dukie564

I realize this is quite specific, but I'm running shackle relocation brackets with Dakota shackles (total lift from this combo is ~1 1/2" at the rear of the spring packs). I will be installing ~3" lift springs shortly.

I hate TC drops, and don't see the need for a SYE at 4.5" on an older XJ...

Am I looking at this correctly that the shackle brackets + extended shackle will function just like a degree shim would - ie. points my pinion angle up?

If this is true, if I get vibes after the lift then I would need to install a shim backwards (thick end forward) to counteract the effects of the lift/brackets/shackle and bring my driveline angles back into spec?

Anyone running the shackle brackets + slip yoke driveshaft have any input?

no rdplz

It won't position your pinion as much as you think. The whole idea of the brackets is to allow for a better shackle angle so the ride and flex are better. For 4.5", you'll want 6* shims with the skinny end forward. Fat end forward points the pinion down.

dukie564

i'm not going to run a SYE or TC drop, so i don't want to angle my pinion up

no rdplz

Pointing your pinion down will increase the amount of binding on the axle u-joint. When you lift it, the DS angle will increase, creating more bind. You need to point the pinion up to relieve that binding. A t-case drop relieves the binding from the other end by lessening the DS angle, making shims unnecessary. An SYE allows a longer DS which lessens the DS angle, and also incorporates a CV joint, relieving u-joint binding. (I'm sure you know how they work, I'm just putting it in here for anyone who is searching the topic for knowledge) Point is, if you want to not have vibes at 4.5" and plan to use the OE slip-yoke style shaft without a t-case drop, you want you're pinion to point up more, not down.

dukie564

but for the ujoints on either end of the stock shaft to "work", don't they need to have the same angles running though them - ie. shouldn't the TC output and axle pinion be as close to parallel as possible (save a bit for axle warp)?

no rdplz

Sorry, you're right, I kept picturing an SYE set up where the axle pinion needs to be center-lined with the shaft instead of a non-SYE set up. Wow, total tard moment. Yes, for a simple, non CV style shaft, the axle pinion and t-case output shaft should be parallel with each other. Since you're not running a t-case drop, then yes, fat end forward on the shims so the pinion gets pointed down to make it parallel with the t-case output shaft. I would still run 6* shims when you get the 3" coils and leaf packs though.

So basically you're original line of thought is correct and I've proven myself to be a tard by telling you how to run a SYE setup instead of a non-SYE set up. I shall now commence with the following......

You want this:


not this (which is what I was picturing in my head for some reason):

dukie564

ROFL! That made my day

TheJerm

I agree too. I run flipped s10 springs with relocation boxes and lift shackles to get ~5", the pinion is pretty much inline with the DS. I dont recall ever really having vibes from it tho but installed a SYE anyways b/c the DS was too short and caused other issues but no vibes (AW4 DS in AX15 XJ).

no rdplz

Glad I could make you're day better dukie!

dukie564

what do you agree with Jerm..?

So you are saying that you ran the 5" and the TC output and Pinion were about the same with no shims or drops?

TheJerm

oh duh, umm I dont know why I put that in there. lol

dukie564

oh wow this thread is giving me a headache now lol.

Thanks for the "help" guys

no rdplz

Lol, no problem dukie! In all seriousness though, 6* shims with the fat end forward should give you what you need.

dukie564

seems like a lot. I have some ones i think are 2.5* that i'll try.

no rdplz

6* shims are what's recommended for 4.5". Try the 2.5* since you got 'em and see where it sits. If there's no vibes, call it good!