Angle check on aisle 3.....

OK, this photo was SUPPOSED to include the pumpkin but didn't so you'll have to trust me on my angles.....

This is my 89' XJ w/ 4.5 RE lift, AW4 and D44 in the rear. Shown with front driveshaft in rear location (I plan to clean it up and rejoint). 2° shims installed.

I understand my pinion should be pointing at the back of the transfer case and was wondering how I can achive that given the large variation in the angle. Biggest shims I can find are 8° and from the looks of things, I could use 12°.

Also, please take a look at that driveshaft. I was hoping to use a second front driveshaft for the rear, but it looks a tad short. I understand that a front out of a Grand Cherokee may fit. I've got 34-1/8" from TC to Axle yake ear center line.

i wouldnt go over 8* if even that, if its that bad and the 8 degree shim doesnt work, ul just have to cut off the perches, angle the rearend how you want it, and weld the perches back on...

Your slip yoke looks like it's all the way out. Drive shaft maybe to short. You show 12* to be straight at the TC, but you want to be 2-3* below to compensate for axle torque. 12*-3*= 9*, Try the 8* shim and see if it vibrates. It'll probably be ok.

8* should work fine. defintely put all new joints in whatever shaft you end up with. what application is the front shaft from?

all that clean painted undercarriage and an old rusty drive shaft lol the rig looks like its pretty sweet by the way. yea i forgot about that whole torque thing. 8* shim should be good, just tighten it down good n tight

You might want to try 6's,with a CV shaft you get almost a x1.5 multiplier in effective change.

rocklandxjer said:

all that clean painted undercarriage and an old rusty drive shaft lol the rig looks like its pretty sweet by the way. yea i forgot about that whole torque thing. 8* shim should be good, just tighten it down good n tight

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LOL! Yeah, it was hard to put that old rusty thing up there last night. This is the front shaft from my 89' installed in the rear. After researching here, I'll be looking for a ZJ front shaft to replace this, since I hear they are longer and I can get one at the local J-yard. Sounds like 8° may be just right.....

I have no idea if this puppy vibrates yet. It hasn't been on the road since I bought it. I started with the engine rebuild, took a look at how the previous owner had done everything, and decided it was time to go thru the whole vehicle (axles, Trans, T-case, rear end). I thought at least the gas tank was good.... until I peeked under the rubber dust shield covering the tank (it sure ain't a skid) and realized why my 20 gallon tank held only 18 gallons.

I think I've turned every nut and bolt on this vehicle at least once (or will in the next few weeks)

RCP Phx said:

You might want to try 6's,with a CV shaft you get almost a x1.5 multiplier in effective change.

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Huh? that only gives me 4 more degrees. (there's a 2° shim there already)

As the pinion angle increases(rotates up),the driveshaft angle will decrease.Your short by about 8.5* now(taking in account axle wrap),a 6* shim will net about 9* of overall change.

RCP Phx said:

As the pinion angle increases,the driveshaft angle will decrease.Your short by about 8.5* now(taking in account axle wrap),a 6* shim will net about 9*.

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OK, how does a 6° shim = 9° ? Oh, wait a minute, is this that 1.5X thing? I think I may need to read that Driveline 101 post again.....

RCP Phx said:

As the pinion angle increases(rotates up),the driveshaft angle will decrease.Your short by about 8.5* now(taking in account axle wrap),a 6* shim will net about 9* of overall change.

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it doesn't matter what the driveshaft angle is, he's trying to point it at a fixed location.

BrettM said:

it doesn't matter what the driveshaft angle is, he's trying to point it at a MOVING location.

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Yeah,the driveshaft,and it moves when the pinon does!
A 6* shim should make the pinion at 18* and the driveshaft about 20.5*.

Hmmmmm..... sounds like there's a debate on what I thought was a simple subject. I think I'll check back after my flight tommorow (got fly for bid'ness)