How high before bind?

[Cresso]

Grrr, stupid bulletin board forgot who I was and erased my message. Attempt #2....

I have an XJ at about 7-7.5" of lift right now. It has a SYE and CV-style rear driveshaft. I'm planing on lifting a little more. Somewhere in the 8-10" range. I'm also hoping to raise the xfer case a tad (about an inch). At what point, assuming stock rear axle location, will I run into u-joint bind on the rear shaft? Has anyone here actually run in to the point with a SYE/CV shaft? Any and all advice welcome! well, any except "lower your xj". hehe

 

[daytripper]

How about trimming your fenders (if you havent already) it will keep your center of gravity lower and allow for more tire stuff room?

 

[Cresso]

Already trimmed tons, thanks. Just looking for the driveshaft info.

 

[XJoachim]

I'm at 12' rear now and it's hard to keep a CV quiet at this heigth. At 8' i had some vibration which i think came from the too large u-joint angles. I had driveshaft lengthened and no play in the u-joints, perfect angles and still that small vibration. SYE was already in the plans so i upgraded. Now at 12' rear i'm more fighting axle wrap which leads to bad u-joint angles.

A different story for the front, i have a vibration there since i went to 10'. I already have a new drivesahft for the front and will replace pinion bearings and t-case output bearings and hope tu cure them.

 

[bgcntry72]

12 feet of lift.........impressive. What is your method of entry? Are you airlifted? Elevated? even at a moderate 8 feet of lift, as you had earlier, I see a problem with bumper height, to say the least.

 

[Neil]

How do you use the drive through a Mickey D's?

 

[ashmanjeepxj]

The real question is:
What is the maximum angle on a 1310 double carden joint?

Your probibly running the same double carden joint front and rear and since the front drive shaft is shorter your front will bind first.


So who knows the max angle on the double carden?

 

[ZPD]

How about pulling your driveshaft out and see what the maximum angle would be? Seems like a simple method to finding the answer

 

[ashmanjeepxj]

How about pulling your driveshaft out and see what the maximum angle would be? Seems like a simple method to finding the answer

At different degress of rotation the U-joints will have different max angles.

If you found the max angle while spinning the drive shaft, you should then add a safety margin, and we will have our answer.

So how many degrees of margin would be needed.

Its obvious that the Ujoint will show vibrations at high angles before it is fully mechanically binding like you could test for by hand.

So we want to know two things, how much angle with no vibes at high RPMs, and max angle for low speeds with no mechanical binding, like slow crawling where vibes are not a concern only binding?

 

[Cresso]

Yea, the max angle would be the ideal measurement. That'd do, but since I lack an angle finder, I'd also like a ballpark lift meaurement as well. Looks look XJoachim is at 12" without problems, so that's really good news.

EDIT: I hate it when I'm dumb even though I should be used to it by now. There's a million ways to use household items to figure out the angle of my driveshaft, so that's no excuse. That said, I'd STILL like to hear more experience per lift height, not just max angle. Solid numbers are great to have, but we all know the practical application often emulates but rarely perfectly matches the theoretical absolute.

 

[ashmanjeepxj]

I lack an angle finder

Do you get the harbor freight tools catalogs, they have a cheep $7 angle finder, its even magnetic, I like mine.

 

[XJoachim]

Yep, as you said it is harder to fight the front angles. I have a small vibration in front because i have to rework the upper connecting arms of my long arm kit so they give room to rotate the pinion up a bit more.

The angles at 12" are not that bad and i still can flex my front to the extreme without any binding in the CV.

Don't worry about working angles of CVs in a XJ.

 

[Nay]

CV Angle & High Pinion Rear

The max recommended continuous operating angle for a CV joint is about 22 degrees. Without additional clearancing (grinding), it will bind at about 28-30 degrees.

The absolute best thing you can do if you want to run at 10" of lift and it isn't a trailer queen is to get a high pinion rear axle, and I'd get a D60 considering I'd imagine you are looking to run 38" tires.

I have a Currie high pinion 9" (reverse rotation Ford 8.8 in a 9" housing) with 8" of lift. My t-case is raised about 3/4" above the stock location, and my CV operating angle is only 15 degrees. It was 20 degrees prior to the high pinion rear. It drives smoothly at 70 mph (and I won't drive it any faster) with zero noise and zero vibration. The axle is designed for extra pinion bearing lubrication, as would a high pinion 60.

At 10" of lift with a high pinion, you would have a continous operating angle of about 18-19 degrees even with your raised t-case - this is within tolerance and it should drive smoothly. Plus you get that driveshaft up and out of the rocks...definitely the way to go if you want the best of both worlds.

Nay