Re-geared, now I have a vibration above 50 mph

curious why a 5x5.5 kit over 5x4.5?

Did you run 5.5 in the front and 4.5 in the rear?

My main reason was because I wanted to maintain the factory width. The 4.5 adds width to the front axel. I don’t believe there is any strength difference between the two, the rear I already had axels that were drilled for both patterns so it was as simple as drilling out the rear rotors for the new pattern and swapping the studs around.
 
No, I am saying that the 5x4.5 kit makes the front track 1.5" wider (3/4" per side). The 5x5.5 kit does not.
IF that is really the case, then I have to do a 5.5 myself which means I will wait till tire time because I just bought 31's then a few months later 33's and a few months later now. I just can't buy another set of wheels and tires yet haha.
 
IF that is really the case, then I have to do a 5.5 myself which means I will wait till tire time because I just bought 31's then a few months later 33's and a few months later now. I just can't buy another set of wheels and tires yet haha.


It’s not IF it makes it wider it DOES make it wider. The spindle adds about 1/2” to the width, and then they reuse the stock rotor and add the outer portion of the hub to the rotor that is 1/4”. The 5x5.5 kit uses a CJ rotor and they shorten the spindle up. I measured everything and it was actually 1/8” narrower per side than the stock set up so 1/4” narrower overall
 
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I would suggest having a reputable shop check out the installation of the gears and check the whole drive line to get to the root of the problem as well as having your tires balanced and aligned. It could be a number of things.
 
My vibe was related to the front shaft. I am guessing it did not like turning faster, and created a harmonic pulsing vibe that started in the front and felt like it moved to the back. It would show up around 62 mph and reduce at around 70 or so. I tried removing the front shaft and it would go away and I could run 80. Installed the front and removed the rear and still had it. Installed a new Tom Wood front and still had it, adjusted the pinion angle in half degree points up and down and would still have it. Had new tires and front end, also made sure everything was tight including the lugs and wheels and still had it. The hub kit was mentioned and that is the only thing that solved the issue.
 
I also have the Yukon 5x5.5 manual hub conversion. I chose it over the Yukon 5x4.5 manual hub conversion kit for three reasons: 1) Bigger and stronger than the Ford style 5x4.5 hubs (although @mrblaine observed that in practice hub strength of the 5x4.5 kit isn't much of an issue); 2) I didn't like the idea of the 5x4.5 kit widening the front track 1.5" with no good way to match the rear track (although @mrblaine informed me that he actually prefers to set up jeeps that way rather than equal track front and rear); but most importantly (3) I was able to get a killer price on the 5x5.5 kit from Amazon that was $650 off retail and $400 less than the 5x4.5 kit. In the end I had to purchase $525 worth of new wheels with the 5x5.5 lug pattern, offset by the $400 I received for my old wheels, and it cost $75 to remount and re-balance my existing tires, so I really only saved $200 over the 5x4.5 kit.

Do I regret my choice to go with the 5x5.5 kit rather than the 5x4.5 kit? Absolutely not.

View attachment 82180
I'd like to see a picture of that jeep those wheels look terrific.
 
It’s not IF it makes it wider it DOES make it wider. The spindle adds about 1/2” to the width, and then they reuse the stock rotor and add the outer portion of the hub to the rotor that is 1/4”. The 5x5.5 kit uses a CJ rotor and they shorten the spindle up. I measured everything and it was actually 1/8” narrower per side than the stock set up so 1/4” narrower overall
That seems like it is better with my narrow 8.8 rear.
 
2) I didn't like the idea of the 5x4.5 kit widening the front track 1.5" with no good way to match the rear track (although @mrblaine informed me that he actually prefers to set up jeeps that way rather than equal track front and rear);

Not to derail the thread, and my apologies for any ignorance, but I am about to build a rear Dana 44 from a JK, if what you say is correct, I can keep my TJ Dana 30 and install the 5x4.5 hub kit and kind of close that gap between the front and rear track width.
In theory (aka, my brain), with the 5x4.5 kit, I'll have a 62" TJ front & 65" rear track, and this is preferred? Or should I add another 1" or so to close that gap with a spacer or??? Most likely a @mrblaine question.

I was rebuilding my front DS, but ended up buying an Adams DS. I have kind of enjoyed running no front DS this past week, locking hubs would be a much cheaper decision that finding a matching front JK Dana 44 to swap.
 
It’s not IF it makes it wider it DOES make it wider. The spindle adds about 1/2” to the width, and then they reuse the stock rotor and add the outer portion of the hub to the rotor that is 1/4”. The 5x5.5 kit uses a CJ rotor and they shorten the spindle up. I measured everything and it was actually 1/8” narrower per side than the stock set up so 1/4” narrower overall
The spindle adds nothing to the width or takes away nothing from either. It is just the carrier for the bearing hub in both kits.
Both kits have behind the rotor flange mounting styles.
Both rotors have very close to the same thickness at the mounting surface in the rotor hat.
The extra width in the smaller conversion comes from keeping the stock rotor and adding the flange from the bearing hub to it and then adding the thickness of the flange on the locking hub to that.

The spindle just has the appropriate spacing between the bearings to make it all happen.
 
Took the rear drive shaft off today and went for a drive. Vibes are virtually gone. Just a slight vibe at 75, but nowhere near as bad. So, I checked torque on both yokes and will put the rear ds back on and double check pinion angles. I've been there so many times I can't believe it's the pinion angle causing the vibes.
 
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Man keep is posted , love to see this resolved.
 
If the vibe is still slightly there, angle the rear down by half a degree or slightly more.

That's the other part of my experiment. Fuel light is on, back seat out, pinion is sitting 2.2* lower than the ds. Rear ds is back in. Going to fill up the tank and repeat. I want to note the pinion angle change after a fuel tank of fuel.
 
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Took the rear drive shaft off today and went for a drive. Vibes are virtually gone. Just a slight vibe at 75, but nowhere near as bad. So, I checked torque on both yokes and will put the rear ds back on and double check pinion angles. I've been there so many times I can't believe it's the pinion angle causing the vibes.

Any other recent changes at all other than the tires? If it's just pinion angles then this saga can come to an end quickly. Keep us posted.
 
Any other recent changes at all other than the tires? If it's just pinion angles then this saga can come to an end quickly. Keep us posted.

No other recent changes since new tires, other than removing the rear seat, which, by the way, weighs 65lbs and is awkward as hell to remove.
 
I'm having some issue making driveshafts last. They keep making a rumbling sound coming from the centering ball. The rear is doing it again 500 miles after a rebuild and the front started doing it after 6000 miles. Primarily 0-35mph, I need to keep them greased every 500 miles to keep them quiet above 35mph. I scheduled a Roadforce tire rebalance at the local Ford dealer to make sure that's not causing some of the issues.

I can feel it in the steering wheel and gas peddle.
 
I was coming here for someone to make my day, someone who recently had an anniversary. Now I'm disappointed.