Vibrations at 80+

[OldZeuski]

It's definitely within spec. I need to actually measure my Ford and LMR shafts to see the difference. I had them side by side and it was obvious. I'm currently nursing a total knee replacement and plan on installing the TKX on Aug.1st. I'll measure the shafts then.

I’m curious, has your car had this similar vibration since you purchased it or did it develop over time?

 

[dsrtjeeper]

I’m curious, has your car had this similar vibration since you purchased it or did it develop over time?

It was bone stock when I bought it and it didn't vibrate. I installed 4.10 gears and it vibrated. This is a very common theme. The driveshaft picks up speed with the higher numerically gears. That's when any little issues rear their ugly heads. I even switched gear brands and that didn't help.

 

[OldZeuski]

It was bone stock when I bought it and it didn't vibrate. I installed 4.10 gears and it vibrated. This is a very common theme. The driveshaft picks up speed with the higher numerically gears. That's when any little issues rear their ugly heads. I even switched gear brands and that didn't help.

So you see it at 80 mph tho?

I’ve got 3.73. But 3k rpm in 5th is the same whether you’ve got 2.73 or 4.10 as far as the drive shaft is concerned. That said, 3k in 5th with 2.73 used to be like 120 mph or something.

Hmmmm……

 

[dsrtjeeper]

So you see it at 80 mph tho?

I’ve got 3.73. But 3k rpm in 5th is the same whether you’ve got 2.73 or 4.10 as far as the drive shaft is concerned. That said, 3k in 5th with 2.73 used to be like 120 mph or something.

Hmmmm……

For every revolution of the ring gear, the driveshaft spins 4 times with 4.10 gears. 3.73 gears would have less driveshaft rotations per one revolution of the ring gear. Stock 2.73 gears would have less driveshaft rotations. Right?

Yeah, mine starts vibrating around 80.

 

[OldZeuski]

For every revolution of the ring gear, the driveshaft spins 4 times with 4.10 gears. 3.73 gears would have less driveshaft rotations per one revolution of the ring gear. Stock 2.73 gears would have less driveshaft rotations. Right?

Yeah, mine starts vibrating around 80.

For a given speed yes, more rpm and therefore more driveshaft rotation is required for higher rear ratios.

I’m just thinking out loud.

 

[dsrtjeeper]

For a given speed yes, more rpm and therefore more driveshaft rotation is required for higher rear ratios.

I’m just thinking out loud.

The higher driveshaft speed seems to be key. That's why I suspect the driveshaft is whipping like it did on my '95.