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Topic Review (Newest First)
12-14-2014 05:20 PM
m4j2t
Quote:
Originally Posted by kjeeper10 View Post
Honestly-with a 4 door-You may not need caster corrected. It's not going to be life or death if the steering is a little flighty.
control arms or drop brackets can be installed easily later on. Id take the wait and see approach and save your money on alignment/caster angle.

Jadmt will second this, and his rig is the reason I'm going to start with only the RK 1.5" springs. Hie is all in spec with all stock control arms.

I'm currently putting together my gear. Swapping the stock rubicon bumpers for heavier 10A bumpers/winch combo and an AEV tire carrier (Craigslist score!). All I'm going to do to the suspension is RK 1.5" coils and 9000xls shocks with the teraflex rear swaybar relocator. (Just for starters)
12-14-2014 07:12 AM
kjeeper10
Quote:
Originally Posted by Vaunswa View Post
Looking at 4 wheel installing the 1.5" RK coils with Rancho 9000's they said alignment cost would be 150 instead of 80 and $35 for some caster parts. Wouldnt they be better off installing the geometry brackets instead of a new caster and additional alignment costs? They explained that to get it correctly after higher coils theres additional work drilling into the frame with caster, etc. I didnt understand what he was saying after that but I have not heard any of this mentioned on the forums before so thought I would consult with the pro's. Sorry for the newb questions but I dont want them pulling a fast one on me and would rather take care of the problem correctly.
He wants to install cam bolts (aka caster bolts). They only provide a small amount of caster change and require squaring out the lower CA Mount holes.
Honestly-with a 4 door-You may not need caster corrected. It's not going to be life or death if the steering is a little flighty.
control arms or drop brackets can be installed easily later on. Id take the wait and see approach and save your money on alignment/caster angle.
12-14-2014 06:31 AM
Vaunswa Looking at 4 wheel installing the 1.5" RK coils with Rancho 9000's they said alignment cost would be 150 instead of 80 and $35 for some caster parts. Wouldnt they be better off installing the geometry brackets instead of a new caster and additional alignment costs?
They explained that to get it correctly after higher coils theres additional work drilling into the frame with caster, etc. I didnt understand what he was saying after that but I have not heard any of this mentioned on the forums before so thought I would consult with the pro's.
Sorry for the newb questions but I dont want them pulling a fast one on me and would rather take care of the problem correctly.
12-13-2014 09:55 PM
kjeeper10
Quote:
Originally Posted by Swampdigger View Post
Finished up the alterations and locked everything down, Handles as good or better than new. Handles bumps and highway speed with no issue. Just got to center the steering wheel tomorrow. Thank you for your knowledge and help.
Nice glad to help.
12-13-2014 08:57 PM
Swampdigger Finished up the alterations and locked everything down, Handles as good or better than new. Handles bumps and highway speed with no issue. Just got to center the steering wheel tomorrow. Thank you for your knowledge and help.
12-13-2014 01:10 PM
kjeeper10
Quote:
Originally Posted by Swampdigger View Post
Again many thanks and you have been most helpful
Anytime my friend.
12-12-2014 11:59 PM
Swampdigger Again many thanks and you have been most helpful
12-12-2014 11:22 PM
kjeeper10
Quote:
Originally Posted by Swampdigger View Post
The jku is now setup to carry a plow. I put on sumo spring bump stops and coil spacers. I plowed 14 years with a tj. Anything you suggest to do or watch out for with the jk ?
Good move with the spacers. I don't foresee any issues.
12-12-2014 09:32 PM
Swampdigger The jku is now setup to carry a plow. I put on sumo spring bump stops and coil spacers. I plowed 14 years with a tj. Anything you suggest to do or watch out for with the jk ?
12-12-2014 08:02 PM
Swampdigger Thanks. I'll try that and lock things down.
12-12-2014 05:09 AM
kjeeper10
Quote:
Originally Posted by Swampdigger View Post
Just new around here . I have a 2012 jku on 285/70's. Just installed Rk !.5 inch lift with adjustable lcs and front trackbar. After alignment the caster numbers are 5.0 for the left front and 4.4 for the right front. Is that ok or should they be closer.
A little cross caster is ok. A few degrees more on the driver side is normal to combat road crown. You have it opposite.
Too much cross caster is putting some stress on the axle, bushings. I would turn the left arm in a half a turn. 4.4-4.5 is where you want to be.
12-11-2014 10:17 PM
Swampdigger Just new around here . I have a 2012 jku on 285/70's. Just installed Rk !.5 inch lift with adjustable lcs and front trackbar. After alignment the caster numbers are 5.0 for the left front and 4.4 for the right front. Is that ok or should they be closer.
12-11-2014 06:50 PM
kjeeper10
Quote:
Originally Posted by Niche650 View Post
Thanks again kjeeper10! I'll measure using your method to double check. I decided that ultimately I'm going to adjust the arms to shorten them up. It will make the ride even smoother and give me additional clearance for the sway bar. If it puts more stress on the driveshaft and it fails, well I guess that is just an excuse to upgrade
Well you have Some room .. Go for it.
12-11-2014 06:42 PM
Niche650 Thanks again kjeeper10! I'll measure using your method to double check. I decided that ultimately I'm going to adjust the arms to shorten them up. It will make the ride even smoother and give me additional clearance for the sway bar. If it puts more stress on the driveshaft and it fails, well I guess that is just an excuse to upgrade
12-10-2014 10:13 PM
kjeeper10
Quote:
Originally Posted by Niche650 View Post
Front lowers were set to 23 & 1/8". The axle is centered, measured by putting a vertical level on the tire sidewall and tape measure on the fender flare. Any chance that the sway bar will contact the spring when flexing up and down?
23 1/8 is right on.

Measure from the top of the coil perch to the level. I like to use a mold line or common point on each tire.

Do you have a picture ?
12-10-2014 08:50 PM
Niche650
Quote:
Originally Posted by kjeeper10 View Post
You're welcome

Good work on setting the jeep up. Alignment looks pretty good.

Do you remember what you set the front lowers to?
Shortening the uppers will rotate the pinion down which will increase caster numbers. Caster is on the light side, but IMO. if the jeep handles fine .. Leave it. The driveshaft will be happier where you have it at.

How is axle center (Track bar) ?
Will shifting the axle to the passenger side fix the issue ?
Front lowers were set to 23 & 1/8". The axle is centered, measured by putting a vertical level on the tire sidewall and tape measure on the fender flare.

Any chance that the sway bar will contact the spring when flexing up and down?
12-10-2014 08:14 PM
kjeeper10
Quote:
Originally Posted by Niche650 View Post
Firstly thanks for sharing this information kjeeper10! It was instrumental in helping me to get my lift situated. I finally finished up my RK 2.5 x-factor this weekend and have attached the report from the alignment shop. It took me quite a bit of time removing/installing/measuring and pulling the front apart 3x before I was somewhat satisfied. However, my front sway bar is very close to the spring on the passenger front. I'm thinking of shortening my front upper arms 1 or 2 complete 360 degrees turns (which from what I've read, 1 turn = .5 degree caster). It actually already drives much better than stock! Less wandering over bumps on the freeway. What do you say? Leave as is, or 1 turn in, or 2 turns in? Thanks again!
You're welcome

Good work on setting the jeep up. Alignment looks pretty good.

Do you remember what you set the front lowers to?
Shortening the uppers will rotate the pinion down which will increase caster numbers. Caster is on the light side, but IMO. if the jeep handles fine .. Leave it. The driveshaft will be happier where you have it at.

How is axle center (Track bar) ?
Will shifting the axle to the passenger side fix the issue ?
12-10-2014 07:59 PM
Niche650 Firstly thanks for sharing this information kjeeper10! It was instrumental in helping me to get my lift situated.

I finally finished up my RK 2.5 x-factor this weekend and have attached the report from the alignment shop. It took me quite a bit of time removing/installing/measuring and pulling the front apart 3x before I was somewhat satisfied.

However, my front sway bar is very close to the spring on the passenger front. I'm thinking of shortening my front upper arms 1 or 2 complete 360 degrees turns (which from what I've read, 1 turn = .5 degree caster).

It actually already drives much better than stock! Less wandering over bumps on the freeway. What do you say? Leave as is, or 1 turn in, or 2 turns in?

Thanks again!
11-03-2014 10:06 PM
kjeeper10
Quote:
Originally Posted by MnJK View Post
Great thread! Have a smallish lift right now (2.25" - 2.5" net lift). I do mostly trail riding and rock crawling so would go with CAs for clearance rather than drop brackets. Given the small lift, may not need much if any adjustment but am very curious now so will measure the angles! Been reading through some other threads to understand UCAs and LCAs and which to do based on lift size. Am curious what your thoughts are on these comments: 1. The upper control arms help to correct pinion angle due to most companies arms are longer than stock arms to begin with. So with the uppers being adj. you will be threading them out to increase the angle. If you were to do the lowers you would be turning in the theads in trying to make the arms shorter which with most arms will not have enough adjustment. 2. If you do need a pair of arms for the rear to adjust for pinion angle, go with rear uppers. If you go with lowers, you will have to shorten them, decreasing your wheelbase and moving your tire closer to the pinch seam. With the uppers, you will be moving your axle further away from the pinch seam. Now, it is probably a nominal amount of distance because you are rotating the axle rather than moving it, but better to push it away than pull it in.


In the front you're adjusting for caster. Longer lowers or shorter uppers. I know MC uses front uppers in their basic kit to adjust caster. The upper arms are going to be shorter than stock.

You pretty much got the rear correct.
One thing .. Uppers alone won't have any affect on wheelbase.

Most aftermarket arms are stock in length with 1" or so adjustment either way.
(Example) @ 3-4" of lift ... all it takes is 1/2"-3/4" to position the axle and set the angles.
RK moves the axle back 1". Their rear arms are longer. currie/synergy are stock length +/- 1" or so.
11-03-2014 09:03 PM
MnJK Great thread!

Have a smallish lift right now (2.25" - 2.5" net lift). I do mostly trail riding and rock crawling so would go with CAs for clearance rather than drop brackets. Given the small lift, may not need much if any adjustment but am very curious now so will measure the angles!

Been reading through some other threads to understand UCAs and LCAs and which to do based on lift size. Am curious what your thoughts are on these comments:

1. The upper control arms help to correct pinion angle due to most companies arms are longer than stock arms to begin with. So with the uppers being adj. you will be threading them out to increase the angle. If you were to do the lowers you would be turning in the theads in trying to make the arms shorter which with most arms will not have enough adjustment.

2. If you do need a pair of arms for the rear to adjust for pinion angle, go with rear uppers. If you go with lowers, you will have to shorten them, decreasing your wheelbase and moving your tire closer to the pinch seam. With the uppers, you will be moving your axle further away from the pinch seam. Now, it is probably a nominal amount of distance because you are rotating the axle rather than moving it, but better to push it away than pull it in.
08-28-2014 12:19 PM
kjeeper10 No .. The flat circles are just easier to get a quick measurement.
True pinion angle is measured off the flange area/output yoke.
08-28-2014 11:52 AM
DOMINUS
Quote:
Originally Posted by kjeeper10 View Post
Flange area/u-cap is the best area. That will give you true pinion angle. From that number -caster.
That's the area you had circled in your pics correct?
08-28-2014 08:57 AM
kjeeper10
Quote:
Originally Posted by DOMINUS View Post
I'm going back on Saturday to finalize payments but I will ask him to put the angle finder directly on the pumpkin.
Flange area/u-cap is the best area. That will give you true pinion angle. From that number -caster.
08-28-2014 07:51 AM
DOMINUS
Quote:
Originally Posted by kjeeper10 View Post
8/9 puts your driveshaft at a extreme angle. The higher the lift ... It's worse.
Measuring at the lower C is not accurate. That area is cast and not a machined area.
Fwiw .. back when I was running 6* caster and wrecked my front DS. The lower C's measured 6 on the passenger and 8 on the driver side.
It's possible the measurement he got is wrong. I would still confirm. You don't want to cause harm to your DS/tranny.

Take a side shot of your pinion output/DS
8 should be easily confirmed
I'm going back on Saturday to finalize payments but I will ask him to put the angle finder directly on the pumpkin.
08-28-2014 05:33 AM
kjeeper10 8/9 puts your driveshaft at a extreme angle. The higher the lift ... It's worse.
Measuring at the lower C is not accurate. That area is cast and not a machined area.
Fwiw .. back when I was running 6* caster and wrecked my front DS. The lower C's measured 6 on the passenger and 8 on the driver side.
It's possible the measurement he got is wrong. I would still confirm. You don't want to cause harm to your DS/tranny.

Take a side shot of your pinion output/DS
8 should be easily confirmed
08-28-2014 01:16 AM
MOPWR2U I don't think your frame is bent at all. The frame on a JK is super strong, more so than most truck frames, in fact. Centering your axles will only require track bar adjustments, and correcting caster will only require adjusting your control arms.
08-28-2014 01:05 AM
DOMINUS
Quote:
Originally Posted by madmax4499 View Post
Like on a frame machine? I agree 1/4 is a lot. I would do 1/4 on a log truck. Stick with an 1/8 and keep an eye on tire wear.
Well not exactly a frame machine but he said he'll use ratchet straps to pull stuff while he adjusts everything. I don't think my frame is that bent. I've only been off roading 3x at Rausch and it has always been the 101 course. Easy stuff. No frame twisting articulation going on there.
08-28-2014 01:01 AM
DOMINUS
Quote:
Originally Posted by kjeeper10 View Post
I would not do 1/4 with toe. That will literary chew the tires right up.
Man ... Hope everything works out for ya.
Ok I'll tell him to leave it at 1/8". I noticed that he didn't use the pumpkin to get the caster. He used a spot right on the inside of each wheel that to my untrained eye seems to correlate to the pumpkin. Are 8 & 9 even feasible numbers for caster? If these members are true how come in not experiencing worse effects of bad caster?
08-27-2014 06:59 PM
madmax4499
Quote:
Originally Posted by kjeeper10 View Post

I would not do 1/4 with toe. That will literary chew the tires right up.
Man ... Hope everything works out for ya.
Like on a frame machine? I agree 1/4 is a lot. I would do 1/4 on a log truck. Stick with an 1/8 and keep an eye on tire wear.
08-27-2014 03:56 PM
kjeeper10
Quote:
Originally Posted by DOMINUS View Post
Kjeeper10 I found a guy locally that does everything to Jeeps. Turns out my Jeep is all twisted LOL. Looking at it with the naked eye it looks good but the measuring tape tells a whole different story. The front axle is off to the left and the rear is off to the right. My caster on the left is at 8 and on the right is at 9. Funny thing is he drove it and said that it drives fine for being so off. I guess the front is somehow canceling out the rear and everything is incorrectly correct LOL. He also said that my toe should be more aggressive with 37's because they tend to want to do their own thing. He suggested 1/4" toe in. Anyway at the end of the month I go on vacation and I'm leaving it with him while I get some much needed rest. I'll be doing 5.13 gears, Reels 1310 drive shafts and while its there he'll pull, twist, tug and yank everything into spec as far as caster, toe, alignment and what not.
I would not do 1/4 with toe. That will literary chew the tires right up.
Man ... Hope everything works out for ya.
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