Thoughts on shudder???
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Thoughts on shudder???
My apologies if this has been discussed before. I just got my truck back from having some work done. Thr rear axle yoke was replaced due to a leaking seal, and i had the carrier bearing replaced in an attempt to cure a vibration i occasionally have. However, now when i start to accelerate from a stop, i get a shudder. It goes away quickly. I get this shudder if i start (takeoff) in 1st, 2nd, or 3rd gear from a stop. What are your thoughts?
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From: Isanti, MN
If they replaced the yoke, I assume they also replace the U–joint with it?
It almost sounds like the you joint is binding when you're taking off. When you apply power from a stop, the axle is going to deflect and place the U-joints under a greater angle. That might be enough to cause a dry joint to have issues and feel normal when the axle is a more neutral position. Just a wild guess, I would ask your shop about that joint.
It almost sounds like the you joint is binding when you're taking off. When you apply power from a stop, the axle is going to deflect and place the U-joints under a greater angle. That might be enough to cause a dry joint to have issues and feel normal when the axle is a more neutral position. Just a wild guess, I would ask your shop about that joint.
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From: Home Base Nebraska
If it's a limited slip put some friction modifier in it and give it a few miles. If the clutches are really dry they with jump and unload even if you are going straight because all it takes the tires to be a little different in size especially if you are loaded because the tires have a harder time slipping to make up the difference.
Denny
Denny
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Truck is stock with 3:73 gears. The shudder happens with no weight in the truck. Ujoints were replaced june 2016 and have about 20k miles on. The mechanic said they didn't need to be replaced. I jacked the truck up today and watched the driveshaft as someone pushed the accelerator. It looked like it was balanced. Spinning didn't look like a uniform rotation. I also had the fluids changed in the front and rear diff, and the transfer case while it was there. All i know is this shudder didn't exist when i dropped it off.
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From: Isanti, MN
If it's a limited slip put some friction modifier in it and give it a few miles. If the clutches are really dry they with jump and unload even if you are going straight because all it takes the tires to be a little different in size especially if you are loaded because the tires have a harder time slipping to make up the difference.
Denny
Denny
I f it happens going straight, then it can’t be the LSD because the clutch plates remain stationary with respect to each other.
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From: Isanti, MN
Look elsewhere if it happens in a straight line, the clutches are stationary in that situation. Friction modifier wouldn’t affect this.
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But i probably should add some seeing as i don't see it on my repair bill? Should i siphon some diff fluid out before adding the friction modifier?
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From: Home Base Nebraska
Denny
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From: Home Base Nebraska
Denny
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From: Home Base Nebraska
Denny
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From: Land of Taxes
Check the things that were removed for the repair...everything tight?
Is the carrier mount tight?
Grab the drive shaft at the rear end and push up/down and see if the yoke or the pinion moves. There should be no detectable up/down deflection.
"Spinning didn't look like a uniform rotation". Define this statement?
Is the carrier mount tight?
Grab the drive shaft at the rear end and push up/down and see if the yoke or the pinion moves. There should be no detectable up/down deflection.
"Spinning didn't look like a uniform rotation". Define this statement?
Thread Starter
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Elder User
Joined: May 2007
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Check the things that were removed for the repair...everything tight?
Is the carrier mount tight?
Grab the drive shaft at the rear end and push up/down and see if the yoke or the pinion moves. There should be no detectable up/down deflection.
"Spinning didn't look like a uniform rotation". Define this statement?
Is the carrier mount tight?
Grab the drive shaft at the rear end and push up/down and see if the yoke or the pinion moves. There should be no detectable up/down deflection.
"Spinning didn't look like a uniform rotation". Define this statement?
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From: Home Base Nebraska
Its really hard to tell if there is any runout on that slip joint because there is to many things rotating like balancing weights and clips for the boots. But I'm really starting to think you may have a bad U joint. Get your rear wheels off the ground agian and alien the joint so its straight up and down and see if there is any up and down movement, then try it again after rotating the shaft 90' and do it agian, do it agian until all 4 joints have been pointing down. You have to put some force on the joint when checking it not just a little push. If you get any movement your U joint is bad. The one I just replaced on my F150 only had one of the bearings bad and I had to really get after it to get any movement and when I removed the shaft it felt good but i knew there was movement so I beat it out and only one bearing was dry with all the neddle bearings wore flat. Check all the joints.
Denny
Denny