There must have been a reason they went to the Rzeppa’s on the JKs. Is this it?
Harmonic vibrations in Jeeps: A new theory (please read!)
- Thread starter psrivats
- Start date
Pressurized
TJ Enthusiast
Is the concern on the Rzeppa the short shafts we have on the TJ's? Is it possibly better on an LJ? I know I was told that most CV's will cook the boot at highway speeds with too much angle on them. But that's what the high angle Rzeppa's are supposed to be good at, right?
Something like the photo below built with Yoke adapters... Can we get an adapter for both ends? Now, since we only have the problem when BOTH shafts are spinning, is it possible that just one of these would fix the problem? Is it strong enough? Would the rubber boots survive?
I know places like Tatton's sells an Rzeppa front for the JK, but it's just 1 Rzeppa. Seems like to solve this, it would need to be both ends.
Something like the photo below built with Yoke adapters... Can we get an adapter for both ends? Now, since we only have the problem when BOTH shafts are spinning, is it possible that just one of these would fix the problem? Is it strong enough? Would the rubber boots survive?
I know places like Tatton's sells an Rzeppa front for the JK, but it's just 1 Rzeppa. Seems like to solve this, it would need to be both ends.
Pressurized
TJ Enthusiast
I see the YA WU-07, but it says 27 spline axle. I thought the Rubicon Dana 44 was a 30 spline? If so, that's the YA WU-08 and it's the 5x5.5... Yuk.
Inner is 30 spline, outer is 27 on the rubicons. So the WU-07 will work fine (infact you get an aftermarket chromoly outer shaft with the kit). One thing to be aware of this kit is that the front track width widens by 3/4".
The WU-08 kit gives you 30spline outers as well, in addition to being a different bolt pattern. No change to track width.
Pressurized
TJ Enthusiast
JB conversions makes an adapter. I really looked into this before I decided hub kit was the easier (and better) solution.
http://www.jbconversions.com/products/yokes_flanges/1961.php
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Pressurized
TJ Enthusiast
Pressurized
TJ Enthusiast
I see they have both front and rear... The downside is this is also $1000+ but a lot less to install. But it's not a guaranteed fix, where the free spin hubs seem to have a high degree of success.
I haven't read through all of this thread yet, but if a couple of you guys don't mind, please check out my thread and some of my thoughts on setting my pinion angle. Am I off base on this or does my logic fit the situation?
https://wranglertjforum.com/threads...pinion-angle-with-a-3-lift.43223/#post-724344
https://wranglertjforum.com/threads...pinion-angle-with-a-3-lift.43223/#post-724344
Pressurized
TJ Enthusiast
There are typically 2 setups on our driveshafts... If you don't have a double cardan style driveshaft, you want your TC output shaft and your differential input shaft to be parallel. Typically when you lift, your diff rotates your pinion upwards a little. So it would require some adjustable lower control arms to be able to reset those shafts to parallel. Depending on how high you lift, your driveshaft may not be able to handle that extra length that is required to make that adjustment.
With a double cardan, you want the driveshaft and the differential input shaft to be inline... Zero degrees. Since lifting typically rotates the pinion up and the stock driveshaft may not be able to handle the corrections needed, the double cardan driveshaft replacement is the popular choice...
Thank you. That is what I thought was happening, but I was getting confused by comments in the other thread.
I already have adjustable control arms. So maybe I will just extend the lowers a little to see if I can get everything back to parallel. What is the best way to tell if my stock driveshaft can handle the extra length. Does anyone know the maximum length that it can handle?
If you are concerned that the wider track resulting from using the YA-WU-07 kit will require you to use spacers, etc. in the rear or different backspaced wheels, or some other means to equalize the track front and rear, don't be. Many people have installed this kit without any of those workarounds and without any issues and it has been relatively plug and play for them.
At least one TJ suspension/steering expert finds the wider track in the front to be a positive rather than a negative. If fact, had I talked to him more before I purchased my YA-WU-08 kit I might have gone the other way.
Pressurized
TJ Enthusiast
Not worried about the difference in F&R... Confident that the tires would hit the fenders. I was extremely careful to make sure I could tuck the tires. It would cause me to need fenders.
Pressurized
TJ Enthusiast
After going through the list of disconnecting and/or removing various components, I found that with the front driveshaft disconnected at the input shaft, it ran smooth as silk up to 85... It was the best combination. So that tells me the free spin kit is the best solution. I'll just have to deal with fenders if it does create an issue.
Anyone in here have any ideas on vibrations that i am trying to track down. 2006 Unlimited Rubicon 6spd, factory 4.10 gears, 3.5" Lift.
Here is my thread I started
https://wranglertjforum.com/threads/vibration-starting-at-70-mph-after-new-parts.47005/#post-805923
Here is my thread I started
https://wranglertjforum.com/threads/vibration-starting-at-70-mph-after-new-parts.47005/#post-805923
blcoonrod
New Member
04 Rubicon, 5 speed, 5:13 gears, 4.5" lift, 1.25BL, 37's, Adams Shafts, Savvy Control Arms.
Bought the jeep with worn out Skyjacker springs and control arms, worn Toyo 37's, worn out tierods, trackbar and ball joints, 4:88 gears. Oh and did I mention speedo doesnt work. But got a good deal. No vibs what so ever.
Upgraded all the steering components and ball joints. Still no vibes.
Bent a rear axle and had a leaking front axle seal so figured it was time for some work.
Installed Savvy Control arms, Yukon 5:13 gears, 4.5" Krawler springs, Bilstien shocks, Adams CV driveshafts, fixed work motor and transmission mounts, new revolution rear axles, and one new front right axle.
After the install I got the dreaded 65+ harmonic vibe/drone. I have double checked gear set up, set front and rear pinion angles at many different angles with no change. Then stumbled across this thread. This Jeep is driving me crazy, sometimes wish I had my old YJ back. I'm not going with manual locking hubs as a bandaid. I suppose im going to experiment with the TC balancer weight or removal first, then do a heavy Skid plate. Been wanting to do a tummy tuck anyway.
Bought the jeep with worn out Skyjacker springs and control arms, worn Toyo 37's, worn out tierods, trackbar and ball joints, 4:88 gears. Oh and did I mention speedo doesnt work. But got a good deal. No vibs what so ever.
Upgraded all the steering components and ball joints. Still no vibes.
Bent a rear axle and had a leaking front axle seal so figured it was time for some work.
Installed Savvy Control arms, Yukon 5:13 gears, 4.5" Krawler springs, Bilstien shocks, Adams CV driveshafts, fixed work motor and transmission mounts, new revolution rear axles, and one new front right axle.
After the install I got the dreaded 65+ harmonic vibe/drone. I have double checked gear set up, set front and rear pinion angles at many different angles with no change. Then stumbled across this thread. This Jeep is driving me crazy, sometimes wish I had my old YJ back. I'm not going with manual locking hubs as a bandaid. I suppose im going to experiment with the TC balancer weight or removal first, then do a heavy Skid plate. Been wanting to do a tummy tuck anyway.
In 35 pages of theories, has anyone theorized about the offset of transfer case mount?
Stock skid pushes it to the right, which creates additional angle between pinion and drive shaft.
Stock skid pushes it to the right, which creates additional angle between pinion and drive shaft.