Driveline angle

Measured angle of transmission down 3.5 degree pinion is 1.5 degree down drive shaft is 3.5 down. Is this close? Thanks Bradley

Not sure I understand correctly. It seems your transmission and driveshaft are perfectly in line, but is the pinion 1.5 down from that angle or 1.5 from straight, meaning a 2 degree difference between the shaft and pinion. I think the pinion being 1-2 down from shaft angle is acceptable. It will nose up slightly under load. If it is 2 up from driveshaft, you have to lower the pinion angle.

Driveshaft down 3.5 front to rear? Pinion nose down 1.5 at the yoke? If so, that's 5 degrees negative. Pinion down 1.5 front to rear? That's 2 degrees negative.

What rear suspension... but think of it this
way.. if the trans is pointed down 3.5 and if
the diff was pointed up 3.5 that would be zero
then roll the nose down for what you need

I too see 5* negative neglecting drive shaft angles...........

Have a smart phone?

http://www.tremec.com/anexos/File/TREMEC_Driveline.App.Instructions.pdf

It is ladder bars with dana 60 trany is 3.5 degrees down. Rearend is down 1.5 degrees

Your at 5*.. with a ladder bar you want 1* - 2*

I adjusted to +.5 degrees at pinion. Is that ok? ThanksBradley

Early abody so limited at shimming trany

.5 from what.. what the trans is
EDIT
Set it at 2* pointed up.. that will give you
1.5*

From rearend in ladderbars pinion is now +.5 up

I edited my post above.. look there

Rear was 1.5 down

Thanks been fighting a rumble in car. I have a weight on end of tail housing. 904 trans

That factory weight... if this is a race car you dont
need that weight... it was for a factory issue that
caused the steering wheel to vibrate some...
all they did with that weight was change the
frequency to another point

Should it be smooth if i run it on jack stands. I have them under rear axle and front suspension.

Should if the tires are balanced... did you get the
pinion up to 2*

Yes and took weight off tail housing. Seems better

Are the U-joints in good shape and is the drive
shaft straight and balanced

The yes u joints are new and driveshaft is new. It had vibration after you crossed finish line and left off in 1/8 mile for about 2 seconds. Adjusted ladder bars and now have vibration 20ft before finish line in 1/8 mile.

Thats from having too much pinion angle.. as you let off
the rear tries to roll down but being a ladder bar its
sorta stuck there... the correction in the pinion angle
will take care of that... if you still feel it some you
might have hurt the U-joints or the drive shaft.. you
can go even less on the pinion by .5*(roll it up to 1.5*)
EDIT
Also.. how far is the drive shaft from bottoming
out in the trans... should have 3/4" when sitting

Yes i have 3/4 to 1 inch from bottoming driveshaft

Is the rumble from your lack of rubber bushings? Heim joints will transmit alot of noise.

I understand you trans to driveshaft is limited by the transmission. Can you lower the engine?

There is the ultimate rear universal joint angle and thankfully with ladder bars, it's a small number but like every adjustment it's a comprimise.

We aim for -1 to 0 deg pinion down for ladders for drag racing but when smooth is the goal it's two small angles like a max of 2 deg and matching. When a universal joints runs at an angle the driveshaft slows and speeds up everytime the cross moves. If the angles at each end match the slowing down and speeding up is cancelled at the other end.