Apologies for another vibration question

[Flivver250]

My 03' Sport has had vibrations at 60+ MPH. I am certain I had multiple issues, all contributing to vibrations in their own way, and those I have addressed. I have installed an Advanced Adapeter SYE, Tom Woods drive shaft, all new U-joints everywhere, differential bearings, gears, seals, upper and lower adjustable control arms in the rear, the TC case is dropped about an inch, cleaned up the flywheel (will order a new clutch and flywheel at some point), new wheels and tires all new wheel bearings except for the right right. New brakes and more. Tom Woods sent me a new yoke for the SYE, that helped as well, but there was still vibes. My tranny was as sloppy as Courtney Love so I just replaced it with a low mileage junkyard tranny. The replacement tranny is 100% better than the old one. Shifts tighter operates smoother and quiter, happy with that. Still a noticeable vibe above 60MPH. My rear drive shaft is almost perfectly aligned between differential and transfer case. What are the chances the transfer case is the culprit? Another issue I have noticed, the u-joint stops on the input yoke on the rear differential is a little bit wider that the u-joint so you have to take care positioning the drive shaft in the center with a slight gap on either end of the caps. The caps fit tightly, just have end play. I willreplace the yoke? Replace thje transfer case as well?

 

[TJ2]

Very interested to read this post.
My other TJ has exactly the same, very slight vibe bet. 50 - 60 (all parts OEM) I hope it's not major.

 

[S.McArthur]

I've been working on my drive line issue...again, I though I had it fixed with the thrust angle, but nope, I just smoothed it out.Oh, by the way, make sure your axles are square (Thrust Angle).
I have a spreadsheet that is supposed to narrow down the frequency and give an idea where the vib is coming from. I have not field tested it, but I'm working on it. If my half ass free vibration scanning app is correct, my tires are the culprit. Again, this is only based on some research and math.

What is you Tire Size (in metric please, I can convert if in ") and your gearing.

 

[dbbd1]

My tranny was as sloppy as Courtney Love ?

Wait! Courtney Love is a trans???



Back to your question though...
Maybe have your tires re-balanced. For now, you could swap them around, side-to-side/front-to-rear kind of thing. See what happens with the vibe.



Courtney Love? Wow, who knew?

 

[Flivver250]

I just bought a new rear yoke and will replace it tomorrow. I will update the results.

 

[Goatman]

Are you running big mud terrain tires? The tread could cause a vibe all it's own.

 

[Flivver250]

Brand new rims with new Cooper AT3 tires. They are fairly tame. Rebalanced three times.

 

[bobthetj03]

What is your front pinion to drive shaft relationship like? Have you tried removing the front or rear shaft to isolate?

 

[AndyG]

Definitely watch that yoke ...that may solve it .

 

[Flivver250]

Much less vibration with rear DS removed. Next few hours I will replace rear yoke and see how it shakes out, or not. I have been steadily improving the ride, each mechanical attack has been a gain. One of the problem might be, no beer is ever consumed during the repairs and maintenance due to the nature of my location. It is quite possible that the intentional omission of finely crafted hops and barley causes an imbalance in my Jeep's chi. Maybe my Jeep has the DTs?

 

[Flivver250]

Update: I just replaced the rear differential yoke with a brand new one. Total success. Radical reduction in driveline vibration. Due to traffic density I only tested it to 100KPH. All was well. I may still have to tweak tire balance, but I now have the best ride since I bought the sled. Lesson learned: The yokes may look innocent, but those evil bastards can be the culprit.