Warped flexplate? Videos, updated.

[Priceless]

Is the flex plate warped? OR is this normal? I had it removed a while ago (last year) and there were no cracks. The bolts are tight.

Im trying to track down a vibration at 35mph-50mph. Ive replaced just about everything that could cause it. Balljoints, u-joints, balanced driveshaft, shocks, wheels, etc..

The Torque converter is not hooked up in video.

Any help would be appreciated. Thanks..

Old flex plate



New Flex plate



New Flex plate connected



The vibration at 35 in the passenger seat. This is on a new paved road, very smooth and flat.



This is after the new flex plate. About the same before the replacement.



UPDATE:
After Talking with DaveP we figured it out. The pinion angle was way off. In order to fix the pinion angle I found the transmission mount had collapsed. The new transmission mount was about 1/4 inch higher. So far after 300+ miles the vibration has not returned.

 

[mattw]

Re: Warped flexplate?

Re: Warped flexplate?

I'm going to go with not normal.. I've always seen them spin good and true.. Any whining noise from the transmission or other signs that the torque converter may be ballooning?

 

[Priceless]

Re: Warped flexplate?

Re: Warped flexplate?

Torque converter was replaced about 800 miles ago due to it being bad. The torque converter i took out was small (10") and had a mid plate attached to it. It was making a grinding noise.

Ive installed a B&M converter and the noise is gone. Transmission shifts as it should. I just have a nasty vibration at 35mph, like something is out of balance.

The balancer has no wobble, so the crank should be fine... hopefully.

 

[graham1524]

Re: Warped flexplate?

Re: Warped flexplate?

Is the converter seated properly? theres a certain technique to it where it doesnt seat all the way in

 

[Priceless]

Re: Warped flexplate?

Re: Warped flexplate?

During the video the converter is not attached. I cant remember what the distance was between the flexplate and converter but it was less than 3/16.

The vibration i have was there with the old converter.

 

[Priceless]

Re: Warped flexplate? Videos, updated.

Updated with new videos, I still have the vibration.

 

[wildphil]

Re: Warped flexplate? Videos, updated.

When I got that Black Ty you used to own it vibrated quite a bit. I replaced everything in the suspension to try and get rid of it. Still had the issue.

I replaced the wheels and tires and it drove like new.

I can see that you have changed out the wheels. Are they stock SyTy rims? Did you replace the tires? I have been told you can remove the wheels from the car and find something strong enough. Like maybe a metal fence post. Run it through the hole in the wheel and spin the wheel to make sure it spins true. Never tried it. Just a idea.

Did you make sure your new flexplate was for a external balanced 4.3 engine?

 

[Priceless]

Re: Warped flexplate? Videos, updated.

Yup the flexplate is externally balanced. SFI certified. (If that means anything, just heavier duty)

The rims are Zr1 knockoffs. Brand new tires etc. I've had 3 different pair of rims/ tires on it with no difference.

All the shocks, brakes, front end suspension have been replaced. Driveshaft re-balanced with new u-joints. Its a really weird vibration as it does not occur all the time. But when it does, it feels like something is bent or out of wak. And only between 35-45mph. And it does not matter what gear or RPM it is. If its shaking, its shaking. I've down shifted to 2nd during the vibration and it stays the same. Does the same with out the prop shaft in to.

The vibration is felt in the seat of your pants. I do not feel it in the steering wheel at all.

The truck runs great and shifts great. If it wasn't for the vibration i would drive it a hell of a lot more.

Im starting to wonder if the cheap shocks on the back (Gabriel load assist with springs) has something to do with it.

 

[Peter]

Re: Warped flexplate? Videos, updated.

If it only correlates to road speed, not RPM, and it's in the seat of the pants, not steering wheel, a lot of stuff has been eliminated. You've tried three sets of tires and wheels. There's not much left except driveshaft and rear axle. Yes, bad shocks can amplify even a small vibration, so I would not rule that out. It could also be pinion angle. Do you have lowering blocks? Watching the back of the seat shake, though, I think it could be the shocks. Vibration from the pinion angle is a higher frequency than from tires. If you have a bad shock, a wheel can actually bounce along the road after hitting a bump, or if even slightly out of balance. That can really shake a car.

 

[IGottaSy]

Re: Warped flexplate? Videos, updated.

If it only correlates to road speed, not RPM, and it's in the seat of the pants, not steering wheel, a lot of stuff has been eliminated. You've tried three sets of tires and wheels. There's not much left except driveshaft and rear axle. Yes, bad shocks can amplify even a small vibration, so I would not rule that out. It could also be pinion angle. Do you have lowering blocks? Watching the back of the seat shake, though, I think it could be the shocks. Vibration from the pinion angle is a higher frequency than from tires. If you have a bad shock, a wheel can actually bounce along the road after hitting a bump, or if even slightly out of balance. That can really shake a car.

This^^^^^

My truck had some vibration and loud thumping noises that were due to incorrectly installed lowering blocks. Pinion angle and axle center were altered by the blocks. Driveshaft would bottom out against transfer case. Blocks are gone and so are the issues it had.

 

[Priceless]

Re: Warped flexplate? Videos, updated.

Bought some cheap shocks. Still the same vibration. Rides softer though.

Ill remove the lowering blocks tomorrow. Gonna look weird with the coilovers up front.

Wish JSM had the 3-link kit available. Something I'm waiting for.

***One thing i did notice is the shim plates on the rear leaf are on the bottom. (Original location not moved) The blocks are the adjustable AFCO ones.

 

[Priceless]

Re: Warped flexplate? Videos, updated.

Little update.

I took the rear blocks out and it made no difference. (Pinion angle shim still installed)
I raised the front to stock height, still no difference.

So i gave up and took it to a mechanic. They thought it was a tire, so they balanced the tires. No difference.
They said the suspension looks fine and the tires/rims are fine. Alignment was within spec. They couldn't figure it out. Luckily since they couldn't figure the problem out i didn't have to pay.

So I put the truck on blocks and wanted to check to see if the rear axles might be bent. The axles appear to be straight since I don't see any wobble in the tires/rims or the rotors. But I can definitely tell the vibration is coming from the rear. Looks as if the Pinion bearing might be lose or going bad. I had my wife give the truck gas as i watched and I can see the rear shaking. My wife said she can feel it through the seat.

Anyone ever had a pinion bearing go bad? Any other ideas?

Thanks again for everyone's help.

 

[Priceless]

Re: Warped flexplate? Videos, updated.

Heres some videos of the pinion and the axles.

Pinion



Driver side axle



Passenger side axle




Are those axles normal? They don't look bent but they are definitively out of round. The wheel bearings have a little play in them, but not much. And the pinion does not move at all, just looks weird in the video.

 

[liquidswords88]

Re: Warped flexplate? Videos, updated.

Pull the rear driveshaft and run it with all four tires off the ground. You could also have a bad u-joint. You would hear the joint squeak long before it would cause a bad vibration. When the rear driveshaft is off check both u-joints. If the pinion was loose enough to cause a bad vibration, the rear end would be making noise.

 

[Priceless]

Re: Warped flexplate? Videos, updated.

Pull the rear driveshaft and run it with all four tires off the ground. You could also have a bad u-joint. You would hear the joint squeak long before it would cause a bad vibration. When the rear driveshaft is off check both u-joints.

U-joints were replaced when i had the driveshaft re-balanced. No noises.

The axles just look weird. Vibration is definitely from the rear. I wish I had another rear axles laying around.

 

[liquidswords88]

Re: Warped flexplate? Videos, updated.

If your feeling the vibration with the rear off the ground, I highly doubt it is the axles. With the rim removed there is not enough mass on the hub to transfer the movement into the chassis. I guess if the rear axle bearings were really bad the axle could bounce around in the tube, but you would hear that. It is very hard to bend an axle, I have been racing cars for along time and can count on one hand the number of bent axles I have seen. If you did bend an axle the impact that would of caused it would not be forgotten. I am still leaning towards a bad driveshaft. You said it was rebalanced, but that does not mean it was done right. A out of balance driveshaft will act just like a out of balance tire, it will shake worse at certain speeds. And then at other speeds it will not shake at all. That is what your getting. Try a different driveshaft.

 

[Priceless]

Re: Warped flexplate? Videos, updated.

I've had this vibration since i bought the truck in 2014. I've been trying to track it down what seems like forever. I know I didn't hit anything hard to bend the axles but its possible someone else did. Or Maybe its the bearings.