OP
Not within speeds I'm willing to go. I've had it to 86ish.
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Please help me solve the oscillating vibration crisis by providing some basic info on your Jeep
- Thread starter freedom_in_4low
- Start date
Not within speeds I'm willing to go. I've had it to 86ish.
OP
1995 Jeep YJ
1. Yes, 75-77 MPH and then 78-80 after Dana 44 swap with hubs disconnected
2. Yes, though no notable pulse with rear shaft removed and driving around in FWD.
3. 95 YJ, Sport, 4.0L
4. Dana 30/8.8, 4.88's, TrueTrack rear, Aussie Locker in front - then switched to Dana 44/Dana 44 combo
5. 35 x 12.5 MT/R
6. AX 15
7. NP 231, AA SYE then JB Conversions SS SYE, Adams Driveshaft CV
8. Stock
9. Stock
10. 4" springs, 1/2" shackle lift
11. None noteworthy
Some notes: I spent months trying to figure this out. People - including some of the resident "experts" on this forum, insisted I was an idiot, didn't know how to check or adjust pinion angles properly, and that the I6 engine was so inherently perfectly balanced that it couldn't possibly be the cause of any issue. I was also working closely with James from Adam's Driveshafts. He confirmed the original driveshaft balance was perfect (on his new-at-the-time high speed balancer) with no change in pulse, then he sent me a larger diameter shaft which seemed to reduce the pulse amplitude but didn't notably change the speed at which it occurred. I traced a problem back to my original Advanced Adapters SYE and swapped to a JB SS SYE. The pulse was still there but the frequency changed some and the amplitude was drastically reduced (speed at which pulse started was not changed). I was able to cruise comfortably at 80 MPH without being annoyed. At above ~82 MPH, the pulse would literally shake my inner ears and tickle them, driving me mad!
1998 Jeep TJ
1. Yes, 78-80 MPH
2. Yes
3. 98 TJ, Sport, 4.0L
4. D30HP/Dana 44, 5.13, e-lockers in both
5. 35 x 12.5 MT/R
6. AX 15
7. NP 231, JB Standard SYE, Adams Driveshaft CV
8. Stock and then UCF Ultra High - no change in pulse
9. stock and then Savvy - no change in pulse
10. 3.5" RK Triple Rate + 3/4" spacer
11. Rear upper perch mount relocated to reduce rear spring arch, no change in pulse
With earphones, you can hear to pulse in this video of me cruising at 80:
2006 Jeep LJ
1. Yes, 71-73 MPH
2. Have not checked on the LJ
3. 06 LJ, 4.0L
4. D30HP/Dana 44 (same axles from the 98 TJ above), 5.13 and e-lockers in both
5. 35 x 12.5 MT/R (same tires as TJ)
6. NSG 6-speed
7. NP 231, JB Standard SYE (same t-case as TJ)
8. UCF High
9. Stock then Savvy, no change
10. 3.5" RK w/ 3/4" spacer then 4" Procomp
11. None
One other interesting tidbit: I did note a few times where the pulse would suddenly disappear as load changed. For example, back in AZ, there was a stretch of highway between Phoenix and Mesa (on the Loop 202 for the locals!) that climbs a slow but steady grade (maybe 1% over 4-5 miles). On more than one occasion, in both the TJ and YJ, the pulse completely stops on this stretch! It wasn't every time - but I definitely noticed it a few times and even noticed it with a passenger inside. I didn't notice it on the LJ as I moved to PA by the time she was road ready.
Another interesting tidbit: the pulse changed when towing a trailer (even a lightweight, empty trailer). It would drop the MPH at which the pulse started by ~2-3 MPH with the YJ (I never towed on the TJ to see if that changed the pulse there).
1. Yes, 75-77 MPH and then 78-80 after Dana 44 swap with hubs disconnected
2. Yes, though no notable pulse with rear shaft removed and driving around in FWD.
3. 95 YJ, Sport, 4.0L
4. Dana 30/8.8, 4.88's, TrueTrack rear, Aussie Locker in front - then switched to Dana 44/Dana 44 combo
5. 35 x 12.5 MT/R
6. AX 15
7. NP 231, AA SYE then JB Conversions SS SYE, Adams Driveshaft CV
8. Stock
9. Stock
10. 4" springs, 1/2" shackle lift
11. None noteworthy
Some notes: I spent months trying to figure this out. People - including some of the resident "experts" on this forum, insisted I was an idiot, didn't know how to check or adjust pinion angles properly, and that the I6 engine was so inherently perfectly balanced that it couldn't possibly be the cause of any issue. I was also working closely with James from Adam's Driveshafts. He confirmed the original driveshaft balance was perfect (on his new-at-the-time high speed balancer) with no change in pulse, then he sent me a larger diameter shaft which seemed to reduce the pulse amplitude but didn't notably change the speed at which it occurred. I traced a problem back to my original Advanced Adapters SYE and swapped to a JB SS SYE. The pulse was still there but the frequency changed some and the amplitude was drastically reduced (speed at which pulse started was not changed). I was able to cruise comfortably at 80 MPH without being annoyed. At above ~82 MPH, the pulse would literally shake my inner ears and tickle them, driving me mad!
1998 Jeep TJ
1. Yes, 78-80 MPH
2. Yes
3. 98 TJ, Sport, 4.0L
4. D30HP/Dana 44, 5.13, e-lockers in both
5. 35 x 12.5 MT/R
6. AX 15
7. NP 231, JB Standard SYE, Adams Driveshaft CV
8. Stock and then UCF Ultra High - no change in pulse
9. stock and then Savvy - no change in pulse
10. 3.5" RK Triple Rate + 3/4" spacer
11. Rear upper perch mount relocated to reduce rear spring arch, no change in pulse
With earphones, you can hear to pulse in this video of me cruising at 80:
2006 Jeep LJ
1. Yes, 71-73 MPH
2. Have not checked on the LJ
3. 06 LJ, 4.0L
4. D30HP/Dana 44 (same axles from the 98 TJ above), 5.13 and e-lockers in both
5. 35 x 12.5 MT/R (same tires as TJ)
6. NSG 6-speed
7. NP 231, JB Standard SYE (same t-case as TJ)
8. UCF High
9. Stock then Savvy, no change
10. 3.5" RK w/ 3/4" spacer then 4" Procomp
11. None
One other interesting tidbit: I did note a few times where the pulse would suddenly disappear as load changed. For example, back in AZ, there was a stretch of highway between Phoenix and Mesa (on the Loop 202 for the locals!) that climbs a slow but steady grade (maybe 1% over 4-5 miles). On more than one occasion, in both the TJ and YJ, the pulse completely stops on this stretch! It wasn't every time - but I definitely noticed it a few times and even noticed it with a passenger inside. I didn't notice it on the LJ as I moved to PA by the time she was road ready.
Another interesting tidbit: the pulse changed when towing a trailer (even a lightweight, empty trailer). It would drop the MPH at which the pulse started by ~2-3 MPH with the YJ (I never towed on the TJ to see if that changed the pulse there).
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OP
Don't know how much troubleshooting you've done but you have an odd duck. You're the only 32RH, and your onset is less than 2200rpm,several hundred lower than anyone else. Have your u-joints, pinion angles, and driveshaft balance been checked and ruled out?
I honestly haven't taken the time to trouble shoot this much. Eventually I will take the time to dive into this more but I've gotten used to it and avoid the problematic speed range. If I accelerate through it I don't have any issues. Sustained speed in this range is what gets it.
OP
Ah. The fact that it goes away as speed increases points to a balance issue. Either the shaft needs balanced, maybe a u joint or centering ball is worn and has some slop.
I will have to climb under there and look at the U joints. I wouldn't be surprised if it's a balance issue either, I need to pull the front and rear drive shafts one at a time and see if either one makes a difference. I appreciate the input!
Rear outer pinion bearing is starting to make noise again. The harmonic is not being kind to it.
LBCLJR
New Member
My first post here but since I spent a lot of time and money on this issue last year I figured this would be a good place to start.
1. Yes, around 60. After the 5.13 regear, if it was vibrating with the 4.11s I never noticed.
2. No
3. 2005 LJ Rubicon
4. Rubicon 44s 5.13s stock carriers
5. 255/85 R16 (33X10.50)
6. Auto
7. 241
8. Stock
9. Stock
10. 3.5" short arm
11. No
Before I did the hubs I had the front driveshaft rebuilt and balanced, tires road force balanced, the pinon angles adjusted. With the front DS out it was smooth. I actually emailed Blaine. He was cool and called me and gave me some advice on other things to try. I also talked to a few local shops that said they had experience curing vibes and were confident they could fix it. But I started to feel like it was good money after bad. Aside from the vibes I was really happy with how it drove.
I ultimately decided to go with the hubs. I did the 5X4.5 kit because the 5x5.5 kit was on major backorder at the time and I didn't really want to wait. After the hubs it's smooth as fast as I can drive it. I've surprised myself at 80 on the freeway and feels rock steady.
1. Yes, around 60. After the 5.13 regear, if it was vibrating with the 4.11s I never noticed.
2. No
3. 2005 LJ Rubicon
4. Rubicon 44s 5.13s stock carriers
5. 255/85 R16 (33X10.50)
6. Auto
7. 241
8. Stock
9. Stock
10. 3.5" short arm
11. No
Before I did the hubs I had the front driveshaft rebuilt and balanced, tires road force balanced, the pinon angles adjusted. With the front DS out it was smooth. I actually emailed Blaine. He was cool and called me and gave me some advice on other things to try. I also talked to a few local shops that said they had experience curing vibes and were confident they could fix it. But I started to feel like it was good money after bad. Aside from the vibes I was really happy with how it drove.
I ultimately decided to go with the hubs. I did the 5X4.5 kit because the 5x5.5 kit was on major backorder at the time and I didn't really want to wait. After the hubs it's smooth as fast as I can drive it. I've surprised myself at 80 on the freeway and feels rock steady.
It SUCKS that you are still dealing with this. I wish there were something we could do to get you driving vibe free.
We should take up a go fund me and buy the dude a new rear axle!
I figured why not give it a shot.
1. Do you have the oscillating vibration issue and at what speed does it start? Yes, it begins to be noticeable at 70 and very incrementally increases in loudness up to 85. Overall I am happy with the level of vibration and consider it livable. A non-mechanically minded person might not notice it.
2. does it persist even with the front driveshaft removed? I have not removed the front driveshaft yet.
3. Model year and TJ or LJ: 2005 LJR
4. Axles and Gear ratio (and if you have a Rubicon, did you keep thick cut gears or did you get a 3.92+ carrier and go to standard gears?) I have dana 44 front and rear with factory gears 4.10s.
5. Tire size 30/9.5/16
6. transmission: NSG-370
7. transfer case, and if 231, is it SYE'd: A stock 241.
8. stock or aftermarket transfer case skid, and if aftermarket, which skid (please include brand, tuck height, and material). Stock skids.
9. stock or aftermarket gas tank skid, and if aftermarket, which skid? Stock skids.
10. suspension lift height, if any: 2.5 inch OME lift
11. any other mods that might change the way the frame is constrained, such as a stretch, midarm, rear frame raise, crossmember deletions, spring perch relocations, shock outboard, etc. No major or permanent modifications. 2.5 inch lift is a simple lift just springs shocks bumpstops jks sway bar links and rear track bar bracket, stock front track bar tie rod etc.
1. Do you have the oscillating vibration issue and at what speed does it start? Yes, it begins to be noticeable at 70 and very incrementally increases in loudness up to 85. Overall I am happy with the level of vibration and consider it livable. A non-mechanically minded person might not notice it.
2. does it persist even with the front driveshaft removed? I have not removed the front driveshaft yet.
3. Model year and TJ or LJ: 2005 LJR
4. Axles and Gear ratio (and if you have a Rubicon, did you keep thick cut gears or did you get a 3.92+ carrier and go to standard gears?) I have dana 44 front and rear with factory gears 4.10s.
5. Tire size 30/9.5/16
6. transmission: NSG-370
7. transfer case, and if 231, is it SYE'd: A stock 241.
8. stock or aftermarket transfer case skid, and if aftermarket, which skid (please include brand, tuck height, and material). Stock skids.
9. stock or aftermarket gas tank skid, and if aftermarket, which skid? Stock skids.
10. suspension lift height, if any: 2.5 inch OME lift
11. any other mods that might change the way the frame is constrained, such as a stretch, midarm, rear frame raise, crossmember deletions, spring perch relocations, shock outboard, etc. No major or permanent modifications. 2.5 inch lift is a simple lift just springs shocks bumpstops jks sway bar links and rear track bar bracket, stock front track bar tie rod etc.
OP
I'm not sure whether that TJ needs an axle or an exorcist.
*new TJ
I'm pretty curious if my transmission swap ends up moving the vibration out of range, or at least solves what I have with rear shaft only and finally opens the way to hubs being the full solution. From numbers I'm seeing on the internet the AX15 may weigh about 20 pounds more than the nsg370.
I'm really tempting fate with my impending 42RLE swap...
OP
Just go ahead and get a rubicrawler with it and save yourself the trouble.
It would be interesting if it can either makes the vibes disappear or get you to a stage where you can out hubs in and be done with this. The weight difference is nothing, don't think that will contribute much. It will be the entire system and how it responds.
Alteast you are doing it in steps .. regear first and then the trans so you have some sense of what is happening.
If you guys gonna perform exorcism, give me head up, i will bring my bothers 08 JK. I swear there is a poltergeist living in that Jeep, there is simply no natural explanation behind shenanigans going on in that thing.