Is my pinion angle just right or too aggressive?

4BY4ADV

4BY4ADV

TJ Enthusiast
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Jan 2, 2020
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Location
Oceanside, CA
I plan on replacing the CA's at some point. I might even order some today... but ideally I want to get my Jeep back on the road ASAP. Sooner I feel comfortable driving it, the sooner I can sell one of my motorcycles and have even more money for Jeep upgrades.

After getting back from an 800 mile all highway road trip, I was feeling increased vibrations. I ordered the Advance Adapters SYE and Adam's DS package with intent to install it the following weekend, before I read tons of posts about pinion angle and needed adjustable CA's to address the pinion angle. Well, after getting under the Jeep again, I realize that my pinion is already angled up towards the TC.

I guess the question is whether I'm good to install it or is my angle too high? Jeep has both a suspension lift and 1" BL, so I'm wondering if the BL has my TC too low compared to where the pinion is pointing.

Pinion 0.jpg


**corrected from Atlas to Advance Adapters. Haven't had my coffee yet.**
 
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You absolutely cannot run with the pinion angle as high as yours is set, doing so will cause vibrations. With your factory driveshaft the pinion angle absolutely must be as shown in the bottom illustration above. They must be parallel. Your pinion angle would only be correct for an aftermarket double-cardan driveshaft as shown in the top illustration above.
 
I think you guys missed a part. I have an Advance Adapters SYE and an Adam's DS ready to be installed. I'm asking whether the angle looks appropriate for the SYE and DS I plan to install.

I'm asking prior to install as I don't want to install the SYE and new DS only to damage the brand new gear.

Thanks!

**corrected, AA not atlas**
 
Thanks Mikey!

Would I be risking any damage if I install the SYE/DS as it stands? This wouldn't be a long term, it just looks like most of the CA packages are going to be delayed a few weeks. I'd love to take my Jeep on a planned camping trip(all highway), but if I'm risking damaging brand new parts, I'll keep the Jeep garaged and pack up my motorcycle instead.
 
Looks like you may already have adjustable control arms. The Lower one in the picture isnt factory and I dont know how they would have gotten the pinion angle the way it is now with out adjustable arms.
 
You should double check your measurements for the new DS after you get the SYE on. Typically you should wait to order the DS until you can get exact measurements since there isn't just one they can send to everyone since most setups vary a bit.
 
PO lifted the Jeep. 1" BL and I'm not entirely sure of the suspension lift. Jerry has seen it in person and knew what it was... but I can't seem to remember. LCA's are aftermarket, UCA's are factory.

All the CA's will be replaced with adjustable CA's in the very near future. Leaning towards Core 4x4 Tier 4 based on beefiness and price, as well as JJ's on all ends.
 
rasband said:
You should double check your measurements for the new DS after you get the SYE on. Typically you should wait to order the DS until you can get exact measurements since there isn't just one they can send to everyone since most setups vary a bit.
Click to expand...


I called up Adam's prior to ordering. They seemed very confident in knowing DS lengths based on distance between the TC and pinion yoke when ordering both the SYE and DS together. Was my reason for going with Adams over others.
 
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M4LFUNCT10N said:
I called up Adam's prior to ordering. They seemed very confident in knowing DS lengths based on distance between the TC and pinion yoke when ordering both the SYE and DS together. Was my reason for going with Adams over others.
Click to expand...

I didn't know they did that, but it makes sense. Hopefully the install is smooth!
 
@Jerry Bransford In this picture, regarding the bottom image (for stock slip yoke setup). If the trans has a small downward angle, would you then raise the pinion a little to match that angle? The drawing shows them parallel with the ground and eachother. I'm thinking it's okay to not be exactly parallel with the ground so long as they are parallel with eachother.

Is that correct?

Pinion Angles.jpg
 
Don't worry about its angular relationship with the ground which doesn't matter. The only angular relationship that counts with that type of driveshaft is between the front and rear u-joints. With the OE factory style two u-joint driveshaft the pinion shaft and tcase output shaft just need to be parallel to each other.
 
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Jerry Bransford said:
Don't worry about its angular relationship with the ground which doesn't matter. The only angular relationship that counts with that type of driveshaft is between the front and rear u-joints. With the OE factory style two u-joint driveshaft the pinion shaft and tcase output shaft just need to be parallel to each other.
Click to expand...


That's what I figured....THANKS!
 
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