The other day I noticed a vibration and clicking noises from the car. I am not 100% sure what it is but this is what I noticed today after a test drive.

1. 35 mph or faster a vibration throughout the car. You let up off the throttle vibration goes away you apply the throttle again still above 35 mph vibration comes back.

2. Shift into R and D results in a click like pop

3. Yesterday while coasting it was multiple click like pops without the throttle applied.

I am thinking U-joints are going out and the front one I noticed today has a zerk fitting which I havent greased since I had the car (2006) but its in such a place I cant tell if the grease gun got a positive clip on the zerk and I was able to get grease into the joint before driving. The rear joint at the 9" axle doesnt have a fitting.

Things ive checked is below

1. Engine mounts. No engine trq in drive with brakes applied hitting the throttle
2. driveshaft isnt loose no play
3. driveshaft weights still in place
4. front steering is tight minus the gearbox which always had slack in it.

I dont honestly think it can be the dampner up front cause there is no vibration in park applying the throttle its only when you are driving. And coming down the street it seems like there was a vibration while applying the throttle below 35 but I cant say for sure if that wasnt just my imagination.

 

Drive shaft u-joints, transmission tail shaft bushing worn; rear end pinion bearing getting sloppy.
Those would be where I would start looking.
Drop the drive shaft and check the u-joints first, the go from there.

 

I did grab the driveshaft with the transmission in park and tried to turn it back and forth for slop and couldnt get it to move at all. But I think I will do the U-joints anyways and check as you said the others. I know the rear U-joint hasnt been replaced theres no zerk fitting on it and friend of mine said he has always seen the rear U-joints go bad before the front driveshaft U-joints.

I am going to wait till I get a clear day to pull the driveshaft, I will replace both front and rear U-joints as well as media blast the rusty thing and paint. Hopefully its not the transmission or rear end and its just the U-joints.

 

A bad universal joint would get my vote also. You need to check them with the trans in neutral.

 

Ah I didnt do that. What would I be looking for in neutral? clicking sounds from the joint or just slack at the U-joint.

 

if they're bad when you pop it in nuetral and give it a twist you'll know . the shaft will "slop" in it . one of them suggested looking at your pinion too . had a vibration in my 53 and thats what it was . a million years of service and abuse and the ring and pinion were just a LITTLE worn .....................

 

I think for now I will put my bet on the U-joint since the rear one hasnt been replaced and has atleast 180,000 miles on it. I just need to find the time to check it. I just hope it isnt the ring and pinion the thing still drives great and smooth no bump when you stop and start to go again, ect. Its just this pesky click noise when shifting into reverse to back up then again into drive to go forward. Then theres the clicking from time to time when first starting to drive which goes away. But the vibration when on the throttle above 35 mph is the biggest bother to me.

 

Well I am more lost now than before.

I went ahead and picked up the rear U-joint. I got home and jacked the car up to get under it and put the transmission in N. The driveshaft wont even turn at all indicating slack in the U-joint at the rear axle. But yet now when you apply the throttle from time to time the vibration is there.

I am offically going back to the ford shop manual for this vehicle and see if it sheds any light on what it could be. I will still replace the rear U-joint that thing is bound to go out.

Well that doesnt help it just says that if vibration is above 40 mph its the tire balance. Um no its not that vibration comes in at 35+ and goes away when you let up off the throttle. Today how ever it didnt vibrate but once and that was when applying the throttle. So I dont know what it could be now. This shop manual isnt even worth the paper its printed on with the lack of "trouble shooting" in each section.

 

For all those that helped thanks.

I pulled the driveshaft and found out that hidden the rear U-joint had a cap that was snapped in two half of which was missing with zero roller bearings. Thats where the clicking sound came from when I would shift from Reverse into Drive. I went ahead and replaced the front and rear.

Only thing is I need to see where to send a complaint in for the autozone store I went to. I was extremly disastified with how I was told to leave when the ****tard wouldnt listen to me.

Told him rear U-joint for 78 mercury cougar. He said engine, I said 351. he selects 351 Modifed (was never an option for a 78 cougar just 351W or C). I told him the engine is a windsor he asked me again what the part was, I said a second time he has modified for the engine and this is a windsor. Finally he said what the part was a third time and growing tired of the arguing I just said the rear U-joints. He said what? and I was pissed off by then and raised my voice for everyone to hear "the rear U-joints for the driveshaft". He puffed out his chest like he was going to fight. He is glad he didnt since I would have pulled my knife on him for self defense. But he pointed at the door and told me to get out. i finally gave him the finger and told him that this store and directly his name will be mentioned in a report to autozone headquarters.

So looks like Autozone is off my list now just like Oreilly is for never going there again ever.