Vibrations felt through acceleration, need some input

[nickstobias]

Hello everyone, so My car is making a weird vibration from accelerating from slow speeds to high, A few months ago I had a RXT put in my Kilpatrick Engine and Transmission in Waukesha Wi. They have a great reputation and do good work. Fastforward a few months later I have my car at Firestone(only place I could get into to change a serpentine belt) and when they drove it they told me it was the clutch? The clutch is not slipping and im getting full boost, I think its the driveshaft or a bad U joint. Any idea on what this could be?

 

[hotcobra03]

When sitting still,if you raise rpms do you still feel vibrating?

Out of balance clutch?

 

[Vinnie_B]

Hello everyone, so My car is making a weird vibration from accelerating from slow speeds to high, A few months ago I had a RXT put in my Kilpatrick Engine and Transmission in Waukesha Wi. They have a great reputation and do good work. Fastforward a few months later I have my car at Firestone(only place I could get into to change a serpentine belt) and when they drove it they told me it was the clutch? The clutch is not slipping and im getting full boost, I think its the driveshaft or a bad U joint. Any idea on what this could be?

***Driveline vibration issues at cruising speeds. Inspect the following:

• Missing weights or damage to driveshaft
• Worn U-joints
• Misalignment of yellow dot on driveshaft-to-yellow dot on pinion flange plus or minus 1 bolt hole
• Worn or damaged driveshaft center bearing support
• Loose axle pinion flange bolts
• Excessive axle pinion flange runout
• Excessive transmission flange runout
• Binding or damaged driveshaft CV joint
• Excessive driveshaft runout and/or driveshaft out-of-balance
• Driveline angles out of specification
• Transmission mount not centered

***Clutch-related vibrations

• Engine component grounding against frame
• Accessory drive belt
• Flywheel bolts
• Flywheel
• Imbalanced clutch pressure plate

 

[nickstobias]

When sitting still,if you raise rpms do you still feel vibrating?

Out of balance clutch?

No only when I accelerate


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[nickstobias]

***Driveline vibration issues at cruising speeds. Inspect the following:

• Missing weights or damage to driveshaft
• Worn U-joints
• Misalignment of yellow dot on driveshaft-to-yellow dot on pinion flange plus or minus 1 bolt hole
• Worn or damaged driveshaft center bearing support
• Loose axle pinion flange bolts
• Excessive axle pinion flange runout
• Excessive transmission flange runout
• Binding or damaged driveshaft CV joint
• Excessive driveshaft runout and/or driveshaft out-of-balance
• Driveline angles out of specification
• Transmission mount not centered

***Clutch-related vibrations

• Engine component grounding against frame
• Accessory drive belt
• Flywheel bolts
• Flywheel
• Imbalanced clutch pressure plate

Thank you


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[nickstobias]

It’s only when I accelerate not when I’m cruising


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[1Kona_Venom]

subbing for constructive comments

 

[nickstobias]

It will be back at the shop in a few weeks, Firestone says it’s the clutch when you take off but I told them it’s a slight shudder, they aren’t getting what I’m trying to explain and I’m not sure if the tech really drove it more to see what I was talking about


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[MG0h3]

I’d look at the driveshaft and angle.

Has this been going on ever since the clutch went in?

Tire issues are typically speed related and not just accelerating and you can drive through it.

Anytime a transmission is failing it makes all kinds of noise, typically that’s the first warning. Not vibration.

Since the driveshaft was just out, I’d take a look and see if you can see an old outline on the pinion flange which would mean they installed the driveshaft in a different orientation.

If you can’t see the outline, you might just try flipping the driveshaft 180*. You can just pull the four bolts at the pinion flange and either rotate the DS or rotate the tires if they are off the ground.


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[nickstobias]

It did a little vibration when driving, honestly I didn’t think anything of it thought it was the clutch getting slowly broken in. The clutch grabs with no problem with zero slippage and still pulls hard but when I floor it it vibrates much more


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[MG0h3]

A slipping clutch can chatter that will seem like a vibration but it’s pretty violent.

I’d suggest checking that DS install.


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[Vinnie_B]

subbing for constructive comments

THREAD STALKER......

 

[robvas]

Go get a $5 angle checker and check the angles on the transmission and driveshaft. They should be opposite, but close.

 

[railroad]

Under acceleration, engine tq might be moving exhaust, engine, etc making contact with body, frame or rigid part of car. While cruising engine will not be angled over, resulting in no vibration.
good luck,

 

[01yellercobra]

If it was good for a few months after the clutch install I'd think the clutch is good. If it just started I would check the u-joints.

And I wouldn't trust Firestone with my lawnmower.

 

[tomshep]

How many miles on it? Motor mount? Tranny mount?

Tom

 

[nickstobias]

I’ll know next week has 32k original and 8k on new shortblock


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[nickstobias]

They said the issue was the front tires were cupped pretty bad with uneven wear and they were loud at cruising speed, eveything else was looked at from the clutch to the drive train drive shaft, etc Guess its time for new tires which sucks as there is plenty of life left on them

 

[Bullitt1448]

Take a good look at your inner/outer tie rod ends when you get new skins, something caused the cupping.

 

[nickstobias]

Ugh still doing it after replacing front tires, its annoying, they inspected everything and said everything was fine, and when they drove it of course it didnt do it. Its gotta be a suspension issue or maybe its normal with the RXT?