Question about installing a rearend

[Craig]

stuff i want to get rid of

Just wondering why you should set the angle of your axle at a certain position when installing an axle. If I'm welding on new spring mounts and shock mounts, why not just point the diff straight in line with the driveshaft? Will this affect the alignment? It would eliminate any binding of the u-joints.

 

[jps4jeep]

Cause the ring and pinion will not be properly lubed by the gear oil! eventually the rear end will simply fail you, and you will be up sh#t's creek with out a paddle! I think the rear pinion angle on the YJ's is38 degree's, but check! if possible, you can shim it about 13 degree's over stock which is what you would get with axle shims on aftermarket springs. it would be a little more rugged and one less thing to break!

 

[Snitty]

if you have a cv driveshaft.. point the pinion toward the Tcase... if you have a universal joint driveshaft you need both ujoints bending at the same exact angle, which would mean you need to make sure the output and the pinion are parallel

 

[redrooster]

You should also factor in how much flex you have in the rear. THe misalignment will be greater when it flexes. I would point it 3 degrees lower than directly in line with the driveshaft.

 

[jps4jeep]

Rear axle

I was always told to match, or be close to factory pinion angle when swapping in a new rear.

But again, what do I know

 

[redrooster]

Technically you are supposed to match the angularity between the u-joint on the case and the u-jint on the pinion (parallel). Jeeps have such a short driveshaft that this isn't always feasible because the u-joint cannot handle as much misalignment. That is why I said put it 3 degrees lower. That way when it flexes it will get closer to being in line with the shaft and also will be better as the axle torques under load (axle wrap).
You can buy a magnetic angle finder from Harbor Freight for like $5 if you want to check the factory setting first then try to match it when you set up the new rear end.

 

[Snitty]

again.. if going CV style... go straight toward the output shaft... and like they said, maybe 3 degrees lower... but.. if going with just Ujoints.. you want them parallel, and parallel exactly.... if the rear compresses, or drops... it will remain parallel, and the angles will always be the same considering that... the ONLY time the pinion angle will change is under hard acceleration or deceleration

 

[Sully]

Already stated here but I will say it again. Dont point the pinion to the rear out put of the tcase unless it is a CV driveshaft. The pinion and the rear output shaft should be parallel.

 

[Craig]

Ok, so I'm confused now. I have an SYE kit and a cv driveshaft that I will be putting in when I put the new axle in but....even if I have a cv driveshaft and I point the pinion in line with the driveshaft, am I going to get the proper lube as jps4jeep stated? I've looked up many SOA installs on the net and a lot of them state a certain degree to set the pinion angle at and they're using SYE kits and cv driveshafts.

 

[Snitty]

you want the rear ujoint to be as straight as possible... when you are moving, the oil is flung all over the differential... you'll get it lubed enough

 

[Junkpile]

It can cause the rear to not be properly lubed if the pinion is tipped too high, but just pointing it up toward the Tcase output isn't going to do that unless you have a monster lift.