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View Full Version : JK Wrangler Driveshaft U-Joint Failure



SnakeDoctor
24-02-19, 08:48 PM
All,

My front driveshaft u-joint has been giving some vibrations on and off and definitely has visible slop in it, so I should replace it before it falls out, a new driveshaft from USA is approximately 1K AUD Delivered (+ whatever taxes they hit me with) which is obviously a bit more than an aftermarket tom woods etc style.

Has anyone had one rebuilt in Sydney? Google search says they aren't serviceable.

Does anyone have a spare laying around (take-off from an upgrade)?

The CV boot seems to be in good condition.

I'm not sold on aftermarket driveshafts with AEV suspension but i'm guessing there's lots of them getting around.

Dru
25-02-19, 09:51 PM
All,

My front driveshaft u-joint has been giving some vibrations on and off and definitely has visible slop in it, so I should replace it before it falls out, a new driveshaft from USA is approximately 1K AUD Delivered (+ whatever taxes they hit me with) which is obviously a bit more than an aftermarket tom woods etc style.

Has anyone had one rebuilt in Sydney? Google search says they aren't serviceable.

Does anyone have a spare laying around (take-off from an upgrade)?

The CV boot seems to be in good condition.

I'm not sold on aftermarket driveshafts with AEV suspension but i'm guessing there's lots of them getting around.

Is there a reason to think it is the shaft not the Uni joint? Generally look to replace the universal joint then re-align when you put it together. I try not to replace a shaft unless I break it or i'm looking to increase the spline count.

SnakeDoctor
26-02-19, 06:54 AM
Is there a reason to think it is the shaft not the Uni joint? Generally look to replace the universal joint then re-align when you put it together. I try not to replace a shaft unless I break it or i'm looking to increase the spline count.


Thanks for the reply Dru, it's definitely the uni-joint on the front driveshaft, (transfer case to the front axle), it's broken enough that even a mechanical potato like myself can confirm [moves in/out, metal shavings hanging out of it, clunks, etc].

I spoke with Jeep Konnection who do lots of AEV suspension lifts and whenever they swap out the driveshaft they replace it with the Tom Woods unit so i'm more comfortable going down that route and have ordered a replacement, the notes on the Tom Woods and other sites in regards to pinion angle (adjustable upper control arms) being critical for smooth operation might be less applicable in this scenario.

Dru
28-02-19, 01:00 PM
SO there are a couple of items there.

1. The Woods shafts are fabulous but I wouldn't personally bother changing unless there was damage (not just the Uni J) or more likely for increasing the spline count (just means bigger diam shafts). It won't hurt but I don't see the need.
2. The Uni J will fail for any number of reasons not just because of a shaft issue. Actually I understand that the Uni J is intentionally designed as the point - it's a lot cheaper replace than breaking something else. Most common cuase of fail is to do with alignment through the joint - "pinion".
3. Pinion is adjustable if you have adjustable control arms. Also with adjustable control arms caster is adjustable. What is NOT adjustable is the angle between pinion and caster (or you replace the diff as it is a manufactured in angle). Sometimes it means you end up looking for a compromise between the two and live with wearing through the Uni J.

Hope that makes sense and btw I am no expert so happy to be corrected by anyone with input.

Dru

SnakeDoctor
15-02-20, 10:28 PM
Have been running the woods shaft for a while, it's OK but definitely not as smooth as the OEM (or no shaft).

It's also worked itself loose (I picked this up on inspection prior to a Vic High Country trip).

Not convinced I made the right call here, i'll keep an eye out for an OEM or upgrade the suspension / go back to swapping out the front axle like i had planned to/purchased for a long time ago.

SnakeDoctor
16-03-20, 07:27 PM
Folks, it's definitely worth checking all the installs and learning how this all works.

Just measuring my pinion (+ caster) angles and i've worked out that the installer used the wrong height holes (control arm drop brackets) and i've been running stupid caster (too much) and a really bad pinion angle ever since I got my original lift.

I'm sure this didn't help with the increased wear on the driveshaft and then the diff (which I just had overhauled).