Shackle-Flip and measuring for Driveshaft

[ClovisMan]

Okay, got the shackle-flip installed over the weekend and went an bolted up my rear driveshaft. It will bolt up to the axle, but it is all the way out, fully extended with the trucks weight on the rear tires. How much longer does it need to be?

Fully extended the stock shaft measures 41 inches. I have a QT rear driveshaft that measures 46.25 inches fully extended and 43 inches fully compressed. Too long?

[CutterN55]

Hope I'm not off in the weeds...

the stock one is too short, and the other is too long. cut it down, sleeve it, and weld it, unless somebody comes up with a bolt in driveshaft for you.

I just cut down my new front shaft I got out of an XJ for my spring reversal. Only difference is you will have yours balanced for rear application.

The problem with a short stock shaft is on droop you will pull the shaft apart and you will have drive shafts pieces flying all around under your truck beatin' the crap out of everything. A shaft that is too long won't have any room to compress & will kill your transfer case.

The shaft should sit somewhere close to mid-slip with weight on wheels. I'd have it a little more on the compressed side (maybe 1/2") to give it a little more slip on the droop. I did that due to looking at the evidence on my stock shaft. I had less movement on the compressed side vice the droop side if that makes sense...

Maybe somebody else can give you better info...:o

[ClovisMan]

So basically I need two more inches....Great Googley MoogleyGreat Googley MoogleyGreat Googley MoogleyGreat Googley MoogleyGreat Googley MoogleyGreat Googley Moogley the story of my life!!!:D

[CutterN55]

:funny:

[J20 project]

cut it down, sleeve it, and weld it,
Well, not to be weird but lets' think about that. If he plans to have it balanced(which he should, considering it's a rear shaft), I kinda doubt a competent dshaft shop is gonna want to balance a home, sleeved shaft. Better to just take it to them and allow them to cut the end off, reinstall, and then balance.
If it's just gonna be a trail rig..maybe but we tend to spend enough time and money on these things that if you keep jury rigging everything, pretty soon you have a pile of jury rigged junk that,
A, nobody wants to give you anything for, and
B, You get tired of fighting the crap that doesn't work quite right and you lose your enthusiasm for it and eventually give up on it.
J20 project

[Casey]

Get it bolted together they way it will sit when it's finished. Then turn the t-c yoke so that it is vertical. Then do the same with the rear axle. Measure from the bottom holes on the t-c yoke to the bottom holes on the axle yoke and that is the number you'll need for a driveshafts shop to make a new one or cut one down.

I took a longer rear shaft out of something in the junkyard that had the same yokes and had it cut and balanced to fit. It was less than $100.

[CutterN55]

J20- Your are probably right about sleeving a rear shaft and getting it balanced.

I did my front at home and I had a spare in case I boogered it up. I just cut the tube at the plug, paying close attention not to go too deep and cut into the plug. Then I cut the tube down taking my time ensuring a nice straight cut. I notched the tube about 1/4" at 0, 90, 180, and 270 degrees. I stuffed the plug in there ensuring it was all nice and straight. I set it on a peice of steel plate and measured it out to be within 1/32nd. Thats gotta be as good as stock... Then I filled the notches with weld and butt welded the seam like it comes from the factory.
Then I ground down my welds looking for cracks and pockets(found none) and burned it again.

I haven't balanced mine, but I've driven the highway with the front hubs locked and I feel no vibes at all. It may not be perfect, but I took my time and wouldn't call it jury rigged.

http://i899.photobucket.com/albums/ac193/Cuttern55/War%20Wagon/0731101017.jpg

[J20 project]

Cutter, please don't take offense w/ my terminology. We see so many new, inexperienced mechanic/wheelers come on here that we tend to take for granted that they will have a skill set which allows for them to do what some vets do. That is not the case, sometimes the difference in continuing a hobby has more to do w/ personal success than anything else. Some things are better left to the pros while these guys are learning.
I too have been building my own shafts for years..Rear shafts also. If I had a lathe right now, I wouldn't even think of letting someone else touch one. I don't, so things like my daughters KJ front shaft got taken to a shop.
My J20 is another story.
Keep wheelin....FULLSIZE!!
J20

[ClovisMan]

Get it bolted together they way it will sit when it's finished. Then turn the t-c yoke so that it is vertical. Then do the same with the rear axle. Measure from the bottom holes on the t-c yoke to the bottom holes on the axle yoke and that is the number you'll need for a driveshafts shop to make a new one or cut one down.

I took a longer rear shaft out of something in the junkyard that had the same yokes and had it cut and balanced to fit. It was less than $100.That's some good stuff there Casey. Thanks!:thumbsup:

[CutterN55]

Cutter, please don't take offense w/ my terminology. We see so many new, inexperienced mechanic/wheelers come on here that we tend to take for granted that they will have a skill set which allows for them to do what some vets do. That is not the case, sometimes the difference in continuing a hobby has more to do w/ personal success than anything else. Some things are better left to the pros while these guys are learning.
I too have been building my own shafts for years..Rear shafts also. If I had a lathe right now, I wouldn't even think of letting someone else touch one. I don't, so things like my daughters KJ front shaft got taken to a shop.
My J20 is another story.
Keep wheelin....FULLSIZE!!
J20

No offense taken J20, and I understand what you are saying completely. I'm not a vet FSJ guy or mechanic by any means, but I'm decent with wrench and like to take a crack at F.U.B.A.R.'ing something real good before I'll pay somebody else to do it. I love getting feedback from the experienced guys, because the last year or so I've been on here, I have learned a TON! I'm always wanting to learn how to do things better and not pay out the nose. I appreciate your comments.