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-   -   Alignment change ride? (http://www.wranglerforum.com/f274/alignment-change-ride-264936.html)

gorillahydrographics 08-23-2013 09:21 PM

Alignment change ride?
 
I have the RE 3.5 short arm super flex. After the lift was installed zi drive it for 2 days and the ride was pretty smooth.

I then took it in to be aligned and the ride seems very rough now.

I was not there for the alignment so I can't say what the caster is. I asked him how he determined the caster when I dropped it off and his answer was whatever the computer tells him.

Could the caster effect the ride if it's not enough?

Theairhead 08-23-2013 09:23 PM

What kind of shop did you go to? What kind of control arms are you using? Tire pressure affects ride as well.

gorillahydrographics 08-23-2013 09:27 PM

It's an all around mechanic shop. The arms are RE arms that come with the super flex lift.

I know it's not tire pressure ...Iam running 35s @ 28 psi.

Theairhead 08-23-2013 09:32 PM

I'd go back and ask for the alignment sheet or ask about the caster angle at least and post back here. I don't know the right numbers now, but I'm sure someone is more knowledgeable than me.

gorillahydrographics 08-24-2013 03:15 PM

Didn't now on the alignment machine it's showing 3 degrees caster.

Nobody seems to be able to tell me what's factory spec tho.

Theairhead 08-24-2013 03:25 PM

That sounds about right. Whats the spring rate

gsn 08-24-2013 03:34 PM

Quote:

Originally Posted by gorillahydrographics (Post 4115889)
Didn't now on the alignment machine it's showing 3 degrees caster.

Nobody seems to be able to tell me what's factory spec tho.

Factory spec is 4~4.2

gorillahydrographics 08-24-2013 03:52 PM

Ya jeep dealer here is telling me anywhere between 4 and 6 with the amount of lift currently.

With the lower arms being fixed is that achievable ?

gsn 08-24-2013 03:57 PM

Quote:

Originally Posted by gorillahydrographics (Post 4115970)
Ya jeep dealer here is telling me anywhere between 4 and 6 with the amount of lift currently.

With the lower arms being fixed is that achievable ?

Use the uppers, your kit has adjustable upper control arms, if its actually the 3.5 RE superflex. With amount of lift you have 5 seems like a good angle.

Considering it was an all around mechanic shop, as a precaution, please check the bolts where the lower control arms meet the axle. See if the bolts are actually centered on the washers...

gorillahydrographics 08-24-2013 04:12 PM

Yes that kit is the adjustable upper and fixed lower.

I was under the impression the uppers didn't effect caster...

kjeeper10 08-24-2013 04:33 PM

Do you have a angle or smart phone app?

On both sides of your front pumpkin, there's 2 flat machines circles. You can get a good pinion reading there. Knowing the JK has 6* of separation (caster and pinion) you can determine the caster angle.

For example (stock)
Pinion positive 2* up (88* with angle)
Caster is 4*

Lets say you get 3* on the pinion (87* angle)
Caster will be 3*

Pinion at 0 (90* angle)
Caster 6*

= 6* between the two. I measured mine at 2* and alignment rack showed 4.5* caster.

Was toe changed at all? Sometimes the tires need to find a new wear pattern if the alignment was off.

Also check your PSI

kjeeper10 08-24-2013 04:34 PM

Quote:

Originally Posted by gorillahydrographics (Post 4116008)
Yes that kit is the adjustable upper and fixed lower.

I was under the impression the uppers didn't effect caster...

Both affect wheelbase/caster and pinion.

With uppers and lowers. The lowers center the tire in the well (bump stop concentric with pad)
The uppers are used for caster/pinion

gorillahydrographics 08-24-2013 09:46 PM

Quote:

Originally Posted by kjeeper10 (Post 4116056)

Both affect wheelbase/caster and pinion.

With uppers and lowers. The lowers center the tire in the well (bump stop concentric with pad)
The uppers are used for caster/pinion

Ok, I guess we are going to go in next week and adjust the uppers and get towards the 5-6 degree positive.

kjeeper10 08-25-2013 04:44 AM

Quote:

Originally Posted by gorillahydrographics (Post 4116913)

Ok, I guess we are going to go in next week and adjust the uppers and get towards the 5-6 degree positive.

6* is too much with the lift you have. Caster adds more to the pinion angle. Stock DS won't like it and will eventually fail.
Def can't run 6* with 3.5" lift and a aftermarket shaft.

You need to be 4-4.5 which is essentially stock. Some folks can't even run that and settle with a 3/3 split

Good luck

kjeeper10 08-25-2013 04:53 AM

Fwiw

When installing CA's. with the front lowers-each side stuffed, the bumpstop should center on the pad. Arms are usually set 23-231/8" eye to eye.
Uppers set pinion and caster. Remember, the arms won't always be the same lengths due to manufacturing differences. Caster/pinion is set with a jack under the pinion. One side bolted up to hold orientation, then the other so there's no binding in the bushings.

The rear is similar except caster is not at play. You're only dealing with wheelbase and pinion angle. Lowers center wheel in well and uppers so pinion is a couple degrees lower than the DS. Again .. The BS should be concentric with the pad stuffed.

gorillahydrographics 08-25-2013 08:01 AM

I have the RE front DS. With the ACOS and 3/4 spacer in the rear I might be a little taller.

So your suggestion is to be no more than 4.

jrussblues 08-25-2013 08:45 AM

Did your kit come with the drag link flip?

kjeeper10 08-25-2013 09:25 AM

Quote:

Originally Posted by gorillahydrographics (Post 4117638)
I have the RE front DS. With the ACOS and 3/4 spacer in the rear I might be a little taller.

So your suggestion is to be no more than 4.

RK recommends 4-4.5 with what seems to be most lift heights. If you get vibes rotate both uppers one turn out to rotate the pinion up.

jrussblues 08-25-2013 10:05 AM

Quite honestly, some, or most of the problem is likely with the Acos spacers.

They are causing your jeep to sit higher in the front, which means that in order for the alignment to be set properly to track straight on the road your upper arms are having to be adjusted to a point that they are likely causing some funky flex on the sping.
On the axle side the actual caster is going to be put out of spec to achieve the same means.
Given that the front driveshaft angle takes a back seat to caster on the re cv driveshaft you are now taking that front ds even further out of spec. It would likely work better if you were the same height all the way around. With the other factors involved its likely putting your ds at angle similar to what would be found on a 6-7" lift. That's also going to be sent through all of your steering components. Typically at +4" of lift you want to flip the drag link and modify the track bar angle.
And 3 degrees of caster seems a bit low.

If you want the most cost effective solution would probably be to remove the spacers. The fun way would be to work through the kinks so you can have it set up with the stance you like.

kjeeper10 08-25-2013 11:06 AM

Quote:

Originally Posted by jrussblues (Post 4117987)
Quite honestly, some, or most of the problem is likely with the Acos spacers.

They are causing your jeep to sit higher in the front, which means that in order for the alignment to be set properly to track straight on the road your upper arms are having to be adjusted to a point that they are likely causing some funky flex on the sping.
On the axle side the actual caster is going to be put out of spec to achieve the same means.
Given that the front driveshaft angle takes a back seat to caster on the re cv driveshaft you are now taking that front ds even further out of spec. It would likely work better if you were the same height all the way around. With the other factors involved its likely putting your ds at angle similar to what would be found on a 6-7" lift. That's also going to be sent through all of your steering components. Typically at +4" of lift you want to flip the drag link and modify the track bar angle.
And 3 degrees of caster seems a bit low.

If you want the most cost effective solution would probably be to remove the spacers. The fun way would be to work through the kinks so you can have it set up with the stance you like.

Agreed...
2-3* caster is prob what he needs to keep the TC in one piece. Which is going to kill drivability.

Remove the spacers and raise caster.


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