Harmonic vibration after install a new gears? 
Jeep gladiator M220/M210 axles.
Jeep is brand new with only 800 miles and completely stock, started with 3.73 gears changed to 4.88. (Yukons). 31.5” tires stock.
I used to shop with one of the best reputations in the state, has done hundreds of...
My JL had the wine, and my brand new gladiator has a very, very, very slight whine from new, also I rent a lot of vehicles in whenever have a chance to rent a jeep. Several tend to have a whine as well. On my JL I put over 30,000 miles with whining, never had any issues, I think these ones just...
JScan, used it on my JL and now my JT. Everything including the license is under $100 total for initial setup. Also you don’t need to worry about undoing anything when you take it to the dealer.
I sold my 3.8 JK about 7 years ago and miss it everyday. Re-geared to 5.13 and loved that Jeep, I am talking about picking up another one 'just to have" next year lol.
Out of those 2 I would go with the Dynatrac. However I would go Teraflex over either. Price is inline with the Synergy but a better built balljoint in my opinion.
These are the tires I am buying, same width and size. I wanted the AT3/w however those are backordered and Falken can't provide a date when they will be available. Discount showed me these and I was sold. Plus they are a C rated tire which I prefer.
Those wheel spacers had nothing to do with the failure, 1000's of people have run spacers here in Utah and Moab for decades, the majority never have an issue with them. Those were Synergy spacers, one of the top 3 spacers made in my opinion.