Driveline angle

[Joker11]

So here is a problem I am having....
I have a 1982 Chevrolet C-30 Crew Cab (1 ton truck 2 wheel drive) with dual rear wheels.
what I did may sound crazy to a lot of people, but it is just what I wanted to do. I lowered the truck 4 inches in the rear of the truck and I slammed the front of the truck till it couldn't go any lower.
The effect on the driveline since the rear end is raised, causing the truck to be lowered, is that the driveline pointed upwards, instead of downwards.
I did a lot of reaserch on driveline angles. Ugh...forever. I had to make a new crossmember at the carrier bearing to raise it up to achieve an acceptable angle. I may not have it just right yet...as there is still some vibration. I shimmed the carrier bearing, I shimmed the transmission output shaft, I shimmed the angle and adjusted the pinion....
Has anyone else had to go through this nightmare yet? What did you do? Fix it, fix it, fix it until you got it right? Or did you take it to a pro and pay for it and that was that?
:confused:

[MicroZone]

I'd have to do some tracking but I think the drive or pinion angle has to be a certain amount...and within only a degree or two. I would also try talking to a few four wheel drive shops or going on the forums. They will give you an idea on pinion angle and such.

Edit: did a quick search on google with " pinion angle on lowered trucks" and came up with quite a few good sites. One site has many accessories for properly lowering your truck. One such item is this:

PINION SHIM:
A pinion shim is used to correct your pinion angle. Pinion angle is the angle where the driveshaft and differential meet. Sometimes when you lower a truck the pinion angle is changed enough to cause the driveshaft to bind. A pinion shim can be used to keep the pinion angle at factory specs and prevent or correct this problem.

Hope this helps!

[metalworks]

is it one drive shaft or a short one to the carrier brg and a longer one the the rear end? If its two shafts did you take them apart? the reason for asking is they are balanced together, as one bolted up unit, that could also be the vibration issue. just a thought. I have the same problem with my truck, had to change the carrier brg. didnt mark the shafts and put it back together wrong. just my 2 cents

[zapster]

in the final end of it all the pinion angle should be around 2 or 3 degrees negative of level with the driveshaft...just sitting there....

with tourque on it... it should stay somewhat even..

...zap!

[MicroZone]

Zap has it, he's built a few cars.

[orphan68]

That's correct ,2 or 3 degrees, with 3 being the target.
Tony