240 spicer heavy duty center support bearing

[sloopy]

That makes sense. I think basically everything that could be wrong with my setup was wrong and resulted in horrible vibrations.

- T5 tailshaft bushing is worn out (leaking oil from the seal and introducing vibrations)

- modified driveshaft was out of balance

- transmission is probably still not in proper alignment

- pinion is pointed downwards

And on top of that I had the spicer center support which is super hard and was transmitting all of that into the cabin very nicely. I'm trying to power through here. It's been a bit discouraging also because The transmission keeps popping out of 5th gear after you get on and off the throttle a few times. You can see it move backwards each time I lift off the throttle. I'm going to try driving it without the boots (boot around the shifter assembly and the interior shift lever boot) and see if that's still happening.

 

[aristg]

All the down angles (^) should add up to the up angles (v), if that makes sense.

So if the trans to 1st section is a 1deg drop, then the 1st section to 2nd section is a 3deg drop.. the 2nd section to the diff needs to be 4deg up. With rubber bushings you'll have many degrees of pinion angle change from drive to coast. If you have no vibes on accel and then a lot on decel in gear, you'll probably want to point the pinion up.

Is there an illustration for this to be more clear ? I am loosing it at the point that the 1st to 2nd section 1 degree drop becomes 3. Can you explain it a bit more ?

 

[cosbySweater]

I have 2 240s one with the 740 mount style (which I was told is better) and the HD style sts sells. The sts bearing is so much nicer then the 740 style. The 740 style flops around quite a bit. The 240 style with the sts bearing is nicer imo, less vibration and more contact area

 

[sloopy]

less vibration with the spicer center support? i figured it would be more because that thing is stiff as all be. and to think i just destroyed that thing pulling it off my driveshaft lol

 

[cosbySweater]

Yea suprisingly the big spicer donut has a lot les vibration then the 940 style at least in my experience

 

[sloopy]

big if true. can anyone corroborate these claims?

 

[cosbySweater]

if you're using it to solve a vibration issue with the t5, the only fix is getting rid of the t5

 

[sloopy]

I'm solving the vibration issues by addressing the root causes like driveshaft balance, driveline angles, and worn out parts like the tailshaft bushing. But I also want to use the best center support for my application. I just presumed the spicer support would transmit a lot more vibrations than the 740 one, and I want to minimize vibrations to a reasonable extent. But I also want a support which is robust and will handle abuse (which I know the spicer is best for).

 

[sloopy]

I love the t5 too much to consider getting rid of it (unless (for some reason) I happen to suddenly have a lot of money and replace it with a tkx)

 

[culberro]

Is there an illustration for this to be more clear ? I am loosing it at the point that the 1st to 2nd section 1 degree drop becomes 3. Can you explain it a bit more ?

I wasn't saying that the 2nd section is a 3deg drop because the 1st section was 1deg. I was using those numbers as an example of what you might come across.

In the image below don't pay attention to the angles/numbers, just the direction that the shafts are going.

The transmission tail shaft is pointing down, the 1st driveshaft section is pointing down further. This creates a down angle and we will represent it as a negative value.
The 1st section to 2nd section creates an up angle, and this will be a positive angle.
The 2nd section to the diff is another down angle, so negative.

Now let's add some numbers:
The trans to 1st section would be a Down angle, let's say it's -1deg between the axis of the trans and DS.
1st section of DS to 2nd section of DS is 3deg up.
2nd section to DS is -3deg down.

Now let's add the angles together:
-1+3+(-3) = -1, so we are not perfectly aligned.
To correct this issue the diff pinion could be rotated so the angle from the 2nd section to the diff pinion axis is reduced. To make things slightly confusing, this would require the pinion to be "dropped" in this example.

If the transmission and the 1st section of the DS are perfectly in line, then you can treat the 2nd section and pinion like a 1pc shaft with respect to angles.