What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

fixed, please delete

JEBSR

JEBSR

1/2 ton status
Joined
Dec 23, 2004
Posts
1,541
Reaction score
0
Location
Clarksville, TN
I know this subject is all to common but there is something I'm not sure about that I could use some help with. Just pulled the 12 bolt out of my 87 blazer and I am putting in a 14 bolt ff from an 86 k-30. I cut the perches off and loosly bolted the diff in with all weight on the diff in order to get springs loaded to measure pinion angle. My transfer and pinion are perfect but it and looks to be close to the old marks(where perches were previously mounted) but when I put an angle finder on the driveshaft the angle is right at 30 degrees downward. The only changes I made during the axle swap was pulling the 6" skyjacker blocks and installing 6" skyjacker springs. Axle angle was much less with the 12 bolt with no vibrations. Any ideas? Am I doing something wrong?:confused:

ps. can't afford a cv after purchasing the 1 tons for know so what do I do with this setup?
 
Last edited:
get a pic and we can help ya out better.
If you dont have a CV then you angles should be parallel meaning the output at the T-case should be running parallel with the axle pinion.
Some thing like this _
/
-
 
2joint_angle.gif


This should cover the angle measuring part
 
My angles are correct as in the picture my concern is overall angle of shaft (almost 30 degrees). I'll go take a pic real quick and show you what I mean.
 
driveshaft angle

here are 3 pics. Hard to see but angle of transfer and diff are identicle. Oh yea ignore the stands, the truck isn't touching them.

PANA0055.JPG

PANA0056.JPG

PANA0057.JPG
 
ya thats a pretty big angle. do you have you Tcase shimmed down already?
 
about 1 inch. Just don't understand why the differance between using the blocks and the springs. Was working fine before with not neer the angle.
 
Drive shaft looks way short to me:confused:
 
How much of the yoke is in the T-case?
That does look a little steep on the u-joints. Might have a little vibration.
The spring perches on the 12 bolt were most likely in a little different location than those on the 14B
 
Sorry to hijack but...

Is there an information source that explains drive shaft angles in detail?
Being new to modifying / lifting trucks it seems a bit confusing to me because I am unsure of where the angles are taken from and under what conditions

Any help would be appreciated , thanks in advance

BTW yes I have searched but after reading through lots of posts I still am unsure about it

Bump
 
If that is the stock shaft the splines do not go all the way to the end of the slip yoke, therefore you need a longer shaft for the splines to have enought contact to move the rig foreward. Are you sure you have that much slip yoke in the t-case? From the pick it looks like you would be lucky to have and inch.
 
driveshaft angle

It measured just over 2, but your still right it's really too short, just trying to get it out of shop to move to new location. Probrable just need to wait and get a cv shaft instead of breaking it trying to half@#s fix it.
 
JEBSR said:
I have about 2-2.5" in the transfer housing. I know it's a little short and I plan on getting a cv shaft later. I am afraid that if I weld the spring perches on with these measurements I may have to change them when I get a cv shaft.


here is the sight I got my info on http://www.pirate4x4.com/tech/billavista/PR-shaft/index2.html
Click to expand...

You are going to have to reweld when you get your CV shaft later . With a CV you basically point the pinion straight at the transfercase . Maybe down a degree or two to account for axle windup when your driving .

I got about perfect with stock perches and shackle flip , doesn't vibe at this angle , I never measured but it looks down just a hair so its perfect driving :k5: :k5:

700784_4_full.jpg
 
driveshaft angle

Well thanks for comfirming and giving additional infor on this. Uncle Sam pays my in 3 days so I guess I'll just bite the bullet and order a new cv shaft so I only have to weld once and do it right the first time.;)
 
Questions for you.

In this picture is the truck supported by the jackstands only? Is the axle drooped all the way down? Or is the weight of the truck on the axle?

http://coloradok5.com/forums/attachment.php?attachmentid=2024&stc=1

If the weight of the truck is on the axle and this is ride height you will need a new driveshaft. That driveshaft is almost bound up as it sits. The first time you flex the truck out it will bind the driveshaft and the driveshaft will break.

I did some grinding on my stock driveshaft to get a little more angularity out of it but during my tests I drooped the axle down and the driveshaft ujoint will bind up at not much more then that.

If that picture of the driveshaft is with the axle all the way drooped down then you can probably run that driveshaft for awhile. Just spin the tires with the truck in neutral and see if the ujoint is bound up. If it is then you need to limit the suspension of get a new driveshaft.

I had to end up limiting my maximum droop of the axle so that it would not bind if the rear axle was allowed to flex all the way down. If you bind up a driveshaft ugly things will happen. Don't ask me how I know.

Harley
 
driveshaft angle

The stands are just sitting there from when it was in the air, they actually are about an inch below the frame. Weight is on the axle.
 
JEBSR said:
about 1 inch. Just don't understand why the differance between using the blocks and the springs. Was working fine before with not neer the angle.
Click to expand...

blocks might have had a taper cut to them. the 14b is 1" longer than a 12b IIRC, so it makes the distance between ujoints that much closer, which hurts angle even more. probly a combination of the two.
 
You must log in or register to reply here.

Latest Posts

Top Bottom