Vibration

Probably going to be a drive line or rear end issue. Proceed with the above mentioned tests.

Dave


As moparnutcase has noted, a drive line that is too long can cause significant vibration by resonating against the tail shaft of the transmission and the rear end yoke. Try taking the 4 bolts out of the rear u-joint, the drive line should move forward enough to easily clear the rear yoke. If it is bound up tight, the drive line is too long and is likely the source of your problem.

Dave
 
Check that the wheels are tight. Also check that the lug nut seats aren't wallered out.
 
As moparnutcase has noted, a drive line that is too long can cause significant vibration by resonating against the tail shaft of the transmission and the rear end yoke.

Dave, just to clarify....drive shaft being too long could be an issue, however, I stated that my problem was the drive shaft was too SHORT and was slapping around in the tail shaft.
 
Thanks for all the good ideas but the problem is finding a shop/someone knows what they are doing. That is going to be a task in itself! Unfortunately, I can no longer physically do this type of work. First they diced me, then they marinated me and then they cooked me!
 
that truly sucks. hope someone recommends someone in your area. i am a thousand miles away. good luck. please let us know when and what you find.
 
If you pull the driveshaft run the car in gear looking in the rear of the transmission to see if the mainshaft wobbles alot. I have seen a trans mainshaft bent.
 
If you pull the driveshaft run the car in gear looking in the rear of the transmission to see if the mainshaft wobbles alot. I have seen a trans mainshaft bent.
It vibrated before the tranny rebuilt and vibrated after the rebuild so I doubt that is the issue but thanks!
 
It vibrated before the tranny rebuilt and vibrated after the rebuild so I doubt that is the issue but thanks!
Yes but checking the mainshaft for a bend or replacing it is not normally done in a rebuild. It is also very easy to see with driveshaft out.
 
I agree w/ Big Block Dodge on checking output shaft run out. Bearings and tail shaft bushings are usually the most likely culprits. One that is missed on occasionally is the front driveshaft yoke. The yoke will wobble on the out put shaft and bushings and bearings get the blame. Have had many cars brought to me w/ rebuilt drive shafts w/ the complaint of like yours only to find multiple problems including a worn driveshaft yoke.
 
Just curious, with all this mentioning about the driveshaft, and that is were the u-joints changed out? I know a friend of mine, in the Cougar Club, sold off his yellow Cougar after endlessly trying to diagnose a vibration. He did buy another nice one later. The person who bought it, told me at one club meeting, that the problem with his car was an incorrect joint and once replaced all was fine. Just thinking as the incorrect joint was put in by the shop since the owner doesn't have that mechanical ability.
 
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lets just leave mudeblue alone for a bit till he absorbs all of the great info introduced to him. i would be racking my head against a wall. just my thought. i am sure he will keep us up to speed.
 
Just curious, with all this mentioning about the driveshaft, and that is were the u-joints changed out? I know a friend of mine, in the Cougar Club, sold off his yellow Cougar after endlessly trying to diagnose a vibration. He did buy another nice one later. The person who bought it, told me at one club meeting, that the problem with his car was an incorrect joint and once replaced all was fine. Just thinking as the incorrect joint was put in by the shop since the owner doesn't have that mechanical ability.
Incorrect u-joints installed do happen. Chinese made u-joints quality problems are common. Easy to diagnose. I agree w/ tbm3fan.
 
Incorrect u-joints installed do happen. Chinese made u-joints quality problems are common. Easy to diagnose. I agree w/ tbm3fan.
I would be suspect of driveshaft since any yoke issue I have ever seen results in new yoke being welded on. Fixing a driveshaft without new yokes is like me fixing it on the floor of my shop with a hammer. The last driveshaft I cut and shortened at home has a dent.in the side from forks of high lift that put the car on and off trailers at scrap yard and runs 80mph with no vibe. That driveshaft and it's u joints are suspect.
 
A couple things... but a good shop should pick up on them. Check the pinion angle, especially if the springs have been changed, or if it has old saggy ones still. Also, the slip yoke could be wasted from previous use before you got the car. This would be a slip yoke being a 65, not a ball and trunion right?? I saw a problem with a ball and trunion once that was just an overabundance of grease and the problem would go away after it slung a bunch out (over 70mph driveline vibration) Good luck with it.
 
Updat
1965 Sport Fury - Have a chronic vibration for several years sometimes slightly at low speeds which disappears between 30 - 75. At 70 and up, terrible vibration and have to reduce speed. Can't identify exact source.

Over the years, I have had the transmission rebuilt5, which was relooked at, straightened the drive shaft, which repair shop said was bent, replaced both back axles which again two different repair shops claimed were bent on different occasions and I just had different rims and brand new tires put on car, yesterday. Even had the motor mounts checked along the way.

I am now at the point that there might be a possibility that I may have a fly wheel or torque converter out of balance. However, this should have been identified during the transmission rebuild and recheck.

I am lost and would appreciate any ideas.
Update: Have all four new rims, new tires, driveshaft was bent and straightened (again, second time???), new universal joints, new axels which corrected 80% of my vibration problems at 3,000 RPM's when driving but still have noticeable vibration. I was told the "transmission mount" needs replacing but shop could not locate one here locally an told me to order and they would install.

If have gone to the internet and there it gets confusing. Some look a little different but the prices run from $6 and change to $150 and change. What am I missing? Any advice, pictures or part number would be very helpful so I order the right part>
 
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Take a pic of the cross member and the mount. I thinkI can help you.
Here is a picture. Sorry this is the best I can do because I can't get under the car.

IMG_4845.JPG
 
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