How do these driveshaft angles look?

[ragedracer]

I just completed my lift - shackle flip in the rear, ended up with ~5" of lift. I'm getting a little vibration now, at about 25mph, very noticeable under throttle, goes away when I let off the gas.

Do these angles look in range, or am I gonna have to do something else?

 

[blazerboss 85]

youll probly get a little bit of vibes on the transfer case end but i wouldnt be too worried just check it every so often to make sure the joint isnt going out and grease it often the axle end looks good to me about the same as my blazer

 

[resurrected_jimmy]

The angle is perfect for a CV. The joint at the rear axle sholdn't be pointing straight at the t-case in your set up. A shim under the leaf packs will fix it

 

[Fabrimacator21]

Looks like you might not have enough angle on the axle. I know if your ujoint doesn't have enough angle you can get vibrations.

Did you lengthen the driveshaft? I'm running a 6" lift with a 241 and stock pinion location with no vibes at 70 mph. Just had it lengthened an inch or so. It was barely drivable with the stock driveshaft. Actually vibrated so bad it wore out he grooves in the yoke where the ujoint sits. Had my ujoint come unstrapped at 65 mph.

I believe it was 200 for a new yoke installed and the longer driveshaft.

 

[blazerboss 85]

I know if your ujoint doesn't have enough angle you can get vibrations.

no $hit! im gunna have to look into that!!!

 

[ragedracer]

The angle is perfect for a CV. The joint at the rear axle sholdn't be pointing straight at the t-case in your set up. A shim under the leaf packs will fix it

Shim the axle so it "points" more up right? And, what degree shim would you think would be good?

 

[RaysJimmy]

A couple options. You can lower the t-case and shorten the rear shackle or get a SYE with a CV joint on top. YOu have more options but those are the first two that popped in my head.

 

[ragedracer]

A couple options. You can lower the t-case and shorten the rear shackle or get a SYE with a CV joint on top. YOu have more options but those are the first two that popped in my head.

NP208. SYE is no fun. =)

 

[ragedracer]

Did you lengthen the driveshaft?

IDK if a longer driveshaft would fix the issue. You can see from the "shiny" part on the slip yoke that it barely came out of the trans. case.

But, I dont know what I'm talking about, so you could be right. =)

 

[RaysJimmy]

There's specific angles that u-joints need in order not to vibrate (for your application). Check the link, good info. http://www.4xshaft.com/index.html

 

[RaysJimmy]

T-case

NP208. SYE is no fun. =)

Ohhhh, didn't say what t-case it was.

 

[ragedracer]

There's specific angles that u-joints need in order not to vibrate (for your application). Check the link, good info. http://www.4xshaft.com/index.html

So, from looking that link, it looks like I need to shim the axle so the pinion points more down.

Considerably more. Maybe a 4 or 6 degree shim? I couldn't find where he tells proper angles?

 

[Avery4jc]

You shouldn't need a SYE... I'm in the process of setting up my rear suspension and did a flip with 6" shackles and 57's so it's plenty flexy and my slip yoke d-shaft is going to work out fine.
Even with a fair amount of flex/droop the d-shaft doesn't seem to pull out of the TC enough to worry about.

 

[ragedracer]

You shouldn't need a SYE.snip...
Even with a fair amount of flex/droop the d-shaft doesn't seem to pull out of the TC enough to worry about.

Yeah, I think my slip yoke is fine. I put the frame on stands and let the axle hang, the shaft didn't pull out enough for me to have any concerns. The pinion angle is my issue!

 

[ragedracer]

Ah, so I did some more searching. It looks like for the happiest drive line, the pinion needs to be parallel to the TC output. So, I need to shim the pinion down. Just need to figure out how many degrees I need!

 

[Avery4jc]

The pinion angle is my issue!

I'm still confused about the reasoning behind setting up the d-shaft angle for a 2 joint shaft.... it seems to me that if the rear end pointed towards the TC (making the yoke line up with the d-shaft so it's all in line) would be better but everything I've read/heard says that's absolutely wrong...

 

[ragedracer]

Ah, so I did some more searching. It looks like for the happiest drive line, the pinion needs to be parallel to the TC output. So, I need to shim the pinion down. Just need to figure out how many degrees I need!

Quoting myself.... Ha.


Man, I love my G1 phone. I just downloaded an angle finder app, lol. Lets call my TC output zero. My pinion angle points up 13 degrees. I need to bring it to zero. Where the heck am I gonna find a 13 degree shim?

ETA: Or should I do a TC drop, and see what that gets me first?

 

[Avery4jc]

Where the heck am I gonna find a 13 degree shim?

Call Kert...

http://www.diy4x.com/suspension.htm

 

[resurrected_jimmy]

Shim the axle so it "points" more up right? And, what degree shim would you think would be good?

Put an angle finder on the joint at your T-case and your pinion needs to match that angle

 

[Fabrimacator21]

IDK if a longer driveshaft would fix the issue. You can see from the "shiny" part on the slip yoke that it barely came out of the trans. case.

But, I dont know what I'm talking about, so you could be right. =)

Remember that when you put the axle where it should be your d shaft is gonna get shorter. You might be ok... just something to keep in mind.