serious vibration - 04/12/10 02:52 AM
After the swap was it OK then it developed? W the trans mount/bolts good I'd open up the ujoints & check for any needle problems/looseness anywhere.
Posted By: Mopar1
Re: Help!!! serious vibration - 04/12/10 02:59 AM
Are the balance weights missing from the torque converter? Check the U-joints to see if they are centered in the yokes, if they are not they will bind and cause a bad vibration.
Posted By: moparmikethree
Re: Help!!! serious vibration - 04/12/10 03:16 AM
All u-joints are new, but I rechecked them, all needles are good , and u-joints are greased.
torque converter does have the weight on
Posted By: moparmikethree
Re: Help!!! serious vibration - 04/12/10 03:18 AM
when you disconnect the driveshaft and push completely in how much distance to the rear yoke?
Posted By: RapidRobert
Re: Help!!! serious vibration - 04/12/10 03:40 AM
Mike has it vibrated like this ever since the swap? My money is still on the driveshaft (angles/ujoints). On my 65 dart 318/904 I used a driveshaft that was too short and the yoke did not engage the tranny splines enough (way more than 3/4") and you could feel the play of the yoke on the splines as you slid it in and it vibrated mostly on decell but nothing like yours is. I found the correct shaft that was less than an inch longer & that solved it
Posted By: moparmikethree
Re: Help!!! serious vibration - 04/13/10 05:55 PM
Checked pinion angles with suspension loaded
as driving down road
Drive shaft angle is -2 degrees down towards rear
output shaft of trans is at 0 degrees
Rear end at flange is -3 degrees.
What is needed, do I have to lift the trans?
or change the rear end?
Posted By: moparmikethree
Re: Help!!! serious vibration - 04/13/10 05:56 PM
It has been there ever since the swap.
I had the tires road force balanced
Posted By: Dodgem
Re: Help!!! serious vibration - 04/13/10 07:11 PM
I've seen the weights come of the torque.
check and see if the u joints stayed centered may a clip is off??
Posted By: 318 Stroker
Re: Help!!! serious vibration - 04/13/10 07:22 PM
I had a similar problem with similar symptoms on my Challenger. Turns out that my brand new, and supposedly balanced driveshaft wasn't balanced at all...
Posted By: moparmikethree
Re: Help!!! serious vibration - 04/14/10 02:41 AM
weights are still on the torque,
What about the readings for the pinion angle