Infraction Intense vibration climax

[dure16]

(I’ll never grow up )

My infraction is smooth as butter up until about 60mph and then starts vibrating. Going faster increases the magnitude of the vibrations to the point I can’t continue. It gets loud. (The puns are too easy)

I swear the problem became worse after a mild crash a while back, but I’ve checked everything. Complete tear down. Diffs are solid and shimmed. Bearings are good. Driveshafts are straight. Tires are balanced. I can’t find any cracked suspension parts. Center driveshaft cups replaced with Tekno cups.

Yet the vibrations continue to be a problem.

Any ideas?

 

[Garcbomber]

Still running the factory poly wing? Remove it and try again, also could be an AVC problem.

 

[Sandracer_NL]

Maybe it’s your shaft? (I’ll never grow up too).
Joking aside, looks like you already checked al lot, but have you checked the motor, like the bearings, rotor and shaft? I’ve there is some play somewhere it could explain a louder noise and vibration as the rpm’s get higher.

 

[LibertyMKiii]

Put it on blocks and watch it turn. see where the wobbles occur.
Use the throttle trim on the radio so slowly increase the rpms so you don't have to hold onto the radio.

I'd go in this order of looking closely at things:
1. All outdrive and input cups
2. Then suspension movement = tires balances
3. Then dog bones.

 

[Camaroboy383]

For sure..

 

[Moonstonemike]

Put it on blocks and watch it turn. see where the wobbles occur.
Use the throttle trim on the radio so slowly increase the rpms so you don't have to hold onto the radio.

I'd go in this order of looking closely at things:
1. All outdrive and input cups
2. Then suspension movement = tires balances
3. Then dog bones.

Agreed. Run it with the wheels on and in the air. This way you can narrow down if it's drivetrain related or from the suspension.

 

[Tex Koder]

How high is your AVC set?
Perhaps turn it down a bit..

 

[RedOctobyr]

I like the idea of putting it on blocks and testing it that way. You could presumably also remove the front wheels, to check just the rears, and then switch. At least maybe giving a sense of whether it's a front or rear problem.

 

[dure16]

Still running the factory poly wing? Remove it and try again, also could be an AVC problem.

Yes I’m still running the factory wing and I also use AVC. Great ideas to try. Thanks.

Maybe it’s your shaft? (I’ll never grow up too).
Joking aside, looks like you already checked al lot, but have you checked the motor, like the bearings, rotor and shaft? I’ve there is some play somewhere it could explain a louder noise and vibration as the rpm’s get higher.

Hadn’t thought of that since it’s a pretty new motor. Definitely worth exploring. Thanks.

Put it on blocks and watch it turn. see where the wobbles occur.
Use the throttle trim on the radio so slowly increase the rpms so you don't have to hold onto the radio.

I'd go in this order of looking closely at things:
1. All outdrive and input cups
2. Then suspension movement = tires balances
3. Then dog bones.

I’ll do exactly this. Appreciate it.

How high is your AVC set?
Perhaps turn it down a bit..

Steering AVC at 10%.
Throttle AVC at 0%.

I’m going to try turning it off completely to see if that helps. Thanks.

 

[Senton_Prime]

Not sure what vibrates means.. but if its buttery smooth up until around 60 then I'd eliminate anything mechanical!? When u say vibrate do you mean it jumps/darts left to right like it wont track straight without adjusting the steering!?

 

[dure16]

Not sure what vibrates means.. but if its buttery smooth up until around 60 then I'd eliminate anything mechanical!? When u say vibrate do you mean it jumps/darts left to right like it wont track straight without adjusting the steering!?

It tracks fine but it gets very loud

 

[Senton_Prime]

Have you watched what the shafts do under load, maybe 3/4 throttle!?

 

[Ferrebee88]

What a letdown... I thought this was going to be steamy

 

[Badmofreaker]

(I’ll never grow up )

My infraction is smooth as butter up until about 60mph and then starts vibrating. Going faster increases the magnitude of the vibrations to the point I can’t continue. It gets loud. (The puns are too easy)

I swear the problem became worse after a mild crash a while back, but I’ve checked everything. Complete tear down. Diffs are solid and shimmed. Bearings are good. Driveshafts are straight. Tires are balanced. I can’t find any cracked suspension parts. Center driveshaft cups replaced with Tekno cups.

Yet the vibrations continue to be a problem.

Any ideas?

I have actually bent the pinion shafts were the cups go on front or rear diffs after a bad crash and I could hear a bad vibration when I hit higher speeds

 

[dure16]

I have actually bent the pinion shafts were the cups go on front or rear diffs after a bad crash and I could hear a bad vibration when I hit higher speeds

I'll check for that - thank you

 

[dure16]

A quick update:

I removed the wing.
I turned off AVC.
I installed a different motor and pinion.
I removed the wheels.
I checked the diff pinion shafts.
I put the car on blocks and inspected closely: outdrive/input cups, suspension movement, and dog bones.

The vibration is still there and it seems to be coming from the rear of the car. Grabbing onto the front shock tower feels mostly normal, but if I grab the rear shock tower I can feel it vibrating.

I can't see anything wrong, anywhere. Cups and dog bones look good.

Any other ideas?

 

[Tex Koder]

A quick update:

I removed the wing.
I turned off AVC.
I installed a different motor and pinion.
I removed the wheels.
I checked the diff pinion shafts.
I put the car on blocks and inspected closely: outdrive/input cups, suspension movement, and dog bones.

The vibration is still there and it seems to be coming from the rear of the car. Grabbing onto the front shock tower feels mostly normal, but if I grab the rear shock tower I can feel it vibrating.

I can't see anything wrong, anywhere. Cups and dog bones look good.

Any other ideas?

Another thing to check are the ball bearings in the rear bulkhead and definitely in the wheel hubs.. they may be slightly warped/damaged..

 

[Badmofreaker]

(I’ll never grow up )

My infraction is smooth as butter up until about 60mph and then starts vibrating. Going faster increases the magnitude of the vibrations to the point I can’t continue. It gets loud. (The puns are too easy)

I swear the problem became worse after a mild crash a while back, but I’ve checked everything. Complete tear down. Diffs are solid and shimmed. Bearings are good. Driveshafts are straight. Tires are balanced. I can’t find any cracked suspension parts. Center driveshaft cups replaced with Tekno cups.

Yet the vibrations continue to be a problem.

Any ideas?

Do you have the bearing support for the rear shaft or no?

 

[dure16]

Another thing to check are the ball bearings in the rear bulkhead and definitely in the wheel hubs.. they may be slightly warped/damaged..

All the bearings are good.

Do you have the bearing support for the rear shaft or no?

Yes. New bearings.