BigC9164

I am at 3inches of lift and have done all the necesary mods to go higher. Trackbar, sye, driveshaft, and brakelines. I eventually want to go to 5" or lift on 33s with long arms.
I am saving up for a long parts list including JKS ACOS, RC shackle relocations, and bilsteins. And either frankZ long arms or RC long arms. I plan to do all of this when it is time for new tires.
my question for you guys is this... Can I run my RC series II fixed lower and stock upper arms at 4.5inches of lift untill I upgrade to long arms?
They are not adjustable but I THINK they may be a tad longer than the stock lower arms. I obviously won't be wheeling too hard with these untill I get long arms.
Thanks for the help guys!

Lyon

You can but not for long. I did the same thing. The pinion angle was terrible on my 99 when running stock uppers and RC's fixed lowers. I waited too long to get the uppers and I now have play in my pinion bearings and front slip spline shaft because of it. You'll notice some vibes too but probably at higher speeds.

ericfx1984

interesting.... if the lowers are set correctly, stock uppers should be almost perfect at 4.5"

did you shim the lowers to make up the difference?

Lyon

No, that's the thing. I had NO caster shims in whatsoever. So I couldn't make any more adjustments. I measured the angle and it was 8 degrees difference from the pinion to the front shaft. And that's on the High Pinion! And it is even worse when flexing like mad in the front. I consider myself lucky I never broke a pinion strap or ear off the pinion itself. I have extended shocks in the front and always run disconnected on the trail. It flexes pretty nice. I just got upper adjustables for it and got the angle back perfect now. Had to adjust the toe slightly since the caster changed. ( I had some wandering) and it's all good now. Problem is, I waited too long and now have to pull the axle apart and do the pinion bearings. And it added play to my slip spline. I guess it's not a big deal since both my axle seals are leaking now as well. Looking in to tube seals now as well.

BigC9164

I was more concerned with the steering geometry being changed with the caster than the pinion angle. 8 degrees does not seem like all that much. with the 3 u joints in the drive shaft that means each u joint is only responsible for 2.5 degrees. that seems fine. not much different than my rear shaft. are you sure your pinion gear just wasn't loose to begin with?
Will it affect my steering at all?

Lyon

Yeah, I had the same thinking as you did with the steering geometry. Like I said, after getting the pinion angle back I did have some steering wander. If you look at numerous threads, alot of people had said the same thing as well. I did another measurement and adjusted the toe about an addition 1/8 inch in and wandering was gone.

I didn't realize how important the pinion angle really was in the front until I started chasing a vibration for weeks. I too had the 3 inch RC lift then upgraded to the 4.5 inch. That little inch and a 1/2 changes everything. I didn't think it would change the angles that much either running the stock uppers but it did.

No, I had no play what so ever in the front pinion before. I've had the front end apart before since I installed the Spartan locker and one other time to change the inner axle seals.

I don't know that the U-joints take 2.5 degrees each. I don't make them but I'm thinking since 2 are on one side it doesn't work that way. This is how the shaft is supposed to line up.

http://www.xjtalk.com/showthread.php?t=7299

http://www.stu-offroad.com/axle/pinion/pinion-1.htm

dogger15

just get the 4.5"x series rc lift and get shackles instead of the full spring packs thats what i plan and already have a 3" lift

Lyon

His front end will sit much higher than the rear if he does this. RC's 3 inch springs are much softer. I ran mine like this and all it does it flatten out the leaf springs. BUT, it does make it flex much nicer!!

BigC9164

okay thanks guys!

And i have the 3" kit on now and am pleased with it and it is the perfect kit to modify and build a pone in my eyes. I cant wait till my tires wear out ao i can have an excuse to do my dream lift!

adamk

Well if youre only going to 4.5 inches, I dont see why having stock uppers would cause all that pain. RC 4.5" kit and RE 4.5" kit both use stock uca's and they dont have too many problems with vibs up front. I know you said you'll just be running your 3" lca's so I can see that making the front pinion angle a little steeper but not by much.

please jump in and correct me if I'm mistaken somewhere. I'm in the process of going up another 2" from my 3" lift and that was all my understanding

Lyon

http://api.viglink.com/api/click?for...2Fpinion-1.htm

adamk

understood. guess the point i was making is that if the manufatures sell kits that still use the factory upper arm, then there must be some kind of leeway as to the pinion angle.

Lyon

Oh, there is no doubt you can drive them this way. You're right about that. But you'll have problems with it. Mine is a prime example. I believe it's a marketing tactic. They make more money in the long run selling parts you need down the road instead of just buying them the 1st time. If they made the "perfect" lift set up, you'd never need anything else. Except for when you break something.

adamk

Haha nicely put. I just recieved my spacers and shackles to go up another 2" today so I will be installing them with my stock upper and extended lowers for the time being. But, ill end up with adj. uppers and then lowers.

Lyon

Awesome! you'll be sitting pretty high when that's done. I agree with getting the adjustable uppers first since you have SOME adjustment with the caster brackets if needed. Post pics!!!