Put the gear selector in 3 instead of drive

 

you could look into using airsoft pellets in the tires instead of weights!!!! I want to do this but just need to find a friend that has a tire shop so I can test it...i hear they are more accurate and adjust to temperature change and foreign objects(mud and snow on the tires).

I also have a possible Harmonic issue. Mine is a bit different but mine has a whine or squeal noise or even a whistle noise...I was told it could be the steering pump/alternator/Harmonic Balancer/Clutch fan/AC Clutch/water pump/Idle pulley. I have replaced the CL Fan/water pump and still it is their...

Going on two weeks now, I could hear a knocking noise under the car after I replaced the catalytic to rear. I noticed that I had a rear seal leak (I did a oil change/filter and Tranny oil/filter) and cleaned the pans and housings very well and that is how I noticed it. I also noticed the streaks of oil lines coming from the front of the oil pan area where the harmonic balancer is located. long story short....I believe that the HB went bad and is hitting metal to metal and causing the sounds. to the eye you can't tell that it is wobbling but I believe it caused the front seal to leak where it is located. I believe this caused stress to my flexplate and it cracked(the knocking noise)(bolts were kinda tight and no oval grooves. I torqued them and locktight, but think I have the ring crack). teeth on the flexplate were chipped and worn in certain areas, which leads me to believe that the starter was the culprit the whole time...smh...the previous owner replaced the start and I think it was installed incorrectly because the start bolts were tight as well, oh and my TTC is throwing up the P0740 code( I replaced and cleaned the NSS/Cleaned the Throttle body/air filter/cleaned IAC sensor/replaced TBS)....ANYONE PLEASE CHIME IN, if you think I am wrong or off on some my diagnosis!!!!

I also still have an outrageous shutter and vibrations. first I have a 4.5inch lift on 35x12.50x15 with the 1inch TC drop, which bother me greatly because I swapped it off my other jeep before I sold it and had no issues (other jeep was a 4x2 if that matters). I have the grinding noise and groan under my feet too after I let off the gas and the strong vibrations when I come from a stop and accelerate. I also get strong vibrations on my dash, do you? I have a rough or strong idle while stopped in gear(Drive and Reverse), do you?

I was told the causes are possibly one of these:
1. bad driveline angles (install SYE) but what all goes with that besides the actual kit? (ordering)
2. bad motor Mounts (ordering)
3. bad tranny Mount (ordering)
4. bad tranny fluids(wrong fluid for vehicle) or dirty filter (done but another change to clean old fluid)
5. bad U-joints throughout the drive line (ordering)
6. bad wheel alignment (fixed)
7. unbalanced tires (new and were done)
8. gears are not adequate enough for tires (will be installing 4.88)
9. bad tie rods
10 bad pitman

there are more but can't remember them all. This is my daily drive now and want it to be my trail and vaca vehicle since my Camaro SS is not ideal for either... I don't have to replace some of these things but she has 224k and I want her to run as clean as possible. XJ's are a money pit but are so fun to have at the same time. she has more issues, but to be honest, if I didn't do all of this, she would still run for a long while.

 

The reason I asked about the angles is I just did a RC 3.5" lift with lower arms on my JGC and used the supplied transfercase drop but had exactly what you are having. I ordered a set of adjustable upper arms for the rear and adjusted the rear pinion angle and now noise and vibration are gone. Just a couple degrees can make all the difference.

Max

 

It's a possibility, that's why I'm going to get an SYE to rule that out, or cure it, who knows? The thing is, this was happening when I was stock, just less noticeable. I don't think it's getting any worse, so I'll just ride it out until the SYE's installed, and go from there.

@Santos, it seems like you might have multiple issues that may not all relate to each other. If you have the cash, install an SYE. Just makes things easier. Honestly, I wish I would have waited till I had an SYE before I installed my lift. I was just too antsy to get her up in the air.

 

Even with the slip yoke elim you may still have to rotate the diff upwards.

Max

 

Right. I plan on shimming the axle to get the angles correct.

 

So I know this is an older thread of mine, but I wanted to post my solution to this problem. I installed my SYE this past weekend, and although I haven't shimmed my axle (doing it this weekend), All the vibrations and harmonic noises I was hearing/feeling are 95% gone. All I have are some VERY minor vibes at low speed, which I'm sure will be eliminated when I shim the axle.

Happy trails!

 

Weird, you said some/most of the problem was there when stock.

 

True. I wonder if the stock driveshaft was bent or unbalanced. I ended up getting a FSM and it said vibrations and noises at certain speed are because of ujoints or incorrect DS angles. Ujoints didn't help, but a new DS and SYE sure did.

 

Any chance it's the exhaust? ok I see now the responses on page 2. Sorry.