Nashville TJ's Build - Continued

[NashvilleTJ]

A little bit of maintenance / unexpected upgrade today. My son Ben is a manager at a local Discount Tire, and I buy all of my tires from him - including the meats for the Jeep.

He was over for a visit this week and while hanging in the shop he noticed this:

And this...

"How long have they been like that, Dad?"

"I don't know, since before Moab last year because I remember putting some vulcanizing tire glue on the one with the flap."

"You know your road hazard coverage will cover that, right?"



I have really good kids.

So Ben ordered me two replacements, and I picked them up today.

 

[Wildman]

Awesome kids...
New sneakers are always fun.

 

[NashvilleTJ]

So I spent a little time today mounting the new meats. Pulling the bead lock rings is pretty easy...

Just a few minutes and they are off:

Breaking the back bead - not so much. A long time ago I built a bead breaker which bolts to the floor:

It works - but it is a workout.

And after a bit of sweat and some choice words:

 

[NashvilleTJ]

If you have wheeled with me, you know I'm not easy on the rig (Ryan just recently said my rings make it look like I drive by braille). I noticed a pretty good ding and a decent bend on one of the rings.

A little time at the press took care of that.

 

[Wildman]

If you have wheeled with me, you know I'm not easy on the rig (Ryan just recently said my rings make it look like I drive by braille). I noticed a pretty good ding and a decent bend on one of the rings.

View attachment 412025

A little time at the press took care of that.

View attachment 412030

Well since I've got your old rims I'm inclined to agree with Ryan to a point...

 

[NashvilleTJ]

Then after a little soapy water...

...and some quality time doing 4 or 5 rotations with the inch pound torque wrench..

Good as new!

Just a few weeks ago I threw the spare on the rig for the first time - it's the one on the driver's side front and explains why it is so pristine - so now I have 3 brand new tires on the ground - and one with a couple thousand miles on it. Here's hoping for another road hazard...

Next week I'll take the rig into Ben's shop and have all five wheels balanced. They always do a very good job.

 

[NashvilleTJ]

I’ve been wondering why everyone gives a single number for caster, like ~7* or ~5*. Aren’t the C’s clocked by 0.5*, so that the caster on one side of the axle is 0.5* more or less than the other side? Mine is 6.2* and 6.7*. Just curious.

I don't recall ever checking both sides, as you can't do anything about that. I'm running a custom Pro-Rock 60 in the front, and I don't know if they are clocked differently or not. I always measure on the driver's side, and I got to 7 by doing a lot of testing. Since I run lockouts, I can set the castor so I get the best steering, and don't have to worry much about vibes. That said, even when locked I don't get vibes up front.

 

[reddvltj]

Than after a little soapy water...

View attachment 412034

...and some quality time doing 4 or 5 rotations with the inch pound torque wrench..

View attachment 412035

Good as new!

View attachment 412036

Just a few weeks ago I threw the spare on the rig for the first time - it's the one on the driver's side front and explains why it is so pristine - so now I have 3 brand new tires on the ground - and one with a couple thousand miles on it. Here is hoping for another road hazzard...

How are you liking the traction of the RAZRs? I know they're pretty soft, I have a set of them (285/65 R20 E, 34x11) on my '06 Dodge and with barely over 10k on them they're down to about 50%

 

[JMT]

I don't recall ever checking both sides, as you can't do anything about that. I'm running a custom Pro-Rock 60 in the front, and I don't know if they are clocked differently or not. I always measure on the driver's side, and I got to 7 by doing a lot of testing. Since I run lockouts, I can set the castor so I get the best steering, and don't have to worry much about vibes. That said, even when locked I don't get vibes up front.

If you set up your CA’s wrong the caster will not be 0.5* off because you’re forcing one side of the axle into an unhappy position. That last bolt in the upper CA is put in with the arm adjusted to the length it’s “supposed” to be. Overall just wanting to understand more of this. Thanks.

 

[NashvilleTJ]

How are you liking the traction of the RAZRs? I know they're pretty soft, I have a set of them (285/65 R20 E, 34x11) on my '06 Dodge and with barely over 10k on them they're down to about 50%

Traction is good for a non-sticky, and they are decent on the street. Better in the mud than my old Krawlers. But, they are soft. I only have a few thousand miles on them, and they’ve lost a good bit of tread already (granted, I’m usually smoking them in the rocks). The sidewalls are nowhere near as tough as my old Krawlers - as you can see by the pics above.

Overall, I think I would do something more agressive next time.

 

[reddvltj]

Traction is good for a non-sticky, and they are decent on the street. Better in the mud than my old Krawlers. But, they are soft. I only have a few thousand miles on them, and they’ve lost a good bit of tread already (granted, I’m usually smoking them in the rocks). The sidewalls are nowhere near as tough as my old Krawlers - as you can see by the pics above.

Overall, I think I would do something more agressive next time.

Judging by the look of your bead lock rings I'd say the sidewalls held up pretty good... other than the flap...

 

[NashvilleTJ]

If you set up your CA’s wrong the caster will not be 0.5* off because you’re forcing one side of the axle into an unhappy position. That last bolt in the upper CA is put in with the arm adjusted to the length it’s “supposed” to be. Overall just wanting to understand more of this. Thanks.

If the inner C’s are set up .5 degrees off, there is nothing you can do to your control arms to alter that. Think about what would have to occur for that to happen - you would need to twist your solid axle by a half a degree from one side to the other. Someone correct me if I am wrong, but I don’t think that will happen no matter what you do with the control arms.

Also, if you set up your control arms properly, they are not in bind at ride height.

 

[Woodrow]

I’ve been wondering why everyone gives a single number for caster, like ~7* or ~5*. Aren’t the C’s clocked by 0.5*, so that the caster on one side of the axle is 0.5* more or less than the other side? Mine is 6.2* and 6.7*. Just curious.

And does anyone know why that is the case? Does it help with straight tracking on a crowned road? Does it have to do with asymmetry in the steering set up? Something else?

 

[reddvltj]

And does anyone know why that is the case? Does it help with straight tracking on a crowned road? Does it have to do with asymmetry in the steering set up? Something else?

Correct, typically manufacturers set slightly higher caster on the passenger side to correct for road crown.

Here's the factory alignment specs for TJ/TJU (LJ)
(notice the max difference for caster)

https://www.wanderingtrail.com/Mech...djust_Repair/Steering_Alignment/Alignment.htm

 

[JMT]

If the inner C’s are set up .5 degrees off, there is nothing you can do to your control arms to alter that. Think about what would have to occur for that to happen - you would need to twist your solid axle by a half a degree from one side to the other. Someone correct me if I am wrong, but I don’t think that will happen no matter what you do with the control arms.

Also, if you set up your control arms properly, they are not in bind at ride height.

Ok, that straightens me out (no pun intended). It makes sense you can’t twist a solid axle with a CA that’s the wrong length. The only issue could be your CA’s being in a bind if they’re set up incorrectly. Thanks!

 

[Rickyd]

I run a normal toe of about 1/8". I run the castor at around 7. I've not had issues like Tox described.

I'll keep an eye out for a thread on your brothers Jeep.

Thanks for the info. Close to his #'s. Some theory to learn and measurements to take soon!

 

[Rickyd]

Correct, typically manufacturers set slightly higher caster on the passenger side to correct for road crown.

Here's the factory alignment specs for TJ/TJU (LJ)
(notice the max difference for caster)
View attachment 412041

https://www.wanderingtrail.com/Mech...djust_Repair/Steering_Alignment/Alignment.htm

It was surprising to learn that tj's have more caster on the drivers side. I had been worried my front rubi axle spun a tube in the wreck that removed some brackets.
Not sure why its the case?

 

[reddvltj]

It was surprising to learn that tj's have more caster on the drivers side. I had been worried my front rubi axle spun a tube in the wreck that removed some brackets.
Not sure why its the case?

I have no idea if that is a factory design thing or if it's luck of the draw. If someone could come up with a factory spec showing that the factory did indeed engineer more caster on the left than the right, then maybe I could be a little more amenable to the idea.

Havng zero cross caster (+7° RT&LT), a vehicle will drive straight on a perfectly flat road and drift right on a "normally" crowned road. Having half a degree more caster on the left is going to make it prone to drifting to the right on a flat road and with average road crown, it's going to steer to the right.

 

[Rickyd]

I have no idea if that is a factory design thing or if it's luck of the draw. If someone could come up with a factory spec showing that the factory did indeed engineer more caster on the left than the right, then maybe I could be a little more amenable to the idea.

Havng zero cross caster (+7° RT&LT), a vehicle will drive straight on a perfectly flat road and drift right on a "normally" crowned road. Having half a degree more caster on the left is going to make it prone to drifting to the right on a flat road and with average road crown, it's going to steer to the right.

Yeah its odd.every rig I've aligned was given .3-.5* more on the pass side if i could.I keep finding tj alignment printouts online with more caster on the drivers side. Could just be sloppy welding.not like jeep would ever do that.....

 

[Wildman]

Thanks for the info. Close to his #'s. Some theory to learn and measurements to take soon!

What axle is he running? And how is his steering setup? Not to clog up Jeff's thread.