Horrible Shudder

[jpalmer]

I have a recent issue with a horrible shudder under load or when releasing the clutch. It has been present for the last few hundered miles and I wrote it off to hotspots on the flywheel because it only did it when letting out the clutch. It has been getting much worse lately and it even present with the clutch out and under power. Motor runs fine with no vibrations in neutral, and is worse at lower RPMs under a load. The t-case mounts are fine and engine mounts appear good. Any ideas to check out?

 

[Apogee]

My first guess would be a warped/tweaked clutch friction disc? This normally would only be felt when releasing the clutch under load, but if it's slipping as well, then you might feel it at lower RPM's under load.

 

[jpalmer]

It shakes throughout the entire power band when applying throttle but is definitely worse at lower RPMs and while releasing the clutch.

 

[needabronco]

Time for a clutch, and if you already suspect hot spots on your flywheel I'd say to get it resurfaced while it's apart...

 

[jpalmer]

Time for a clutch, and if you already suspect hot spots on your flywheel I'd say to get it resurfaced while it's apart...

Close, sounds like it's time for a tranny swap... ;D

 

[ugly_od_eb]

I have a new LUK clutch in mine and it used to do that, Check your U joints, Output on the T case (for twist play) and make sure your U bolts are tight. Try letting on/off the throttle in first, If it jerks hard/late in between decel and accel then it could be the mounts/U joints...

 

[jpalmer]

I will give that a shot this afternoon and post back, thanks.

 

[Rockrawl]

What about clutch adjustment? While I am letting mine out it will shimmy a little and I imagine that if it didn't engage fully that it might shake a lot and throughout the rpm range. Just a thought

 

[jpalmer]

What about clutch adjustment? While I am letting mine out it will shimmy a little and I imagine that if it didn't engage fully that it might shake a lot and throughout the rpm range. Just a thought

How do you check that? Just adjust the cable and see if it makes a difference?

 

[jpalmer]

I have a new LUK clutch in mine and it used to do that, Check your U joints, Output on the T case (for twist play) and make sure your U bolts are tight. Try letting on/off the throttle in first, If it jerks hard/late in between decel and accel then it could be the mounts/U joints...

I have about 1/8" of play at the T-case while in gear with the driveshaft disconnected at the rear axle. I have also about 3/4" of play at the rear axle with the driveshaft disconnected at the T-case, tires on the ground of course... U-joints are tight and only have about 250 miles on them. The first 200 u-joint miles are on a 4" lift and the last 25 miles are on a 6" lift.

 

[ugly_od_eb]

Try checkin the bellhousing/trans bolts (4 of them) i have a prob with mine getting loose but thats because of a broken motor mount... Idk what it could be man, how many miles are on the clutch?

 

[jpalmer]

The clutch can't have much more than a few thousand miles but it is 10 years old. :-X When I bought this thing two years ago it was bone stock with a "new" tranny, clutch, and motor but it has been sitting in a farm yard for virtually 8 years since the new equipment.

 

[DirtDonk]

Re-check your centering ball in the double-cardan joint at the t-case. Unless it's new too?
You said your last few miles were on a 6 inch lift and you're having the problem more recently too. I'd say that although it sure sounds like a clutch, you should look to driveline angles.
Maybe it was not as bad at first, but as the joints were getting torn up, it got worse. Could happen that way.

I know you checked the joints for play, but it could still be a driveline issue and certainly a centering yoke issue with the double-cardan joints.

Paul

 

[DirtDonk]

Or maybe run it in 4-hi with the rear shaft completely removed to see if it still does it. That might isolate it some more.

Paul

 

[bronko69er]

How is your pinion angle after the shackle flip?
I had to shim mine.

 

[jpalmer]

I would love to run it in 4-hi but I have not gotten my front driveline extended yet since the larger lift so I cannot...

Jesse, I am at work so I cannot check to be positive but I looked before and my pinion angle looked fine. I am using all spring and no block so I think that should help my angle.

What do I check for on my double-cardan joint? I have never messed with those before.

 

[bronko69er]

I only mensioned that becuse I had excessive U-joint vibration after the shackle flip because the pinion was too high.

 

[jpalmer]

I only mensioned that becuse I had excessive U-joint vibration after the shackle flip because the pinion was too high.

Mine only seems to vibrate when under load or releasing the clutch, not when cruising so that should rule out the driveline being the major culprit right?

 

[bronko69er]

Mine only seems to vibrate when under load or releasing the clutch, not when cruising so that should rule out the driveline being the major culprit right?

If the pinion is already high, load will raise it more, increasing the vibrations, but vibes when releasing the clutch does point elsewhere.

 

[jpalmer]

I'll check that out when I get home to eliminate that, thanks Jesse.