OP
Good info. Will keep playing around with the pinion angles and maybe check my CA's again. You might be on to something.
Re-geared, now I have a vibration above 50 mph
- Thread starter bobthetj03
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Good info. Will keep playing around with the pinion angles and maybe check my CA's again. You might be on to something.
I believe in that thread, what finally fixed it for the OP was replacing his tranny mount, and the bolts on his control arms. He had re-used the oem bolts for his RK lift, when a slightly larger bolt was required. Replacing those seemed to have done the trick. Whether all this applies to your situation or not, some good ideas...
OP
My trany mount seems solid, but at 151K miles it couldn't hurt to change it, and it's not a lot of caps. I changed all my control arm bolts to grade 8 hardware when I installed the Cloaks, but it couldn't hurt to check torque and maybe pull one at a time to inspect for wear. I'm wearing out my cardboard creeper, lol!
New to the forum, signed up just for this thread. I don't have a solution unfortunately, but my situation is uncannily similar.
'03 TJ, Regeared to 4:56, brand new Tom woods front driveshaft, replaced axle shaft u joints, pinion yoke, ball joints, rebuilt t-case with new chain, new transmission mount, MC adjustable front lowers, Teraflex super short SYE with an Adams driveshaft turning an ARB locked 8.8 in the rear.
My vibe starts around 65. Below 65 it's smooth. Goes away when the front driveshaft is removed. Had a tiny bit of play in the front t case output, rebuilt it. Had the stock ds balanced and rebuilt, then replaced it Had a tiny bit of u joint play on the front pinion yoke, replaced it. Bad tranny mount, replaced it. Front pinion angle is within 1° of the ds, vibe doesn't seem to change much with change in angle.
I'm planning to pull the front axle back apart and double check my backlash, tooth pattern and pinion preload sometime in the next couple weeks just to rule it out.
There seems to be a million threads on lots of forums describing similar vibrations with no solutions. Hopefully we can figure this out someday.
'03 TJ, Regeared to 4:56, brand new Tom woods front driveshaft, replaced axle shaft u joints, pinion yoke, ball joints, rebuilt t-case with new chain, new transmission mount, MC adjustable front lowers, Teraflex super short SYE with an Adams driveshaft turning an ARB locked 8.8 in the rear.
My vibe starts around 65. Below 65 it's smooth. Goes away when the front driveshaft is removed. Had a tiny bit of play in the front t case output, rebuilt it. Had the stock ds balanced and rebuilt, then replaced it Had a tiny bit of u joint play on the front pinion yoke, replaced it. Bad tranny mount, replaced it. Front pinion angle is within 1° of the ds, vibe doesn't seem to change much with change in angle.
I'm planning to pull the front axle back apart and double check my backlash, tooth pattern and pinion preload sometime in the next couple weeks just to rule it out.
There seems to be a million threads on lots of forums describing similar vibrations with no solutions. Hopefully we can figure this out someday.
OP
At least yours doesn't start till 65mph. Mine kicks in at 50. By chance, have you pulled your rear drive shaft and run the front in 4hi to see if you still have vibes to rule out the rear?
It's not backlash or pinion depth. Another member here found the only solution to be new locking hubs for the front end. Expensive, involved, and new rims needed but the vibrations went away. The assumption is the two drive shafts are working against one another.
When this vibe first showed up it was around 45 and got much worse with speeds above that. As I've replaced stuff it's seemed to move up incrementally.
I haven't pulled the rear shaft, but now that you mention it I'll try that tonight.
OP
Funny you should mention that, I've been systematically replacing stuff from the front axle back, and each time I change something, the intensity of the vibes lessons a bit. At first I thought it was the front drive shaft, so 3 drive shafts later I decided to pull the rear shaft. Low and behold, the vibes were almost gone when I did that, so now I'm focusing on the rear. After doing the SYE and rebuilding the transfer case with new Adams CV drives shaft, it appeared the vibes shifted to the rear. I had Currie lower arm in the rear, so I removed them and put my factory lowers back on, and the vibes got better yet. I still want to replace the trany mount and rear track bar to rule them out. Just trying to find every piece that could transmit NVH to the body. Next will be a new rear yoke, then take the rear drive shaft to a professional shop to have it precision balanced. Then, give up.
Rob may have something as to the combination of both drive shafts and the perfect storm if you will, creating this ridiculous vibe condition. My fear is when the hard top goes back on next week, the vibes become more noticeable and will likely drive me insane.
This all started for me a while ago when I heard a loud bang on the highway. Found a nice dent in the floorboard, took a while to figure out that one of the weights on the factory ds flew off. Soon after the bang, but before finding the cause, I had a leaky front pinion. Found the spot where the weight was and pulled the shaft. Decided it was time to regear since I had to tear it down anyways. Regeared the front but left the ds out because the rear was still 3:07 and I was building an 8.8. Swapped in the 8.8 but still left the ds out because I knew it was out of balance. Brought it to the only local ds shop and had it balanced, but the shop was kind of shady and I never felt confident that they balanced it correctly which is why I finally just bought a new one. Over this entire time period I would replace, repair, adjust things and throw the front ds in to take it for a test drive, then end up pulling it back out and going back to the drawing board. I've gotten pretty good at getting those bolts off the front t case yoke.
I am having trouble wrapping my brain around how both shafts would cause the vibe I'm getting. It's clearly coming from the front. Isn't the front t case yoke isolated when in 2wd? The jeep is smoother than it was when I bought it without the front ds.
I've replaced everything in the front driveline except the axle shafts, which makes me wonder. I was in a fender bender this spring. A guy crossed into my lane head on at an intersection. Low speed, the only damage to my jeep was a broken lower control arm bracket, which I replaced with boxed 1/4 thick brackets from artec industries. The hit was on the driver side, so the short shaft side. After all this vibe bs it made me wonder if that shaft could be bent or something and causing the vibes, which are then only felt with the ds in? That lead me to wonder if maybe the long side shaft being out of balance could cause this? Everything is spinning much faster with the taller gears, faster than intended from the factory. Could the tolerances in the axle shafts be too large for the rotational speeds they're seeing now? (Edit: I realize after typing this that the axle shafts are seeing the same rotational speeds they've always seen, the only things that are spinning faster is driveline after the pinion...so maybe this whole thought is null) I guess I could pull one and put it up on a lathe and try to measure runout...but that's a lot of work for such a longshot. I'm definitely grasping at straws at this point, but it's not something I've seen mentioned or considered anywhere so who knows.
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If you were hit hard enough, that's a definite possibility, yes.
This reminds me of an old VW Corrado I had back in the day. I got hit from the side at about 10 mph by another car. It didn't do much damage and I had it all fixed. However, I always wondered why ever since the accident the vehicle would sort of "crab walk" on the highway. What I mean by that is that is wouldn't drive in a straight line without effort (though it was subtle), and it had a very small vibration in the rear. I tried forever to figure out what it was. Turns out it was a bent stub axle on the side that had been hit. You would have never known by looking at it, but when I removed it and put it on a flat surface, you could tell that it was just slightly bent (I mean really slightly). But that there was enough to cause the vibration / tracking issue.
OP
Well, hope you can isolate it. I thought mine was in the front too, but it has seemed to have migrated to the rear after doing the SYE. Still would like you to pull the rear shaft and take er for a spin just to rule it out.
Whelp, took it for a spin with only the front ds in and it's still vibing. It's a little less pronounced, but still there.
OP
I've been chasing a vibration for a couple of months. My TJ is stock, not lifted, with 225/75R15's on it. Last year I put on some new cheap AT tires from a chain store. No vibrations at the time but what a harsh ride! A couple months back I started getting a vibration barely noticeable at 40-45mph but building to a peak around 65-68mph. Thought I had toss a weight so I had the tires balanced at Goodyear. No change and on a whim I bought new tires thinking maybe an internal separation. New Goodyear Trailrunner AT's in 225/75R15's. After installing, still no change in the vibrations, although they ride so much nicer!
So... 20-25 hours later pulling driveshafts, inspecting front carrier, front axle shafts, hubs, brakes, suspension, driveline angles, measuring axle and wheel run-out, engine mounts, and every other thing I can think of. Still the vibration persists.
With images of a gas can & match forming in my head, I decided to take the tires to another shop. They found that all four tires that Goodyear balanced with their "state-of-the-art" Hunter 7700 was out 3/4oz on both sides of each tire. I only just got one quick drive tonight and the vibrations are gone. Lesson learned - don't assume the tire shops always get it right. Jerry B. has said this in other posts and he was right.
So... 20-25 hours later pulling driveshafts, inspecting front carrier, front axle shafts, hubs, brakes, suspension, driveline angles, measuring axle and wheel run-out, engine mounts, and every other thing I can think of. Still the vibration persists.
With images of a gas can & match forming in my head, I decided to take the tires to another shop. They found that all four tires that Goodyear balanced with their "state-of-the-art" Hunter 7700 was out 3/4oz on both sides of each tire. I only just got one quick drive tonight and the vibrations are gone. Lesson learned - don't assume the tire shops always get it right. Jerry B. has said this in other posts and he was right.
OP
Thanks for you insight on the problem. My vibes don't feel like the typical wheel balance vibes. I've had them too as well as DW over the years of TJ ownership, so I know what they feel like. This vibration is a harmonic sin wave type of vibes, and is higher frequency. Also, in an effort to rule out my wheels/tires as the culprit, I swapped wheels/tires with a buddy's TJ and still had the same vibes, no change. Glad you were able to sort out your vibes though.
OP
Hope to work on the jeep Sunday. I have an ambitious list of things to do. Replace leaking radiator with a Mopar unit. Replace front shocks, Change trany mount, change TB, re-re-check CA's, unit bearings and anything else I can think of while I have it in the air. Anything else you guys think I should look at?
Had a bad vibration on the way home from the tire shop in my Dodge truck. When I investigated, I found 6.5 ounces of weight on the wheel (side facing inward). A nice little train of wheel weights running along the rim... Took it to another shop to have the tire rebalanced, where they showed me I had a bent rim. I've never gone back to the first shop.
I had the same problem with a driveline vibe. Mine started around 45 and got worse the faster I went. After 5 months of chasing it I found it. I had put an advance adapters SYE in when I did the lift, new complete rear axle assembly, new rear drive shaft and rebuilt the front Dana 30. Took the sye output shaft out and took it to a machine shop and it was out of true. Got it replaced under warranty and I now have no vibes until I get over 75 which I think is mud tires I put on.
TJ’s are notorious for having a very short rear driveshafts. One reason behind so many driveline vibe postings. Just spit ballig here. Wonder if it would help if you had a super short SYE and a much longer rear driveshaft.
I firmly belive it to be a combination of small things like the possible trans mount and a lemon rear shaft.
OP
After I do these latest rounds of replacing shit, I will replace the rear diff yoke(upgrayed), then take the rear drive shaft out to verify. The SYE output shaft out of round is something I would never have considered, and would be very disappointing if that is the culprit concerning the labor involved.