Question for guys with FTBR diff mounts

[Black10thSVT]

I have the FTBR front and rear diff mounts. I have the thinker one on the bottom and 5 spacers per side.

What is the optimum number of spacers?(how many did you use?)
What is the optimum pinion angle?

I cant find the degree anywhere. I might be over looking it. Im about to check my pinion angle. When I tried it out I noticed a bad vibration coming from the rear of the trans, which leads me believe its to steep. At the time I didnt have an angle finder. Now I do.

Ill let ya know where Im at on a bit.

 

[Black10thSVT]

I can anything apart and put it back, but this is where I have a problem.

Here are my degrees. Can someone help

Front angled up. 86-87*s
Rear angled down. 92-93*s They are close but its hard on your back.

Do I need to pull out a spacer. (Aluminum Washer) To lower the front of the diff.

Something is deff wrong. I have the car on jack stands, and have put it in first gear while idling. Every few seconds I feel a thump. It feel likie its coming from under my feet, and I feel it in the shift knob.

If I cant figure it out Im putting the steeda Poly mounts in the front. And calling it good.

 

[DocB]

Trying to understand.

Front of diff. angled up 3-4*? If so, great job.

Question: Did you mark the driveshaft to pinion orientation before you took it apart? And put it back the same way?

 

[greengt88]

Yep d/s has to go on the same way it came off double check that

 

[sprstr1000]

Measure the pinion angle from the tranny to the DS (for example its +3 )and use your washers to make the pinion angle from the DS to diff the same amount (make it -3)but opposite
I cant remember if the the front is + or -
but you get the idea
I dont remember how many washers I put where,my pinion angle ended up being +4 -4

 

[Black10thSVT]

Well this morning I decided to put my car on the ground and drive it before taking it apart. When I drove it I didnt feel the thump I was feeling every few seconds when the car was on jack stands.

I wounder if the suspension being in full droop could have been causing that. Maybe the halfshafts. Its hard to tell. The shift knob has a slight vib in it, but I cant remember it any worse than before.

I do have a clunk in the driveline but my gears have slack in them thats what that has to be.

Might have to take it to a pro on the one. Im tired of messing with it.

 

[ruthless]

I just dont understand why this stuff is so hard. maybe I am just in a bad mood today or something. :fm:

Everything you could want to know about setting the pinion angle and guess what. They are the same people that made your mounts/bushings.

 

[Black10thSVT]

I just dont understand why this stuff is so hard. maybe I am just in a bad mood today or something. :fm:

Everything you could want to know about setting the pinion angle and guess what. They are the same people that made your mounts/bushings.

FTBR Setting Pinion Angle

Go be in a Bad mood somewhere other than here.

 

[EvilBlack]

Go be in a Bad mood somewhere other than here.

oke:Really, step away from the keyboard.

In my experience suspension hanging can affect the pinion angle enough to cause noises. My experience is with old muscle, but it still should be similar.

 

[Jimmysidecarr]

oke:Really, step away from the keyboard.

In my experience suspension hanging can affect the pinion angle enough to cause noises. My experience is with old muscle, but it still should be similar.

That would be live axles, pinion angle changes with droop and compression on them.

On an IRS it is static.

Full droop can sometimes cause the inside sidewall to touch the bolt head on the IRS subframe rear mount though.

 

[Black10thSVT]

Jimmysidecarr

I'm 95% sure that testing it in full droop cause what I was feeling and hearing. I think the only thing that I'm going to do now is have drive shaft high speed balanced. Just to be sure that's on the up & up.

From what I measured the pinion angle is just about the best its gonna be.

 

[Jimmysidecarr]

Jimmysidecarr

I'm 95% sure that testing it in full droop cause what I was feeling and hearing. I think the only thing that I'm going to do now is have drive shaft high speed balanced. Just to be sure that's on the up & up.

From what I measured the pinion angle is just about the best its gonna be.

Axle CVs may be aged and a little loose, they will behave differently at full droop.:shrug:

 

[ruthless]

Go be in a Bad mood somewhere other than here.

Ok I will! Good luck with your car.