Where can I find one of those?? Like the look. And does seem to me better than stock.
Arizona Rock Crawler
- Thread starter starkey480
- Start date
Well, I took today to help my dad dial in his TJ a little bit. He recently put on a Barnes skid plate that gives a 1” tuck, regeared from 3.73 to 5.13 with a grizzly locker in the rear. He’s still on 33s but wants 35s soon. I went over to help him drive the Jeep around to get some break in miles and man did it have a bunch of problems. It had every vibe in the book! Idle vibe, acceleration vibe, high speed vibe, high speed harmonic. And bad! But at the end of the day we got it down to just a small front driveshaft vibe @65 mph.
First step was to isolate the vibes. Removed front driveshaft to just work on the rear.
I noticed there were 2 bolts from the Barnes mounting plate pressing up into the tranny mount. No good! ground down those bolts and boom idle roughness gone.
Next noticed his pinion slope was .7* higher than the driveshaft slope. No good! Dropped that pinion to about .5* lower than the driveshaft. Much smoother still needed work.
Replaced the ujoint in the rear driveshaft at the pinion and wala! No more vibes all the way up to 70mph.
Put the front driveshaft back on and still a vibe at 65. Checked pinion and pinion is 1* higher than the shaft which should be the happiest geometry for that ujoint. We can’t go any lower even if we wanted to because rubicon express makes shitty control arms and they won’t go short enough. We also tried my driveshaft and still vibes.
And that’s where we left off! Not sure the next steps but a hub kit may be in his future as well. Maybe 35s will decrease the high speed vibes enough though
not sure what we will try next.
First step was to isolate the vibes. Removed front driveshaft to just work on the rear.
I noticed there were 2 bolts from the Barnes mounting plate pressing up into the tranny mount. No good! ground down those bolts and boom idle roughness gone.
Next noticed his pinion slope was .7* higher than the driveshaft slope. No good! Dropped that pinion to about .5* lower than the driveshaft. Much smoother still needed work.
Replaced the ujoint in the rear driveshaft at the pinion and wala! No more vibes all the way up to 70mph.
Put the front driveshaft back on and still a vibe at 65. Checked pinion and pinion is 1* higher than the shaft which should be the happiest geometry for that ujoint. We can’t go any lower even if we wanted to because rubicon express makes shitty control arms and they won’t go short enough. We also tried my driveshaft and still vibes.
And that’s where we left off! Not sure the next steps but a hub kit may be in his future as well. Maybe 35s will decrease the high speed vibes enough though
not sure what we will try next.
Well, I took today to help my dad dial in his TJ a little bit. He recently put on a Barnes skid plate that gives a 1” tuck, regeared from 3.73 to 5.13 with a grizzly locker in the rear. He’s still on 33s but wants 35s soon. I went over to help him drive the Jeep around to get some break in miles and man did it have a bunch of problems. It had every vibe in the book! Idle vibe, acceleration vibe, high speed vibe, high speed harmonic. And bad! But at the end of the day we got it down to just a small front driveshaft vibe @65 mph.
First step was to isolate the vibes. Removed front driveshaft to just work on the rear.
I noticed there were 2 bolts from the Barnes mounting plate pressing up into the tranny mount. No good! ground down those bolts and boom idle roughness gone.
Next noticed his pinion slope was .7* higher than the driveshaft slope. No good! Dropped that pinion to about .5* lower than the driveshaft. Much smoother still needed work.
Replaced the ujoint in the rear driveshaft at the pinion and wala! No more vibes all the way up to 70mph.
Put the front driveshaft back on and still a vibe at 65. Checked pinion and pinion is 1* higher than the shaft which should be the happiest geometry for that ujoint. We can’t go any lower even if we wanted to because rubicon express makes shitty control arms and they won’t go short enough. We also tried my driveshaft and still vibes.
And that’s where we left off! Not sure the next steps but a hub kit may be in his future as well. Maybe 35s will decrease the high speed vibes enough though
Did you keep the same driveshafts as before the lift? The increase in RPM from the gears can make every little issue in the driveshaft show up. I had a problem with the front slip joint being loose and causing bad vibes. If you push up and down on the slip there should be no movement.
His front driveshaft is the same and he’s had the lift for a while. We tried his driveshaft as well as a driveshaft that was completely rebuilt a year ago so chances are it isn’t the slip. He does have some play in the yoke on the tcase. In and out play. It’s more than mine has and mine has some as well. Is there supposed to be any in and out play on the tcase yoke?
Yes, there will be a small amount of in/out play in the output yoke. Zero play on the diff. 35's will slow the drive shaft RPM down a bit, which may help with the higher speed vibes.
Cool everything’s good there then. So my dads is the same exact year as mine (99’) and we were both able to get the rear shaft completely vibe free after regear and it’s just a front vibe on both our rigs. There has to be something common that causes this on so many rigs post regear! How has no one found the answer? I was talking to @mrblaine the other day and he was saying we as a Jeep community should be better at figuring this out. But, the unfortunate reality is it’s either spend countless hours and dollars of your own time, pay countless hours of someone else’s time to diagnose it, or take the easy way out and hub kit. He said he doesn’t like the hub kit answer but sometimes reality makes it the best answer.
You are one of the few folks that has ever been able to paraphrase my position exactly.
I appreciated you taking time to help me so I listened carefully. Thanks again!
I may have forgotten to mention that the bearings on the spindle are only speed rated to 73 mph.
harbor freight 20 ton press works perfect! Made U joints such an easy job
Mr. Pink
TJ Enthusiast
I see the problem. You can't do it that way. You have to have 2 pieces of steel bar stock that are 12" long, 3" wide and 1" thick. They stand up and the flange for the studs rests on top of them. They will hit flat on two studs on one side and just miss the stud being pressed in on the other side.
The only other way to do it like you have it there is to drill holes in the press plates so the studs will go into them and the flange is still supported.
That helps a ton thanks!
For those wondering I made an embarrassing mistake and cracked one of the rotors in the press as well as ruining the bearing hub. You live and you learn. Blaine is very graciously sending some spares that he has so that I can “get that piece of shit back on the road again” - Blaine
Well one good thing happened yesterday, I let my dad try my new Tom Woods Driveshaft and he says it almost entirely got rid of his vibes up to 75. Which means when he goes from 33s to 35s they will be at an irrelevant speed. Looks like he will be buying my driveshaft from me!
You left out the very best part.That helps a ton thanks!
For those wondering I made an embarrassing mistake and cracked one of the rotors in the press as well as ruining the bearing hub. You live and you learn. Blaine is very graciously sending some spares that he has so that I can “get that piece of shit back on the road again” - Blaine
Hey, Chris just moved here and he's my neighbor now.
Oh, you're the group of homosexuals he was all excited about.
No, no, that's not us, we must be one house over.
Hey, I wasn't judging, just putting 2 and 2 together.
Update on the hub kit install:
Yukon sent the wrong wheel studs. They are way too fat for the holes in the flange. The knurl diameter is .608 and the hole diameter they are being pressed into is .583. That’s a .025 difference and the tolerance is supposed to be .005-.01. Blaine said he’s had to change the studs or ream the holes bigger the last 5 installs he’s done. On top of that the studs don’t even have the shoulder they are supposed to have for the rotor to press into. I don’t get how Yukon fucks this up so bad. Will call Randy’s on Monday or just get new studs myself so I can get this done already.
Moral of the story is if you install a hub kit CHECK YOUR STUD DIAMETER
Yukon sent the wrong wheel studs. They are way too fat for the holes in the flange. The knurl diameter is .608 and the hole diameter they are being pressed into is .583. That’s a .025 difference and the tolerance is supposed to be .005-.01. Blaine said he’s had to change the studs or ream the holes bigger the last 5 installs he’s done. On top of that the studs don’t even have the shoulder they are supposed to have for the rotor to press into. I don’t get how Yukon fucks this up so bad. Will call Randy’s on Monday or just get new studs myself so I can get this done already.
Moral of the story is if you install a hub kit CHECK YOUR STUD DIAMETER
Wait until the rotors get there. Then you can check the stud holes and we'll see what it takes then.
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