Went to track now have a vibration

[Jeffs FRC]

So I went out last night to the track and on the third run when I hit 2nd car bit down and something didn't feel quite right...

The car now has a slight vibration at pretty much all speeds and there is a whining noise coming from the rear. Vibration is the worst around 45-55mph and the whine is loudest at around 70mph.

I jacked the car up this morning and ran it up to 20mph in first just to see if I could find a bent driveshaft or something. The shaft looked to be running true, but both rear wheels have a slight wobble. From just looking it appears to be about 1/8" back and forth on both sides.

Did I bend some axles and fuck the rear up?

 

[Jeffs FRC]

Just got back under the car to take another look at the driveshaft and it too has a wobble...

 

[Greg Hazlett]

Stock d/s?

 

[Jeffs FRC]

Shaftmasters 3.5" direct bolt in.

Car was smooth as silk before the track...

 

[Jeffs FRC]

Update!

Put the stock shaft back in and the car is fine.

I'll be giving Shafmasters a call on Monday to see what they'll do about this...

 

[jgilbert04]

I have heard of others having problems with the Shaftmasters driveshafts also. I hear customer service is pretty good. Good Luck!

 

[dimitrik8890]

wobble

possibly a tire problem. could be chopped or need to be balanced. did u burn them hard before ur runs?

 

[GrnBullitt08]

He just said it was the driveshaft....



Sorry to hear about the driveshaft issues Jeff. Goodluck getting those worked out. How did the car do?

 

[Jeffs FRC]

I have heard of others having problems with the Shaftmasters driveshafts also. I hear customer service is pretty good. Good Luck!

I have heard nothing but good things about the 3.5". Like I said the car ran awesome before that 1-2 shift.

Sorry to hear about the driveshaft issues Jeff. Goodluck getting those worked out. How did the car do?

Track was very inconsistent and only got 3 runs in. Had to pedal it through 1st and 2nd... There is alot left in it for sure

60'-1.92
1/4-12.00
mph-120.7

 

[GrnBullitt08]

I have heard nothing but good things about the 3.5". Like I said the car ran awesome before that 1-2 shift.


Track was very inconsistent and only got 3 runs in. Had to pedal it through 1st and 2nd... There is alot left in it for sure

60'-1.92
1/4-12.00
mph-120.7

Oh yeah....there is alot left in it...a few guys around here run low 11s with that setup. Not bad for the first time out, especially with Matt out there running low-mid 13s lol.

 

[Jeffs FRC]

Oh yeah....there is alot left in it...a few guys around here run low 11s with that setup. Not bad for the first time out, especially with Matt out there running low-mid 13s lol.

Matt was sissy footin it! He offered to let me take it for a pass, but I declined as I didn't feel comfortable beating on his car.

Maybe next time we'll swap cars...

 

[GrnBullitt08]

Matt was sissy footin it! He offered to let me take it for a pass, but I declined as I didn't feel comfortable beating on his car.

Maybe next time we'll swap cars...

Not a bad idea.....He better get those times down soon. Or he is gonna be looking at my tailights too lol

 

[Jeffs FRC]

On a side note I shipped the shaft back to Shaftmasters today. Ill update when they get back to me.

Hopefully it can be fixed! $600 paper weights suck...LOL

 

[EagleStroker]

The thing is, the stock d/s may only be masking the true issue. The stock piece is designed to minimize vibration which is why most of us replace it. Something to think about!

 

[GrnBullitt08]

They don't warranty the driveshaft at all? You just bought that thing.

 

[Jeffs FRC]

The thing is, the stock d/s may only be masking the true issue. The stock piece is designed to minimize vibration which is why most of us replace it. Something to think about!

I thought about that too, but when I was directly under the car with it running around 20mph there was no question that the DS is slightly bent.

Also, the whining has disappeared...

 

[GrnBullitt08]

Well hopefully that's the only issue

 

[Jeffs FRC]

They don't warranty the driveshaft at all? You just bought that thing.

If its something that isn't a workmanship issue I doubt it.

There was a couple rub marks on the shaft, but nothing bad like some Ive seen pics of... Only one of the rub marks I could actually feel by running my fingernail across.

 

[EagleStroker]

I thought about that too, but when I was directly under the car with it running around 20mph there was no question that the DS is slightly bent.

Also, the whining has disappeared...

If the suspension isn't loaded/moving down the road I think it would be hard to rule out everything. Whining will disappear just from the dampening from my experience. I had a similar issue about a year ago and it was caused from my OE UCA bushing basically coming apart.

Good luck working it all out!

 

[Jeffs FRC]

If the suspension isn't loaded/moving down the road I think it would be hard to rule out everything. Whining will disappear just from the dampening from my experience. I had a similar issue about a year ago and it was caused from my OE UCA bushing basically coming apart.

Good luck working it all out!

Thanks for the tip! I will definately check out the UCA. I checked the LCA's and panhard already and they are fine. Not sure why I didn't look at the UCA.