OP
Re-geared, now I have a vibration above 50 mph
- Thread starter bobthetj03
- Start date
well i'm jumping onboard here because I'm having the same problem. Right now I'm running pinion angle 1 degree lower than drive shaft angle and starting around 50 mph I get the vibe. Its like a phone ringing in your pocket vibe that wasn't there before. I just changed out my lift from a 4" skyjacker to a 3.5" RocKrawler. Added an sye and new driveshaft. I didn't have the vibe before the change. I've tried every angle from dead on to 3 degrees higher and lower in 1/2 degree increments. I haven't tried removing the front drive shaft yet. Going to try that today probably and then wait and see what you all come up with.
jeepndogs
TJ Enthusiast
I really don't think you are doing anything wrong. I think it's the combination. I have two guys local to me in two different jeep clubs that have the same exact thing going on. With the driveshaft speeds these things have with the taller gears things get crazy. A local driveshaft guy told me if he built a 2 1/2 heavy wall shaft for it it would fix it, but it will not clear the rail for the trans pan.
OP
I hope you get it worked out, because I know it can be frustrating, just trying to get the Jeep right, and thinking you've done everything right and everything you know and keep searching. It's no fun when it's not working. I hope its wheels/tires.
OP
In those pics, are the u joint straps tightened down or loose? There looks to be large gaps between them and the yoke.
OP
Yes, they are cinched down tight. I bought a new strap kit when I got the new drive shaft, but I will re-visit that tomorrow.
Good luck with the tire and wheel swap. Hope you can get something figured out. This has got to be driving you nuts! No fun when things aren't working right.
So they are tight and have that gap? I have never seen one with gaps, they always fit flush. Not saying that is your problem, just that it should be addressed.
Did you ever swap out the tires with your buddies jeep? I am kind of agreeing with Chris's original reply. Maybe when they did the swap they lost a wheel weight? It sure sounds like tires to me. Again it is hard to diagnose over the internet, but swapping tires with your buddy is a free test, and pretty easy too if you have air tools. At least a cheap easy way to rule something out. Another test is that you feel like it is coming from the rear. Try rotating your tires, and see if you can feel it in the front.
Concerning the u-joint straps: that is not normal. I don't know where you got that kit from but I've never seen those types or bolts or straps so short like that. I would go to the parts store and buy the regular strap and bolt kit from behind the counter and install those. Not that it'll fix the problem, but those should not be installed like they are in your pictures.
OP
You know, It didn't seem right to me either. I bought the strap kit from Napa Auto per application. First thing that threw me off is the kit bolts were 5mm allen heads. Didn't like that off the bat. So, I just put my old straps back on and I like this much better. Didn't cure my vibes, but that could have been a whole other issue altogether.
OP
Thanks LR. We'll see what the tire swap nets tonight.
Yep, didn't seem right to me either, so I put my old straps back on.
Heading to my buddy's tonight to do the swap.
OP
Tire swap results: no change, cyclic vibes still there. I do have to mention however, the KO2's ride so much smoother and quieter. Definitely going to be my next tire. I'm done with MT's.
I don't want to talk trash on Adams shafts, but here is one thing I'll say...I have had issues with mine in my YJ. My first one was balanced imperfectly slightly and so about 40-55 or so it would vibrate noticeably. It got a little better at highway speed but still not perfect.
Now, James has outstanding customer service and got me another shaft like he got you (I think I remember you saying that). That one worked well for me at first, but it did have a slight vibration at 75-80 out of the box. I typically cruise at 75 here on Texas highways so it was noticeable for me. I decided to live with it, they were better than my vibes had ever been.
I recently moved to Dallas (3.5 hours away from where I was previously, in College Station). The day before I moved, I drove both ways to do some stuff for my new apartment. That's about 450-475 miles of driving. The Jeep performed pretty great considering the distance and the fact that the vibes were easily not a big enough deal to be on my mind. Then, the next day, I removed my driveshaft (liability purposes though U-Haul) to tow the Jeep back out to Dallas on a U-Haul dolly.
Ever since that day, I have had horrible vibrations from 40+. You can hear the u-joints humming easily. I don't even have my front shaft installed and they don't spin on YJs anyways so I know it's something with my Adams shaft. Who knows why, nothing changed with that shaft but now it's giving me issues. The u-joint caps were taped tight and the driveshaft was gently carried in my mom's car. I have rotated the u-joint positions on both yokes separately so the shaft has been reinstalled in every possible way that it can be.
I don't want to really bother him for another shaft, I'm strongly considering going to Tom Wood and just buying one from him. It surprises me because so many people have great experiences with Adams but for some reason, I haven't. Just something to think about.
Maybe find a TJ or YJ buddy around you (with an SYE, of course) and steal their CV shaft for a few minutes just to see what happens. I don't really know what else to tell you, I'm at a loss.
I should add...4.0, 5-speed AX15, 31's, 4.10 gears. I'm geared basically the same as your 4.56 and 33's.
Now, James has outstanding customer service and got me another shaft like he got you (I think I remember you saying that). That one worked well for me at first, but it did have a slight vibration at 75-80 out of the box. I typically cruise at 75 here on Texas highways so it was noticeable for me. I decided to live with it, they were better than my vibes had ever been.
I recently moved to Dallas (3.5 hours away from where I was previously, in College Station). The day before I moved, I drove both ways to do some stuff for my new apartment. That's about 450-475 miles of driving. The Jeep performed pretty great considering the distance and the fact that the vibes were easily not a big enough deal to be on my mind. Then, the next day, I removed my driveshaft (liability purposes though U-Haul) to tow the Jeep back out to Dallas on a U-Haul dolly.
Ever since that day, I have had horrible vibrations from 40+. You can hear the u-joints humming easily. I don't even have my front shaft installed and they don't spin on YJs anyways so I know it's something with my Adams shaft. Who knows why, nothing changed with that shaft but now it's giving me issues. The u-joint caps were taped tight and the driveshaft was gently carried in my mom's car. I have rotated the u-joint positions on both yokes separately so the shaft has been reinstalled in every possible way that it can be.
I don't want to really bother him for another shaft, I'm strongly considering going to Tom Wood and just buying one from him. It surprises me because so many people have great experiences with Adams but for some reason, I haven't. Just something to think about.
Maybe find a TJ or YJ buddy around you (with an SYE, of course) and steal their CV shaft for a few minutes just to see what happens. I don't really know what else to tell you, I'm at a loss.
I should add...4.0, 5-speed AX15, 31's, 4.10 gears. I'm geared basically the same as your 4.56 and 33's.
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OP
Thanks for your input. I've about run out of solutions at this point, so you could be right about it. There isn't much more I can do, but I might consider taking the rear drive shaft out and take it to a good drive shaft shop to have it checked out. I told James Adams I was going to do that when I suspected his front drive shaft wasn't balanced proper, and he sent me a replacement ASAP, but like you said, I don't know if I want to bother with him yet again and be "that guy". The other thing I'm considering is the possibility that the ring gear in the rear diff is warped. Rob, what do you think about that possibility? Could one pull the cover, put a dial gauge on it and check it for run out? Another possibility could be a bent axle shaft maybe? Like I mentioned earlier, while I was waiting for the rear drive shaft to arrive, I drove the jeep home with just the front drive shaft, and no vibes at all, so I'm leaning to the rear as the culprit. I have not tried pulling the front drive shaft out yet after doing the SYE, so I may try that next to verify it isn't the front.
OP
Oh, and pics or it didn't happen, right?
Birddog's with 285/75/16 KO2's. Those Birddog's are frickin heavy! My back is feeling it today.
Birddog's with 285/75/16 KO2's. Those Birddog's are frickin heavy! My back is feeling it today.
jeepndogs
TJ Enthusiast
I would pull the front shaft and take it for a ride. I think you will find it goes away. I can be vibration free with ONE shaft in, doesn't matter which one it is. Vibration only happens if I have both shafts in, I believe it's a harmonic issue with both shafts spinning.