Rear yoke problems

[LittleD]

My friend has been having problems with his jeep breaking yokes in the rear of his xj. He went to flex on a tire, the lsd locked in his rear and snapped the yoke on his 8.25 into pieces. I did some research and saw that shims may cause the pinion to be set to high, and under certain conditions (flexing, heavy acceleration) the rear gets bad axle wrap causing the u joint to bind and break things. He is running i think a 6 degree shim that came with his lift. Is this a common problem?

Any suggestions are greatly appreciated.

[wannabejeep]

jeepin josh?

[OWEN]

Here's what I did on mine

[iant333]

My friend has been having problems with his jeep breaking yokes in the rear of his xj. He went to flex on a tire, the lsd locked in his rear and snapped the yoke on his 8.25 into pieces. I did some research and saw that shims may cause the pinion to be set to high, and under certain conditions (flexing, heavy acceleration) the rear gets bad axle wrap causing the u joint to bind and break things. He is running i think a 6 degree shim that came with his lift. Is this a common problem?

Any suggestions are greatly appreciated.

I've broken 2 yokes on my 8.25 in the past month due to 33's on the stock gears, what is his geared to and what size tires does he have? If its geared too high (Big tires with stock gears) it puts way too much strain on the driveline and will break stuff. If thats the issue it just has to be geared lower.

I've heard of it happening due to incorrect driveline angles as well but I dont kn ow what to tell you as far as fixing it there.

[TheDude]

Incorrect drive line angles are the cause for yoke binding and detonation. Use an angle meter to find his stationary angle and adjust accordingly. Chances are good he is at his "torque applied angle" which would be the cause of all the carnage. This would be especially so if the XJ does not have an sye. I would be less weary of stock gearing and over-sized tires. Other than its lack of get up and go they would contribute less to a yoke failure than having your pinion face more than 4* off location.

Easy solution, measure the pinion angle with said angle finder, ensure his u joints are the correct cap size and are in functioning order prior to having issues, adjust pinion angle with more or less wedge. Having even 4.5" of lift without an sye or a drop kit is problematic on drive line components.

RM

[iant333]

Incorrect drive line angles are the cause for yoke binding and detonation. Use an angle meter to find his stationary angle and adjust accordingly. Chances are good he is at his "torque applied angle" which would be the cause of all the carnage. This would be especially so if the XJ does not have an sye. I would be less weary of stock gearing and over-sized tires. Other than its lack of get up and go they would contribute less to a yoke failure than having your pinion face more than 4* off location.

Easy solution, measure the pinion angle with said angle finder, ensure his u joints are the correct cap size and are in functioning order prior to having issues, adjust pinion angle with more or less wedge. Having even 4.5" of lift without an sye or a drop kit is problematic on drive line components.

RM

Not to hijack, but in my case everyone I had talked to said it was due to my gears, however I don't have an SYE, I have a 3.5 inch rear lift and its shimmed so that the pinion points directly at the output shaft, its been like that since I installed my shackles. I figured it would just be less trouble for me when I get an SYE and never bothered re-shimming it, but is that's whats killing my yokes you think and not the gears?

[Burton58]

i broke my old 8.25 yoke 3 times with shims and 4.5" of lift. took em out, never broke one again

[Customjob]

Here's what I did on mine

that doesnt help, there's not even a driveshaft in there

[hippie metal]

why cant josh post up his own shit?

[LittleD]

why cant josh post up his own shit?

just trying to help, and i know his area didn't have power yesterday

[hippie metal]

When did brookfield lose power? It wasnt even that bad out yesturday, I was working outside all day and thought the weather was beautiful. Then driving home, I saw shit all over the road......I dont get it

[Even]

The wind was rediculous.

A tree snapped in half in my backyard, and my buddy almost drilled a huge tree limb downed in the road on our way to NY to pick up booze.

[WAD357]

I used to break yokes on my 35 every time I went out... I mean I know it was a 35 but I think my rear was overshimmed... after setting the pinion angle correctly on the 8.8 I havent had a single driveshaft issue...

[TheDude]

Not to hijack, but in my case everyone I had talked to said it was due to my gears, however I don't have an SYE, I have a 3.5 inch rear lift and its shimmed so that the pinion points directly at the output shaft, its been like that since I installed my shackles. I figured it would just be less trouble for me when I get an SYE and never bothered re-shimming it, but is that's whats killing my yokes you think and not the gears?

Yes I honestly do. Incorrect drive line angles are certain death for any joint and its misc parts when calculating speed to drive line rpm's. I would measure everything after lifting any vehicle to ensure the angles are correct. The problem lies with acceleration and torque causing the axle housing to lift. This lift is an issue especially with leafs and even more so being sprung over. You do not want that yoke and u joint to hyper extend itself in relation to the drive shaft or the transfer case. lower degree shims will allow torque to be applied causing said "lift" of the housing which in return aligns the yoke to drive shaft eliminating bind. I'm not saying use a tape measure and drop the angle severely, just factor in axle twist and you should be set. Leaf springs are like spiteful women when setup incorrectly, they can break your heart and empty your wallet.

RM

[TheDude]

For those with add...

Basically the axle is over shimmed and hyper-extending past the yoke and joints limit. Calculate axle twist into your pinion angle when drive line torque is applied for correct angles and all yoke issues should be a thing of the past.

With a SYE you want the drive shaft to be parallel with the pinion face, otherwise you want them on opposite yet almost parallel paths within 1-3* such as this:



RM