Topic: Driveline lash/ axle wrap?

[1980firstgen20r]

Ok guys If you've seen my other posts of chasing the noise/ vibration I hear and feel while in 2WD, if you haven't seen my other posts take a gander through this fourum category and check them out
I've made a short video of what I'm hearing
https://m.youtube.com/watch?v=t0MSQF3Npcg

[OVRAROK]

Do you have c.v. at t case?
Also what is the driveline angle compared to the rear pinion angle.

[1980firstgen20r [OP]]

Do you have c.v. at t case?
Also what is the driveline angle compared to the rear pinion angle.

No cv, standard two u joint shaft
12* angle on the shaft itself
76* at the pinion
90* at the Tcase
So that's 14* out of parallel? Right?
And yeah I know that's really bad

[OVRAROK]

No cv, standard two u joint shaft
12* angle on the shaft itself
76* at the pinion
90* at the Tcase
So that's 14* out of parallel? Right?
And yeah I know that's really bad

If your driveline angle is 12° degrees, your pinion in rear should be at 10°, that 2° pointed toward the ground, allowing for axle wrap

[THK Matt]

im struggling to comprehend how 90* can be the number at the TCase. 90* is a right angle.

[1980firstgen20r [OP]]

im struggling to comprehend how 90* can be the number at the TCase. 90* is a right angle.

That's exactly the angle could be different on flat ground. But what you need is the diffence between the two angles
I'll post pics of it when I get home after work today if that helps you "comprehend"

[1980firstgen20r [OP]]

im struggling to comprehend how 90* can be the number at the TCase. 90* is a right angle.

Also the tranny/ transfer case is a w56 single case. I swapped out the L43 and installed a bud built crossmember to accommodate the w56. I hope that helps you comprehend.
1980 20r long bed.

[OVRAROK]

http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml

[THK Matt]

90* is like an L. Pictures would help.

[1980firstgen20r [OP]]

90* is like an L. Pictures would help.

Ohhh you just wait. I know what a right angle is.. i was baffled my self when I checked the angle, give me a few hours to get home and I'll show you

[1980firstgen20r [OP]]

http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml

Thanks for the link but I've already been referred to it

[OVRAROK]

 

[Gnarly4X]

Trying to analyze vibrations over the internet is like sniffing flowers through your butt. 

BUTT.... there are some diagnostic things we can do to help discover where the vibes are coming from. 

There's quite a bit of "stuff" on this.. 

Here's a good one....   http://www.hotrodhotline.com/md/html/drive_shaft_harmonics.php

Gnarls. 

[1980firstgen20r [OP]]

90* is like an L. Pictures would help.

Ok guy'a finally had time to get these pics up
http://m.imgur.com/a/XPidP
I did move to a more level'd surface and got different measurements but close to the ones before
Rear drive shaft angle reading @ 16*
Rear pinion angle reading @ 76*
T case angle reading @ 86*
Give me some feed back.
Also I've been trying to diagnose this for a while, I plan on installing chevy 63's in the rear and I know because of the longer shackles my pinion angle will slightly change but since I took the video of what's going on in the rear end it's got me thinking y'all might have some more input about what I can do

[Gnarly4X]

1980firstgen20r,

What do you think is causing your vibrations?

When do you feel the vibrations?

If the vibrations are caused by out of phase U-joints or driveline angles, it’s usually a fairly straight forward fix.

If the vibrations are caused by bad U-joints, or pinion bearings, they usually can be detected by checking for excessive movement.

Some axle wrap is normal.  Excessive axle wrap may occur  on heavy acceleration, braking, and on the trail while applying lots of throttle torque, like rock crawling.

https://www.drivelinesnw.com/part-trouble-shooting/vibration-analysis/angle-analysis/measuring-and-correcting-angle-problems/

https://www.4wd.com/p/pro-comp-degree-shim-99-200/_/R-DFCW-99-200?utm_source=google&utm_medium=cpc&utm_campaign=shopping&emlprox=out&ppcfon=1&gp=1&scid=scplpEXP99-200&sc_intid=EXP99-200&gclid=EAIaIQobChMInefJv_rO1QIVgYl-Ch18MgRZEAQYBCABEgLnsPD_BwE


Gnarls. 

[THK Matt]

Ok guy'a finally had time to get these pics up
http://m.imgur.com/a/XPidP
I did move to a more level'd surface and got different measurements but close to the ones before
Rear drive shaft angle reading @ 16*
Rear pinion angle reading @ 76*
T case angle reading @ 86*
Give me some feed back.
Also I've been trying to diagnose this for a while, I plan on installing chevy 63's in the rear and I know because of the longer shackles my pinion angle will slightly change but since I took the video of what's going on in the rear end it's got me thinking y'all might have some more input about what I can do

tcase 4*, rear pinion 14*,

[1980firstgen20r [OP]]

tcase 4*, rear pinion 14*,

Am I reading the angle finder wrong or something?

[THK Matt]

Am I reading the angle finder wrong or something?

yes

[1980firstgen20r [OP]]

yes

The how should I read it, I don't understand. Would appreciate it if you could explain it and not be so short...

[1980firstgen20r [OP]]

1980firstgen20r,

What do you think is causing your vibrations?

When do you feel the vibrations?

If the vibrations are caused by out of phase U-joints or driveline angles, it’s usually a fairly straight forward fix.

If the vibrations are caused by bad U-joints, or pinion bearings, they usually can be detected by checking for excessive movement.

Some axle wrap is normal.  Excessive axle wrap may occur  on heavy acceleration, braking, and on the trail while applying lots of throttle torque, like rock crawling.

https://www.drivelinesnw.com/part-trouble-shooting/vibration-analysis/angle-analysis/measuring-and-correcting-angle-problems/

https://www.4wd.com/p/pro-comp-degree-shim-99-200/_/R-DFCW-99-200?utm_source=google&utm_medium=cpc&utm_campaign=shopping&emlprox=out&ppcfon=1&gp=1&scid=scplpEXP99-200&sc_intid=EXP99-200&gclid=EAIaIQobChMInefJv_rO1QIVgYl-Ch18MgRZEAQYBCABEgLnsPD_BwE


Gnarls. 

I believe what's causing the vibration/ gear grinding noise is the drive shaft being out of parallel. The u joints are brand new. Had the guy at the drive shaft shop replace them when I had him shorten down the shaft to accommodate the w56. And the vibration/ noise happens when I'm in 2WD driving on the pavement. In 4WD the noise isn't bad at all.
I also Checked the play on the ring and pinion when the original axle was in the truck and it seemed fucked up to much play. So I installed a 2nd generation axle that I had already taken apart and rebuilt. So I trust the axle/ ring and pinion. What I don't trust is the rear drive shaft angle being out of parallel. I don't know if I need to point my pinion up or down to make it match the T case angle. I have a few other threads in this category with some more info if your interested in reading them. Getting tired of posting the same thing over and over