66 F85 vibration
May 3rd, 2012, 03:15 PM
#1
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Join Date: Jan 2008
Location: Longmont CO
Posts: 39
66 F85 vibration
My sons 66 F85 has developed a vibration; I am headed up this weekend to have a look and hopefully fix it. He lives in another town at the university, so I cannot easily crawl under to see how much of a job either of these might be, and I am hoping you can help.
The car is stock and has the 330 with the 2-speed tranny.
Based on his description we have diagnosed it as possibly the torque converter being loose, or u-joints needing replacement, so we will be looking at both of those things.
Are the torque converter-to-flex plate bolts easily accessible? Hopefully there is simply a cover that is easily removed and then the bolts can be accessed by rotating the engine/tranny as needed.
On the u-joints I am hoping the grab the driveshaft and wiggle it routine might help diagnose. Is there a better way? What is the u-joint arrangement? I am not sure how they are held in place straps? Or are they pressed in? How difficult will it be to remove the shaft from the car them if that seems the next best thing to do (in order to replace the joints)?
Thanks.
The car is stock and has the 330 with the 2-speed tranny.
Based on his description we have diagnosed it as possibly the torque converter being loose, or u-joints needing replacement, so we will be looking at both of those things.
Are the torque converter-to-flex plate bolts easily accessible? Hopefully there is simply a cover that is easily removed and then the bolts can be accessed by rotating the engine/tranny as needed.
On the u-joints I am hoping the grab the driveshaft and wiggle it routine might help diagnose. Is there a better way? What is the u-joint arrangement? I am not sure how they are held in place straps? Or are they pressed in? How difficult will it be to remove the shaft from the car them if that seems the next best thing to do (in order to replace the joints)?
Thanks.
May 3rd, 2012, 03:37 PM
#2
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Join Date: Feb 2012
Location: billings mt
Posts: 44
the wiggle trick works good for me, just make sure the car is in neutral when you do it. if there is tension against the u joint from the weight of the car, you wont get as much wiggle as is really there.
my 67 needs u joints, and my symptoms are an all over vibration above 60 mph. tires and wheels are new and good.
my 67 needs u joints, and my symptoms are an all over vibration above 60 mph. tires and wheels are new and good.
May 3rd, 2012, 04:02 PM
#3
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Join Date: Aug 2011
Posts: 3,033
Loose torque converter bolts usually make a knocking sound often mistaken as a bad crankshaft bearing. They can usually be identified if you hear the knock when turning the engine off during the 2-3 seconds it turns before it fully comes to rest/stops.
If the vibration is driveshaft related it should be vehicle speed related not engine RPM, in other words 25 MPH in first gear should give almost exactly the same vibration as 25 MPH in second gear if it is a driveshaft problem.
If you are working on the driveshaft on the ground CHOCK! the wheels. When you remove the shaft you have disconnected the "Park system" and are relying solely on the parking brake, this is not sufficient and the car may roll while you are under it. CHOCK! the wheels.
Hope this helps.
If the vibration is driveshaft related it should be vehicle speed related not engine RPM, in other words 25 MPH in first gear should give almost exactly the same vibration as 25 MPH in second gear if it is a driveshaft problem.
If you are working on the driveshaft on the ground CHOCK! the wheels. When you remove the shaft you have disconnected the "Park system" and are relying solely on the parking brake, this is not sufficient and the car may roll while you are under it. CHOCK! the wheels.
Hope this helps.
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