Specifically the Rubicon. Always wondered if with my tummy tuck, if I was right on the cusp of too much. 3.5" suspension lift and no BL. I've seen a lot worse but I've seen 2% a lot too.
How much angle is too much angle for the rear driveshaft?
- Thread starter ejay
- Start date
LONGJP2
TJ Expert
Until the pinion rotation causes the shock body to kiss the spring mounts.
I’m sure there is something to be said about starving the furthest pinion bearing.
I’m sure there is something to be said about starving the furthest pinion bearing.
OP
Don't have an angle finder. It's been so long since everything was installed and I remember measuring when installing but not what it was. Had the shaft rebuilt a few years ago and never thought to have it measured again for the record.
Pic is while on the driveway. Wall is probably 4% slope.
Pic is while on the driveway. Wall is probably 4% slope.
OP
No angle finder is needed, your rear pinion angle is a tad too high. And it gets even higher when you're accelerating. I'd drop that pinion angle down until it's pointing directly in line with the driveshaft and directly at the CV.
OP
With the TT, not sure how I'm supposed to do that. I'm going to get some different views at different ride/park angles to see how far it goes. It's served me well over the years but as stated, it's always been a tick in the back of my brain asking how far is too far? I suppose I wasn't crazy after all. Just a hair, but within reason.
tummy tuck has nothing to do with it. He's saying you need to lower your differential pinion, which would be done by shortening your upper control arms until the pinion yoke points directly in line with the driveshaft (zero operating angle of the rearmost u-joint).
OP
I can do that this weekend. Thanks. Any idea how that'll effect the front shaft angle?
FWiW, mine is sitting at 18.7deg on the double cardan. The pinon is maybe 1/2deg down. This is with a 4" spring and a Savvy skid. Been that way for several years and many thousands of miles.
And that’s probably the most you’ll see a pinion pointed up, you’ve got no worries OP
it might look a hair high at the pinion.
i think i'm 17.3* on the pinion into 18* on the drive shaft at a fat 3.5" of lift.
you could jack the ass up or put it onto a lift and let the rear axle droop out to full extension, and then be sure the shaft has no bind issues. other than that your no worse than any of us.
i think i'm 17.3* on the pinion into 18* on the drive shaft at a fat 3.5" of lift.
you could jack the ass up or put it onto a lift and let the rear axle droop out to full extension, and then be sure the shaft has no bind issues. other than that your no worse than any of us.
OP
I don't understand what lubes the pinion and how much fluid to put in doesn't it hurt the diff to tilt it up
The ring and pinion gears are spinning enough to toss the lube all over the place and keeps the bearings happy. I cant remember what angle mine is at but its very steep with a Savvy tuck and 4" lift. Ive put 100k miles on that way and haven't had a failure.
There are YouTube videos taken of the oil spray pattern inside a differential taken through a clear plastic cover... made clear so the lubricant spray pattern can be seen. Google them. The ring gear is what lifts the gear lube from the bottom and it heaves it forward with such force that the entire interior is continually drenched with gear lube. The pinion bearings get plenty (LOTS!!) of lubrication no matter what the pinion's angle is.