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I will be ordering a CV driveshatft shortly and I want to get this all correct. Once it is installed to dial in the right pinion angle I need to do what to the upper and lower control arms. I looked and to me it seems...1.) I have to lengthen the uppers to push the diff back to line it up with the transfer case. Thus shortening the lowers as it rolls back. But then again I could argue that...2.) shortening the uppers will pull it up at the angle needed thus lengthening the lowers. The second seems more likely but this is my first lift that required a CV. Please help!
 

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Dig...

All you need to do is lengthen the Upper Control Arms. Don't shorten the lowers if you have that ability. Remember the pinion should be 1 deg lower than the DS. Just use a floor jack to raise the pinion until it is at the desired angle and then turn out the UCA till they meet the holes.

Sean
 

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I agree with Sean and your first observation. :)

Though, I would first adjust the LCA's to center the rear wheel in the wheel well and then lengthen the UCA using Sean's method to rough dial in the pinion angle.

You may have to fine adjust the pinion after all of this once you test drive Ruby. If you have vibrations during acceleration, shorten the UCA's. If you have vibrations during decelleration, lengthen the UCA's.

Ken
 

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Adjust you lower arms so that they are the same length of the stock ones. This is the easiest way to ensure that you axel is even. Take two long bolts and put them through the stock arm and turn out the adjustable to match.
 

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Sean, don't you think it might be better for the LCA's to be a little longer than stock since you loose a little wheel base when lifting the Jeep?

I adjusted my LCA's to 16 3/8" for my 3" lift and the axles centered pretty well in the wheel well - wheelbase is almost exactly to stock specifications and bump stop towers are centered in the springs.

The only problem this created for me was my rear Teraflex shock relocators then made contact between the shock and gas tank so I had to remove them. They aren't needed if the wheel base is corrected and a CV driveshaft isn't being used.

So Dig might want to add a pair of the shock relocators, since he is using a CV, to correct for possible rear spring pad and shock contact issues.

Just some thoughts if he has lower and upper adjustable control arms.

Ken
 

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Ken White said:
Sean, don't you think it might be better for the LCA's to be a little longer than stock since you loose a little wheel base when lifting the Jeep?

I adjusted my LCA's to 16 5/8" for my 3" lift and the axles centered pretty well in the wheel well - wheelbase is almost exactly to stock specifications and bump stop towers are centered in the springs.

The only problem this created for me was my rear Teraflex shock relocators then made contact between the shock and gas tank so I had to remove them. They aren't needed if the wheel base is corrected and a CV driveshaft isn't being used.

So Dig might want to add a pair of the shock relocators, since he is using a CV, to correct for possible rear spring pad and shock contact issues.

Just some thoughts if he has lower and upper adjustable control arms.

Ken
When you flex and stuff the rear tire does it fit nice and perfect or it is contacting the rear of the fender flare. The reason that I don't feel that the lowers should be adjusted is that when the suspenson is compressed and the LCA are stock length every thing falls back into place where it should minus the rotated pinion. I would be curious to see some pix of the arms lengthened and a tire stuffed in the well and the placement of the bumpstop in relation to the spring pad on the axle. I am not Flaming you here Mike I am just curious to see what effects this has seeing as I have not done it. I know that even with the RE lift if you have LCA that are adjustable then you are to set them to stock length.

This is a good topic and I think a lot can be learned with this one...Keep the info coming Mike.. :D

Sean
 

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Sean, I haven't bottomed it out completely yet to see, but it is only about 5/8" longer and since the CA can never get all the way parallel to the frame due to the bumpstop, I'm guessing there will not be any contact issue - minor at best and then that means stock length is very close to contact.

I will check soon and get back to you. I don't have a digital camera yet, spent all my $ on mods, so pictures will have to wait until I shoot a full role of film and save to CD.

I know that there isn't any flame intended, that is why I prefer this forum over others! Discussion and learning is great! I have learned very much from these forums. :D

Have a great day!

Ken

BTW, my name is Ken not Mike :p
 

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Ken White said:
BTW, my name is Ken not Mike :p
Oppssss........I knew that.. Mike is my bosses name and I was talking to him when I replied..Sorry KEN.. :wink:

Sean
 

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Ken White said:
No problem.... I've been called much worse! :shock:

Married???. :wink:

Sorry had to, I learn't a whole new language when I was married.
 

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Now if my wife was calling me Mike, I would be a little upset! :mad:

Actually, after 20+ years in the military, I've been called all sorts of things.

Have a great day Sean and I'll try to get some testing done soon to see how bad the contact is with longer LCA's.

Ken
 

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Discussion Starter #12
OK so according to Ken I lengthen both and Sean says only the uppers. According to my lift instructions I am supposed to lengthen the LCA to recenter so I think Ken may have a good point. I guess only trial and error will tell. THanks for all the info guys!!!
 

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OK, here is what I've learned:

I had adjusted my F/R LCA's to be longer to get my wheelbase back. I did not have any contact issues in the rear when using the stock DS and the extra length helped to reduce the DS angles. However, I was running a MML and BL at the time so I didn't see the contact issues Sean suggested. However, without a body lift, and good bumpstop extensions, I'm sure the possiblity of rear quarter panel damage exists. I did have minor Differential contact when both tires were stuffed when climbing steep inclines.

Now that I have a HAD DC DS and had to rotate the rear pinion, the rear LCA's had to be shortened back to original length to remove Track Bar and Gas Tank Skid contact as well as increased Differential Cover and Gas Tank Skid contact. So Sean is 100% correct in his post about stock rear LCA lengths for a CV driveshaft. I have the Currie rear TB and bracket, so binding might not be an issue with a bracket made for a CV.

I would still suggest to lengthen the front LCA's since I have had no isssues there and it does help with the wheelbase and drivability.

I hope this helps.

Ken
 
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