Okay, I'm building up a YJ with a 9" in the rear. I'm using RE's heavy duty spring over leafs, and I decided to try out T&T's new U-Bolt eliminator setup (that's the crazy looking perches).

Also for the record, the reason why the rear perches are so tall is because I was trying to compensate there for the added lift I'm going to get up front from the shackle reversal I'm doing. The front perches aren't as tall.

Anyway, here's what I'm worried about. I'm no 9" expert, so I'm wondering what you all think about my angles. I know my pinion angle is pretty damn steep and that's what I'm worried about. I'm worried that the pinion might not get the proper oil among other things.

Pics are here: Clickety (http://www.phatserver.net/temp/list444.php?path=YJ/)

What do you guys think I should do? Think it doesn't look all that bad? Think I should rotate my pinion down and make the driveshaft angle a little steeper?

Also, the whole front end is on Jack stands, so the whole Jeep may come down a little in the front.... which would also help, but the rig is sitting pretty level even on the stands.

Thanks guys.

Not an "expert" but the angle doesn't look that bad.

What angle is the pinion at now? The springs look new, so assume they will sag a little and lower the rig. Looks about 3" too tall to me. Also, from the way it looks you will be running a CV rear shaft. Always set the pinion angle a few degrees below because when you get on the gas the pinion comes up.

15 derees maximum recomended on nines ,you look like you have more ,you also will get some axle wrap under torque which looks like it will over extend your front drive shaft joint at the transfer case so i would check on that at full droop

angle does look a little steep

Whats your disk brake set up in the 9

how do you like the tnt u bolt eliminators

Duff, I don't know where the discs came from to tell you the truth, I bought the axle already built. Don't know much about the eliminators yet cause the rigs not done :D

Guys: I didn't measure the actual angle yet, but I will. First I've heard of the 15deg rule of thumb so I will keep that in mind.

The springs are brand new, and right now the rear shackles are almost perfectly vertical, so they must sag a little.

I do plan on runnng a CV shaft. I will have it custom built once I'm ready. I also plan on running a traction bar, so I shouldn't get too much wrap.

I will measure the angle tomorrow and if it's over 15 degrees, I will nock it down and see how it looks.

I'm thinking that since I'm going to be running a CV shaft, plus the little bit of wrap that I'll get, I should be okay if I knock the angle down a bit.

Edit: .... and if worst comes to worse, I can get another set of spring perches that don't have so much lift. That will definitely help the angle. I just don't want my rig to sit nose high.

Edit: .... and if worst comes to worse, I can get another set of spring perches that don't have so much lift. That will definitely help the angle. I just don't want my rig to sit nose high.

Nose high is better for clearance... the stupid 9" pinion is so freeking low that it wants to drag over everything...

Never heard of the 15 degree deal, but mine is every bit as angled as your pic, rear tj, and haven't had any problems, the damn thing holds a gallon of lube. Mine is trail only and maybe at a lot of highway speed , could be a oiling issue, dunno.

Why dont you just grind out the perches a little bit, then reweld them to the axle?
That would effectively lower the ride height, and lessen the pinion angle too...
Just a thought. :D

Nose high is better for clearance... the stupid 9" pinion is so freeking low that it wants to drag over everything...

There are remedies for that problem... www.truehi9.com

I am running the RE springs as well on my sprung over CJ. Went with 5-leaf in the front and 6-leaf in the rear. The five relaxed enough that there was a noticeable difference in height. I originally thought of the 5's in front for a softer ride and the 6's in the back to combat axle wrap issues. Ended up switching the springs. Now I run the 6's up front and the 5's in the rear. Either way you need a traction bar. You will notice very little relaxation in the 6 leaf springs. I would say point the pinion straight at the t-case. The springs may set just enough to give you 1-2 degrees at most when they break in. I ran my springs for a season and went easy on the pedal when pointed uphill to ease up on the axle wrap, then set my pinion right at my t-case, re-welded the perches, and put the traction bar on.

If it's a concern, you can go with a nodular third and have the pinion support drilled for better pinion oiling.

I've never had mine at high speeds, but my pinion is about as high as that one.

angle does look a little steep

Whats your disk brake set up in the 9

how do you like the tnt u bolt eliminators

they are ford explorer breaks which curry sell alot on their axles, i have them but not for long

http://i2.photobucket.com/albums/y39/Plato2k5/9indisc.jpg

http://i2.photobucket.com/albums/y39/Plato2k5/9indisc2.jpg

my nine with discs :)

oh also you mite wan't to get ride of the 90* edges on your spring plates...i was told this will help cause spring brakage. Not sure how true it is but take it for what its worth

otherwise...looks good!

I ran my pinion at 20 degrees for 3 years with no problems. Speeds up to 70 mph with no oiling issues.
I'm building a new housing now with about 23 degrees. We'll see how it does, i'm hopeing a couple more degrees won't matter.

I can't imagine a 9" starving for oil. The fill plug is WAY higher than the pinion bearings.

I have a Currie 9 in the back of my CJ at a 24 degree pinion angle. With over 10,000 highway miles on it, I'm pretty damn sure its ok.

Leave it alone, its fine as is.

Park on a small incline with the nose pointed downhill and it will allow you to overfill the diff a tad. It doesnt have to be steep, a mild sloped driveway will do.

I ran atleast that steep (possibly steeper) on a 9" for years as a daily driven wheeler. It will be okay.

There are remedies for that problem... www.truehi9.com

'cuse i got 1500 laying around :D

Ill continue to drag my pinion till oppurtunity knocks...

Thanks for all the suggestions guys. I'm glad to hear it should be okay.

I ended up rotating it down slightly yesterday, plus I got the front end on the axle and put the whole rig on tires. Once I did all that, the angle of the rearend got quite a bit better. So I should be good to go. Thanks guys.

I run mine at an angle like that with no problems. Since your still building though now is the time to shave that 9".

Can you shave a 9" effectively without having to remove material from the ring gear? Sorry about the n00b questions.

I thought about that actually, but for some reason I was more worried about trussing it. Seems everybody trusses their 9". Is that something that should be done? Or is it just one of those things that people do because they can :D

I will be re-gearing later, so I will probably wait to do the shave job 'till then. I'd rather spend my time on getting the damn thing rolling down the road under it's own power for now.

http://www.projectxj.com/mods/shaved.9inch.htm

Pretty good writeup here