Vibration,,thinking out loud (update)

Interesting path that included finding the bad u-joint, at the rear.
Wondered if difficult pulsed-turning resistance possibly caused by a bad joint would
resonate, or damage/loosen another component. And in which direction,
fore or aft?

 

Update,,I replaced the U Joints with new Moog replacement parts and thought that would be my answer,,,after a test drive I still had the same vibration,,in fact it seemed a little worse.


I was out of town last weekend at the Good-guys show in Charlotte,N.C. so the car just sat,,I was convinced that my trouble was centered around the transmission or maybe clutch/pressure plate related.

Monday I put in a call to my friend Chris that has been in the transmission business all his life and due to the fact his shop is close to 30 miles from my house and me not being sure what my problem is/was he thought it best to drive over one evening and go for a ride.

He ask all the normal questions on the phone,,,,anyway he showed up last night and we took the car for a spin and ran through all the gears,,,his response was it defiantly is not the transmission or the clutch/pressure plate.

Chris said he had ran into this before with straight drive cars and before we were back in the shop he said I bet you have a broken motor mount and one of the heavy rivets that holds the rubber in place is probably making contact with the frame causing the heavy vibration.

He crawled under the car with a flashlight and sure enough I do have a broken motor mount!

So, today I ordered 2 new motor mounts and will try to get them installed over the weekend,,I have the engine up high enough to get the old mounts off,,just waiting for the mounts to come in tomorrow.

I will post the results after they are in,,I'm hoping this will cure the problem. HRP

 

Ive heard horror stories about Chinese motor mounts .... do you think that was the case with your old one ... chinese?

 

Hoping that does it for you, HRP. Kind of serendeputydog that the broken motor mount prompted you to find and replace the bad u-joint.

 

Glad you found the problem. Just wanted to add that a good way to diagnose these kinds of things is to jack up the car and run it through the gears. This method must be done with extreme care and safety precautions, but it works.

I had an OT car that was transmitting noises & vibrations through the floor at speed. Turned out to be a stone jammed on top of the trans mount (couldn't see it) in such a way that the rubber didn't isolate the sound. Took me weeks to find it after diagnosing every possibility you can think of.

 

Thanks for sharing. It's stuff like that can drive you mad!

 

I picked up the motor mounts today,took them out of the box and they don't fit,,Dammit!

I jumped in the truck and went back to the parts house along with my old mounts,,,they are correct part number and don't come close to matching the mount.

The parts guy,James takes one look and says I know what the problem is,,Ford used some left over 83 mounts in 84,,seems like I have that combination,the good think about James is he said he couldn't get the mounts until Tuesday so he called his compe***or and they can have them tomorrow (Sunday),,he got them to match the discount price he gives me and hopefully we will get them in and have the wagon back on the road tomorrow. HRP

 

Interesting thread. First we learn something about drivetrain vibrations, then we learn Hotrodprimer has an outstanding resource in "James the parts guy". We hear a lot of complaints about disinterested, ignorant parts guys. It's nice to hear that there are still good parts guys out there.

 

I picked up the new motor mounts today,,the new ones don't go back in place as ease as the old ones came out,,I had to remove the exhaust on the p***enger side to get the mount on.

It took a lot longer than I expected but the new mounts are in.

Test drive proved Chris was wrong,,the new mounts seemed to exasperate the problems,,,btw,, I started hearing metallic sounds and the heavy vibration was evident in all gears as I drove back into the neighborhood and up the driveway,,,damn,damn,damn! HRP

 

Sorry to hear it !

The wife and I were looking forward to seeing the wagon next Saturday.
Oh well ...

You still have a pair of Deuces to choose from

 

I've checked everything I can think of,I guess it's time to pull the transmission and hope I have a clutch/pressure plate problem,,as long as the transmission is out I'll take it to Chris and let him check it out. HRP

 

Yikes! The plot thickens! Great to have James who knows his stuff onboard.
Let us know, we're on edge here.

 

long shot... but it happened to a buddy of mine once.... check and make sure that the rear did not spin on the spring perchs,,,,, happened to a pal drove him nuts had the trans done once and out twice before he noticed the welds on the pads broke and spun the rear

 

Thanks for the thought Ron,,that was something I though of early on,,everything looks good with all the welds on the axle and springs. HRP

 

Before you pull the trans... think about those new symptoms, just from new mounts.

If the new mounts instantly made a change for the worse, it almost sounds like he was maybe right about something hitting someplace "like" a bad mount would allow.

In other words, if new mounts made it worse, right away, then why or how could it be something in the trans to get so much worse?


Trailer it over to him, to get him to test it again. I'll bet he knows how to feel/hear an issue when something in the motor/trans is hitting on something. He sounded so sure before, so I bet he heard that tell tale sound.


One more thing to try first. Get a driver, and then you ride along and hold your ear to the shift knob. If the trans is getting chewed up, you should hear it real clear.

 

You had the exhaust off and back on again also, maybe something is slightly different and now it bumps or something.
I know you're frustrated, and probably tired of the armchair troubleshooting....I'm off tomorrow, if you want another set of eyes and ears let me know, I'll try to help.
Good Luck!

 

Thanks buddy,,,I appreciate the offer but I gotta work tomorrow but I have decided to haul the car over to the transmission shop and let Chris have a go at it,,and you are right,,I am frustrated!

I removed the exhaust manifold,,not the exhaust,,I'm exhausted!

But like Deuce said,,I have something to drive so it's not the end of the world so we will take the sedan to Masons next Saturday,,,I just want to figure out what the problem is. HRP

 

dude check your fly wheel bolts ..i just had the same trouble happen to me to rebuild an entire motor to find out the bolts in the fly wheel had came loose and even lost a couple ..just check it even if you think its not it ...

 

Well that ****s! I thought you had it beat with the motor mounts.

 

Have you checked the harmonic balancer yet?

 

Yes,I looked at it and it's not loose,,that's all I know to check. HRP

 

It can slip around on it's rubber. Might want to check TDC just as a precaution.

Probably more likely something else.

 

I would think if it were the Harmonic Balancer, the gear it is in would be irrelevant

Also the fact that it got worse with the new motor mount just means that the ****ty old broken one was damping the noise and vibration more than a nice tight new one.
I'm going for a trans problem based on the 4th and 5th gear part of the equation - unless that is just putting more of a load on something. Try lugging it in 3rd and see if you get the same thing.

 

my guess would be something on the rear of the car. A bad u-joint and broken motor mounts sounds like symptoms of bad pinion angle. Either the rear end spun or something broke that changed the angle. I can't think of anything in any kind of transmission that would only cause a vibration in only 4th and 5th gears. Even a clutch wouldn't cause vibrations in only two gears.

 

If you read deeper in the thread it's vibrating in all gears now. HRP

 

I would agree, but with everything else checked it sounds like something engine related.

Wouldn't the direct drive of fourth and overdrive of fifth put more load on what ever is out of balance causing more noise?

 

No one has mentioned the muffler bearing. That has got to be it. If it persists, insert a small Chevy drivetrain. . I am sure you'll have it licked soon.

 

ok...........whats the scoop? where are we at lets get this figured out

 

kinda sounds like a t10 I broke where the tailshaft plugs into the pilotshaft, that small roller bearing held the shafts in alignment. wow, that was a long time ago.

 

OK,I know a lot of things it ain't,,the drive shaft is fine as is the universal joints( they have been replaced),the rear axle hasn't shifted or moved in any way,the harmonic balancer is fine and hasn't moved in any way,the motor mounts have been replaced,,,and Josh,,I checked the muffler bearing and its just the way it was from the factory!

The car vibrates like it's coming apart in all gears now and I'm hearing metal sounds clanking around.

I am taking the wagon to Chris (my transmission guy) the first of next week when he has a open bay and I can keep the car inside while we try to find the problem.

He has a lift that I can get the car up and pull the transmission,,we can check the clutch,pressure plate,throw out bearing and flywheel at that time.HRP