Extreme clutch shudder

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Here's an update, I spoke with Brewers Performance, they told me it sounds like pinion angle issue, they suggested that I wedge a block between the pinion snubber and the floor board and see if it stops, It did stop, without the wood block the differential lifts up and down causing the shudder, I'm waiting to hear back to see what they say.
 
I would think the pinion would have to be 'yards' off to cause that. Is this a stock Mopar rear? Unless you have the springs all jacked around, should not be an issue. Have you measured the pinion angle?

Put the car on some sort of blocks so it's fairly level with weight on the suspension. Measure crankshaft centerline for angle. Measure pinion angle. The difference between the two If one is up the other down (from level) you'll have to make allowance for that

The "normal accepted" seems to be having the pinion about 2* down relative to the crank/ transmission

Regardless of pinion angle, you may have a suspension problem, bushings, loose shackles or U bolts or broken leafs. Don't discount that and check carefully.
 
I would think the pinion would have to be 'yards' off to cause that. Is this a stock Mopar rear? Unless you have the springs all jacked around, should not be an issue. Have you measured the pinion angle?

Put the car on some sort of blocks so it's fairly level with weight on the suspension. Measure crankshaft centerline for angle. Measure pinion angle. The difference between the two If one is up the other down (from level) you'll have to make allowance for that

The "normal accepted" seems to be having the pinion about 2* down relative to the crank/ transmission

Regardless of pinion angle, you may have a suspension problem, bushings, loose shackles or U bolts or broken leafs. Don't discount that and check carefully.
Stock rear end, I have not checked pinion angle yet, but from what I can see the diff looks level with the driveshaft
 
I would double check your u-bolt torque, and spring hanger bolts. I left mine loose on accident once and had chatter issues like yours.
Now I have wheel hop issues, but only when leaving at full throttle from idle RPM.. LOL.
 
Something has gotta be broken or loose somewhere. This isn't making sense.
 
Something has gotta be broken or loose somewhere. This isn't making sense.
completely rebuilt suspension everything is tight, they are original leaf springs I disassembled and rebuilt, all u-bolts are new and tight, new leaf spring shackles and shackle boxes, motor mounts are good, transmission bushing good, care only shudders in 1st gear not in second or reverse, the tech at brewers I've been talking to seems very sure its pinion angle issue.
 
Out of the box, can you rig a camera and video the pinion windup event? Maybe that could help reveal the issue for you.
 
Brewers is right on the money with pinion angle. Myself and another member both switched from autos to manual transmission. Couldn't even pull out slowly without the entire car shaking. So much that the glovebox would open and hood bolts backout. Checked clutch, flywheel, mounts... tried 3 finger and centerforce. Same issue. Talked to an old engine builder and racer near me. He immediately said, "Its pinion angle." I couldn't imagine it since I installed everything using stock mounts and springs. I bought Calvert racing 4 degree shims. Put them in, problem solved instantly. He told me that people do not realize how by even pulling away slowly how violent movement of parts are with 4 speed engagement.
This solved the other members problem too. I fought this issue for more than a year. Even thought about going back to automatic.
 
Update: Installed 4 degree pinion shims, still having the same problem. Removed clutch for the third time checked flywheel run out was within specs, the clutch I had installed was A Borg & Warner clutch from Brewers, I decided to install a perfection clutch which was to OEM specs, well it worked no shudder nice and smooth
 
Interesting.......do you suspect whether it is the disc or the pressure plate? Is there looseness in the old disk spring hub? Post a photo.........
 
Interesting.......do you suspect whether it is the disc or the pressure plate? Is there looseness in the old disk spring hub? Post a photo.........
If I had to guess I would say the disk because I had hot spots on both the flywheel and the pressure plate
 
Did you ever measure the distance from the disc to the fingers to find if they were different ?
That'd give you a hot spot .
 
......the clutch I had installed was A Borg & Warner clutch from Brewers, I decided to install a perfection clutch which was to OEM specs, well it worked no shudder nice and smooth

Can you measure around the B&B disc with a caliper? If it's flat and the hub isn't bent for some reason, all that's left is the plate.
FWIW, MP provides this finger height jig (less specific instruction)............
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Here's an update, I replaced the clutch with a OE style from Precision Clutch, no more shudder. I let brewers know what my findings were and they refunded the cost of the clutch, I can't say enough about Brewers Customer Service both Lisa & Dan are great.
 
Here's an update, I replaced the clutch with a OE style from Precision Clutch, no more shudder. I let brewers know what my findings were and they refunded the cost of the clutch, I can't say enough about Brewers Customer Service both Lisa & Dan are great.
Great people. Thanks for the update.
 
Here's an update, I replaced the clutch with a OE style from Precision Clutch, no more shudder. I let brewers know what my findings were and they refunded the cost of the clutch, I can't say enough about Brewers Customer Service both Lisa & Dan are great.

Do you have a website for Precision Clutch? I did a search and the results were confusing.
 
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